Instruments and Controls Identification

The ignition switch ( Fig. 2.4 ) can be turned to three positions: "Off," "Accessory," and "On." In addition, the same key locks and unlocks the cab doors, baggage door(s), and, if equipped, the bunk door(s).

In the "Off" position, the key slot is vertical; the key can be inserted and removed only in this position. The low beam headlights, taillights, brake lights, fog lights, dome lights, clearance lights, turn signals, hazard warning lights, utility and baggage lights, spotlights, electric wipers, horn, CB radio, power mirrors, cigarette lighter, clock, refrigerator, fuel heater, electric oil pan heater, and electric or diesel-fired engine-coolant preheaters can be operated in the off position (regardless of whether the key is inserted or not).

In the "Accessory" position, the key is turned counterclockwise. The auxiliary (bunk) fan, windshield fan(s), radio or stereo system, mirror heat, ether start system, air dryer, backup lights, and all of the electrical systems that are operable in the "Off" position are operable in the "Accessory" position.

In the "On" position, the key is turned clockwise. All electrical systems are operable. Low air- and oil-pressure warning lights and buzzer operate until the engine is started and pressure is built up. The engine can be started and operated only when the ignition switch is on.

For vehicles built to operate in Canada, switching on the ignition and releasing the parking brakes automatically activates the headlight low beams (later model vehicles) or high beams (earlier model vehicles) at half voltage as daytime running lights. The daytime running lights will operate until the parking brakes are applied; then they will switch off. Turning on the regular headlights will override the daytime running lights. The vehicle cannot be driven unless either the headlights or daytime running lights are activated.

With the ignition switch on, push the engine start button ( Fig. 2.4 ) to engage the electric or air starter. See the applicable engine operating instructions in Chapter 7 for complete starting instructions.

On vehicles equipped with a Neutral start switch, the transmission must be in Neutral before the engine can be started.

If the vehicle is equipped with an engine shutdown system with a manual override push button ( Fig. 2.4 ), simultaneously depress the engine start button and the manual override push button. Once the engine has started, release the engine start button, but continue to depress the override push button until the warning bell stops.

One or both outside door mirrors can be heated to keep them defrosted. Whenever the mirror heat switch ( Fig. 2.4 ) is on, an indicator light illuminates on the warning and indicator light module.

Both outside mirrors can be equipped with an electrical remote control. Move the toggle switch ( Fig. 2.4 ) to adjust the mirror.

The DDEC system is centered around a computer that is programmed to automatically control engine timing and fuel injection, providing maximum engine performance and fuel economy.

Some DDEC II® systems have an automatic engine shutdown option. This option will shut down the engine if potentially damaging conditions are detected. An override button (on DDEC II engines, this button is labelled "Override") is provided for emergency situations. It is mounted to the right of the ignition switch, and provides the driver with an extra 30 seconds of engine operating time.

Standard DDEC III® systems will shut down the engine if sensors indicate an emergency engine condition such as low coolant level, high coolant temperature, or high oil temperature. If such a condition occurs, the yellow "Check Engine" light in the lightbar will glow. If the problem gets bad enough to cause possible engine damage, the DDEC III will gradually cut engine power down to 70 percent of original power. At that point, the red "Shutdown Engine" light will turn on, and 30 seconds later, DDEC III will shut down the engine.

If DDEC III detects low oil pressure, both the "Check Engine" and "Shutdown Engine" lights will go on, and the engine will shut down in 30 seconds.

Once the engine has shut down, cycle the ignition key off and then on, and press the "Override/Chk" button to restart the engine.

The cruise control and PTO governor options are controlled in one of two ways:

By two switches on the instrument control panel ( Fig. 2.5 ). The "On/Off" switch turns on the cruise control option, and the spring-loaded "Set/Resume" switch selects the cruise speed or resumes cruise control after slowing down. For PTO operation, the "On/Off" switch turns on the PTO, and the "Set/Resume" switch either selects or resumes the engine operating speed.

or

By three optional buttons on the transmission shift knob ( Fig. 2.6 ). The "Pause" button allows the driver to temporarily interrupt cruise control. The "Resume" button allows the driver to resume the cruise speed after slowing down. The "Set" button allows the driver to select the cruise speed. For PTO operation, the "Pause" button temporarily interrupts PTO operation, the "Resume" button resumes PTO operation at the previously selected engine speed, and the "Set" button is used to select the engine operating speed. See Chapter 7 for complete instructions.

If the vehicle is equipped with Optimized Idle® , the cruise control "On/Off" switch is also used to control this option. Optimized Idle can be used to keep the engine oil warm, recharge the battery, and maintain sleeper temperature when the vehicle is parked for long periods. See Chapter 7 for more information and complete operating instructions.

The Caterpillar C-10, C-12, and C-15 electronic engines use a computer (electronic control module) to automatically control engine timing and fuel injection. The electronic features of these engines include an electronic governor, fuel-to-air ratio control, programmable engine ratings, injection timing control, fault analysis and recording, and a data link used for programming the electronic control module and troubleshooting the system.

All Caterpillar electronic engines have an engine check light in the lightbar located above the speedometer and tachometer. This warning light comes on or flashes if the engine oil pressure is low, the coolant temperature is high, the intake manifold air temperature is high, the coolant level is low (optional), or whenever there is a problem within the electronic engine system. Some vehicles equipped with Caterpillar electronic engines have an automatic engine shutdown option. This option will shut off fuel to the engine if potentially damaging conditions are detected. See the engine manufacturer's service literature for troubleshooting procedures.

The cruise control and PTO governor options are controlled in one of two ways:

By two switches on the instrument control panel ( Fig. 2.5 ). The "On/Off" switch turns on the cruise control option, and the spring-loaded "Set/Resume" switch selects the cruise speed or resumes cruise control after slowing down. For PTO operation, the "On/Off" switch turns on the PTO, and the "Set/Resume" switch either selects or resumes the engine operating speed.

By three optional buttons on the transmission shift knob ( Fig. 2.6 ). The "Pause" button allows the driver to temporarily interrupt cruise control. The "Resume" button allows the driver to resume the cruise speed after slowing down. The "Set" button allows the driver to select the cruise speed. For PTO operation, the "Pause" button temporarily interrupts PTO operation, the "Resume" button resumes PTO operation at the previously selected engine speed, and the "Set" button is used to select the engine operating speed. See Chapter 7 for complete instructions.

The BrakeSaver (optional on Caterpillar C-15 engines) is operated by a lever mounted in the cab. The lever controls the amount of oil being directed through the BrakeSaver. The time required to fill the BrakeSaver with pressure oil to the point of maximum braking in the BrakeSaver is about 1.8 seconds.

Cummins PACE, CELECT, and CELECT IV are electronic fuel control systems installed on model L10 and, for PACE only, Big Cam IV engines. These electronic engines are controlled by a microprocessor-based computer. This computer controls specific engine and vehicle speed modes of operation to maximize vehicle fuel economy and performance.

Vehicles with these engine systems have a yellow engine check light and a red engine stop light in the lightbar located above the speedometer and tachometer. With the ignition switch on, both lights come on for about two seconds; then, if there is no problem with the engine system, the lights will go out. Whenever there is a problem within the electronic engine system, one of the lights will come on and stay on as long as the problem exists.

If the yellow engine check light comes on while driving, some features will not work, but the vehicle can still be driven. If the red engine stop light comes on while driving, and if the engine will not accelerate, pull off of the road and shut down the engine. In either situation, have the problem repaired as soon as possible.

With the CELECT IV system—if the system is programmed to shut down—the engine shuts down 30 seconds after the red engine stop light comes on. The ignition switch will restart the engine after shutdown, but if the potentially damaging problem still exists, the engine will operate at the reduced speed or torque level allowed just prior to shutdown. To check whether a vehicle is equipped with CELECT or with CELECT IV, see the vehicle service manual.

The cruise control and PTO governor options are controlled in one of two ways:

By two switches on the instrument control panel ( Fig. 2.5 ). The "On/Off" switch turns on the cruise control option, and the spring-loaded "Set/Resume" switch selects the cruise speed or resumes cruise control after slowing down. For PTO operation, the "On/Off" switch turns on the PTO, and the "Set/Resume" switch either selects or resumes the engine operating speed.

or

By three optional buttons on the transmission shift knob ( Fig. 2.6 ). The "Pause" button allows the driver to temporarily interrupt cruise control. The "Resume" button allows the driver to resume the cruise speed after slowing down. The "Set" button allows the driver to select the cruise speed. For PTO operation, the "Pause" button temporarily interrupts PTO operation, the "Resume" button resumes PTO operation at the previously selected engine speed, and the "Set" button is used to select the engine operating speed. See Chapter 7 for complete instructions.

For cold weather starting, the vehicle may be equipped with one of several manual-control, ether start systems. To start the engine in cold weather, push the ether button ( Fig. 2.7 ), then start the engine. See the engine operating instructions in Chapter 7 for additional information.

The optional Sure Power Low Voltage Disconnect (LVD) system monitors battery power when accessories are being used when the engine is shut down. The system automatically turns off cab and sleeper accessories when voltage drops to 12.3 volts to ensure that there is enough battery power to start the vehicle. An alarm sounds for one minute before accessories are turned off. If no action is taken within that minute, the LVD module will shut off power to predetermined cab and sleeper circuits, and illuminate an LED indicator on the LVD module, located inside the baggage compartment. These circuits will remain off until the LVD measures 13.0 volts applied to the system, which can be done by starting the engine. After the engine is started, the system will reset.

All vehicles equipped with LVD should have a sticker on the dash indicating the presence of the system. Another sticker is located inside of the baggage compartment, along with the LVD module.

A battery isolator system has two or three regular batteries to turn the starter motor, and one or two gel cell batteries to provide power for cab and sleeper accessories when the engine is off. The system uses an isolator relay, which is normally open. The relay isolates the engine-starting batteries while the engine is not running, so that the engine can still be started even if the gel cell battery has been used to the point of complete discharge.

When all four batteries have a charge, the engine can be started in the normal manner, by turning the ignition key to the "Start" position and pressing the starter push button.

To start the engine when the gel cell battery is drained, press and hold the BATT BOOST push button ( Fig. 2.6 ) while pressing the starter push button. This will temporarily close the isolator relay, and connect the engine-starting batteries to the ignition switch for engine starting.

The isolator relay is closed only while the engine is running or the BATT BOOST push button is depressed. With the engine running, all four batteries are connected in parallel, allowing the alternator to charge them all, in addition to supplying power for all vehicle loads.

When the engine is not running, the gel cell provides all of the vehicle's electrical needs except for turning the starter motor. The gel cell is longer-lived and cheaper to use than a standard wet cell, but it can take a charge only within an extremely narrow range—13.8 to 14.1 volts.

At 14 volts, a gel cell has a very high charge acceptance rate. Because a truck charging system operates at approximately 14 volts, under normal conditions a gel cell will never need to be recharged with an external charger.

However, the single gel cell, like any other single battery, has limited current-supply capability, and will drain down faster than a standard multiple-battery installation that has no battery isolator system. Avoid ultra-deep discharging. Repeated ultra-deep discharging of a gel cell will reduce its life significantly.

To protect against ultra-deep discharging, a low voltage warning alarm and indicator light activate when the battery voltage falls to 12.0 volts or less. To silence the alarm, turn off all cab electrical loads or start the engine.

The FloScan Fuel-Tach is an electronic monitoring system that records fuel consumption and displays average miles per gallon. The Fuel-Tach gauge provides you with immediate feedback, showing a percentage difference between the current fuel consumption rate and the total trip miles per gallon average.

The system is controlled by a toggle switch. See Fig. 2.8 .

With nonelectronically controlled engines the "On" position allows you to receive average miles per gallon information for specific periods of time. In this position, the Fuel-Tach system stays on and stores the average miles per gallon information in memory, even if the engine is shut down.

In the IGN position, the Fuel-Tach system is on only when the ignition switch is on. Shutting down the engine cancels the information in memory.

With electronically controlled engines the digital display normally shows trip average miles per gallon. If the engine datalink sends an electronic fault code, the Fuel-Tach interrupts the miles per gallon display for 60 seconds, showing an "F" plus the fault code, for example, "F37." Fault codes are also stored in a history file for later viewing. For engine fault code instructions, see "Fuel Tach Gauge" in this chapter.

The "Reset" toggle switch cancels the information in memory used for calculating average miles per gallon and erases the fault code history file. To reset, press and hold the reset switch. The average MPG reading slowly blinks on and off for about 10 seconds, indicating that you are in the reset mode. After erasing the memory, the display blinks "Er" until you release the reset switch. If you release the reset switch before the display changes to "Er," the engine fault code history will be displayed and the memory will not be erased. After being reset, the display will show "0" MPG until you drive at least 150 feet (46 m).

The fog light switch ( Fig. 2.9 ) operates the fog lights, mounted on the bottom edge of the front bumper or recessed into the front bumper.

For vehicles built to operate in the United States, the low beam headlights must be turned on before the fog lights can be turned on. The fog lights won't go on if the high beam headlights are already on, and switching from low beams to high beams will switch off the fog lights.

For vehicles built to operate in Canada, the taillights and clearance lights must be on before the fog lights can be turned on. Unless the headlight switch is all the way up (headlights, taillights, clearance lights, marker lights, and panel lights on) or down (taillights, clearance lights, marker lights, and panel lights on), the fog light switch will not turn on the fog lights.

Utility lights can be swivel-mounted on top of the cab, mounted on the intake/exhaust support, or flush-mounted in the back of the cab or bunk. They are operated by the utility light switch ( Fig. 2.8 ) which, when turned on, also illuminates a red indicator light on the dash.

The circuit to the panel lamps is activated by the headlight switch. When the headlights are on, the panel lamp knob ( Fig. 2.8 ) controls the intensity of the instrument panel lamps. Turn the knob counterclockwise to brighten them and clockwise to dim them. Turning the knob counterclockwise to the peg will also turn off the panel lamps.

A three-position headlight switch ( Fig. 2.8 ) is used to operate the exterior lights. When the switch is up the headlights, and all other vehicle lights, are on. All vehicle lighting is off when the switch is in the middle position. When down, the switch activates only the clearance, instrument panel, and marker lights, and the taillights. The switch for the headlight high beams is built into the turn signal lever. When the headlights are on high beam, a green light in the warning and indicator light module goes on. The ignition switch must be on for the high beams to operate.

For vehicles built to operate in Canada, switching on the ignition and releasing the parking brakes automatically activates the headlight low beams (later model vehicles) or high beams (earlier model vehicles) at half voltage as daytime running lights. The daytime running lights will operate until the parking brakes are applied; then they will switch off. Turning on the regular headlights will override the daytime running lights. The vehicle cannot be driven unless either the headlights or daytime running lights are activated.

A spring-loaded interrupt switch ( Fig. 2.8 ) temporarily deactivates the marker lights and taillights. With the vehicle lights on, raise and release the interrupt switch to briefly turn off the marker lights and taillights.

Ceiling-mounted defogger fans are operated by "Low/Off/High" toggle switches located in the base of the fan.

Heater/air-conditioner controls ( Fig. 2.11 ) consist of two lever slide controls, a four-speed fan control switch, and a switch for the optional auxiliary heater fan. See Chapter 4 for detailed operating instructions of the heater/air-conditioner and the auxiliary heater.

Jake Brake controls consist of two dash-mounted toggle switches ( Fig. 2.12 ) which control the degree of engine braking. In conjunction with these switches, an engine-mounted microswitch (controlled by the throttle pedal) and an under-deck-mounted microswitch (controlled by the clutch pedal) actuate the engine brake.

See Chapter 7 , under the heading "Engine Braking System, Optional," for additional information.

Differential lockout, standard on all dual-drive vehicles, is driver-actuated by means of a "Lock/Unlock" control valve switch ( Fig. 2.12 ) mounted on the control panel. A red indicator light comes on whenever the interaxle differential is locked out (switch is in the lock position; no differential action between the drive axles). A guard around the switch prevents it from being accidentally activated.

The fifth wheel air slider valve permits repositioning of the sliding fifth wheel from inside of the cab. Moving the air slider control valve switch ( Fig. 2.12 ) to the lock position deactivates the control valve and locks the fifth wheel to the baseplate. Moving the switch to the unlock position activates the control valve and unlocks the fifth wheel slide mechanism, allowing changes to the total length of the tractor-trailer and changes to axle loads, to comply with varying state or provincial laws. A red indicator light, if so equipped, is illuminated whenever the fifth wheel slider is unlocked.

The yellow diamond-shaped knob ( Fig. 2.12 ) operates the parking brake valve. Pull the knob out to apply both the tractor and the trailer spring parking brakes. Push the knob in to release the tractor spring parking brakes. Before the spring parking brakes can be released, the air pressure in either air brake system must be at least 65 psi (447 kPa).

The red octagonal-shaped knob ( Fig. 2.12 ) operates the trailer air supply valve. After the vehicle and its air hoses are connected to a trailer, and the pressure in the air system is at least 65 psi (447 kPa), push the trailer air supply valve knob in (it should stay in) to charge the trailer air supply system and release the trailer spring parking brakes. Before disconnecting a trailer, or when operating a vehicle without a trailer, pull the trailer air supply valve knob out.

See Chapter 6 , under the heading "Brake System," for instructions regarding use of the trailer air supply valve and parking brake valve.

On vehicles equipped with an Eaton single-drive rear axle, a controlled traction differential feature is standard. A control valve switch ( Fig. 2.13 ) engages and disengages the controlled traction feature. A guard is positioned around the switch to prevent it from being accidentally activated.

See Chapter 9 for complete operating instructions.

The air suspension dump valve allows the air in the vehicle air suspension to be quickly exhausted, lowering the rear of the vehicle. This makes it easier to connect to or disconnect from a trailer. A control valve switch ( Fig. 2.14 ) exhausts and fills the air suspension. To exhaust air from the suspension, move the switch to LOWER. A guard is positioned around the switch to prevent it from being accidentally activated.

The AirLiner Plus suspension is used on vehicles with pusher or tag axles to improve traction performance. The system maintains an accurate leveling of frame height whether the vehicle is in motion or parked. The Meritor WABCO® ECAS (Electronically Controlled Air Suspension) system uses a height sensor mounted between the frame and the drive axle housing as well as other sensors to provide frame height information to a control unit mounted inside of the cab. The electronic control unit quickly lowers or raises the frame height, as necessary. Altering the height of the frame while the vehicle is parked can be performed using a hand-held remote control unit.

For the optional automatic function to work, the vehicle must be equipped with a rear axle air suspension and ABS. Automatic Traction Control is recommended for optimal vehicle traction control.

A Henke automatic engine idler/timer ( Fig. 2.15 ) allows the driver to select the idle time required for engine shutdown. The driver can turn off the ignition, remove the ignition key, lock the vehicle, and leave it with the engine idling. The automatic timer will shut the engine off at the end of the selected time.

Push the lighter in ( Fig. 2.16 ) to heat the element. The lighter will stay in and will automatically pop out when the element is hot.

A toggle switch ( Fig. 2.16 ) controls the air window. Push the switch up to raise the window, or push it down to lower the window.

An antenna connection and positive (+) and negative (–) power connections are provided for a CB radio. See Fig. 2.16 .

The turn signal lever ( Fig. 2.17 ) is mounted on the steering column. Pushing the lever counterclockwise turns on the left-turn signal lights; pushing it clockwise turns on the right-turn signal lights. When one of the turn signal lights is on, a green indicator light flashes at the far left or far right of the warning and indicator light panel. To cancel the signal, return the lever to the neutral position, except when equipped with an optional self-canceling switch.

The hazard warning light tab ( Fig. 2.17 ) is located below the lever on the turn signal switch. Activate the hazard warning lights by pulling the tab out. When the hazard warning light tab is pulled out, all of the turn signal lights and both of the indicator lights on the control panel will flash. To cancel the warning lights, move the turn signal lever up or down.

The headlight dimmer ( Fig. 2.17 ) may be a push button at the end of the turn signal lever, or a lift-handle type built into the turn signal lever.

To operate the push button type dimmer, press the button once to change from low beam to high beam headlights; press it again to cancel the high beam lights.

To operate the lift-handle type dimmer, pull the turn signal lever up to change from low beam to high beam headlights, or from high beam back to low beam.

When the headlights are on high beam, a green light on the indicator light panel comes on. For vehicles built to operate in the United States, switching from low beams to high beams will switch off the fog lights.

This lever is used for applying the trailer brakes without applying the truck or tractor brakes and is mounted on the steering column. See Fig. 2.17 . See Chapter 6 under the heading "Brake System," for operating instructions.

If so equipped, the transmission range control valve and splitter valve are attached to the gearshift knob. Transmission shift pattern labels are located on the header or sun visor above the driver's windshield.

See Chapter 8 for complete transmission operating instructions.

All adjustment controls for a suspension seat are located on the seat base. See Chapter 5 for complete instructions.

For vehicles with a single dome light mounted on the roof inside of the cab, the light is operated by a three-position switch mounted in the dome light. The switch provides both a low- and a high-intensity setting; in the middle position, the dome light is off.

For vehicles with a single dome light and two reading lights mounted on the roof inside of the cab, each light is operated by its own on/off switch, mounted in the dome light.

The tilt steering wheel ( Fig. 2.18 ) has a tilt range of 15 degrees, and a telescoping range of 2-5/8 inches (67 mm). A control lever is located just below the turn signal switch on the steering column.

After adjusting the seat to the desired ride position, unlock the steering column by pushing the control lever and holding it all the way down. Tilt the steering column to the desired position, then release the control lever to lock the steering column in place.

To adjust the height of the steering wheel, pull upward on the control lever. While holding the control lever in this position, move the steering wheel upward or downward to the desired position. Release the control lever to lock the steering wheel in place.

The red parking brake indicator light ( Fig. 2.19 ) comes on whenever the parking brakes are activated and the ignition is on.

Additional optional lights may be installed in the center dash.

The Meritor WABCO® Antilock Braking System (ABS) may have up to three of the following amber lights (the first two are standard: a tractor warning light (TRAC ABS), a wheel spin indicator light (WHL SPIN), and an optional trailer warning light (TRLR ABS). Vehicles built before July, 1994, also have a DEEP SNOW/MUD indicator light.

With the tractor ABS system, the tractor warning light (TRAC ABS) comes on after the engine is started ( Fig. 2.19 ). Once the vehicle moves faster than about 4 mph (6 km/h), the warning light goes out only if all of the tractor's ABS components are working.

With the tractor and trailer ABS system, the vehicle also has a trailer warning light labelled TRLR ABS ( Fig. 2.19 ).

After the engine is started, the TRLR ABS light comes on if the trailer is equipped with a compatible ABSsystem. Once the vehicle moves faster than about 4 mph (6 km/h), the TRLR ABS warning light goes out only if all of the trailer's ABS components are working. For more detailed information about TRLR ABS light operation, see Chapter 6 .

The wheel spin indicator light (WHL SPIN) comes on flashing if one of the drive wheels spins during acceleration ( Fig. 2.19 ). The flashing light goes out when the wheel stops spinning. A label ( Fig. 2.21 ) on the dash explains what actions should be taken when the WHL SPIN indicator light starts to flash.

If equipped with an electronic engine, an automatic traction control (ATC) system may be installed. On these vehicles, the ATC system automatically controls wheel spin during reduced-traction starts.

An "ATC Function" switch (if equipped), allows the driver to select from two levels of drive axle traction-control assistance:

The Deep Snow/Mud mode is indicated by a flashing WHL SPIN light. To engage this mode, the ATC function switch must be in the Normal position when the vehicle is initially powered up. Once the vehicle is started, the ATC function switch can be set to the Deep Snow/Mud position. The ECU indicates this change by a constant flashing of the WHL SPIN lamp (or by illumination of the Deep Snow/Mud light on vehicles built before July, 1994).

If the ATC function switch is in the Deep Snow/Mud position when the vehicle is powered up, the ECU will not accept this function change and will remain in the Normal mode. Indication of this condition will be the absence of the flashing WHL SPIN light (on vehicles built before July, 1994, the absence of an illuminated Deep Snow/Mud light). To engage the Deep Snow/Mud mode in this situation, change the position of the ATC function switch to the Normal mode. After two seconds, move the switch to the Deep Snow/Mud position. When this occurs, the indicator light will activate as previously described.

The "ABS Chk" switch (if equipped), activates blink code diagnostics, which are used to read ABS and ATC system fault codes on the WHL SPIN light. This switch is located in the lower dash panel cover, just below the ignition switch, on the left side of the steering wheel. When turned on (in the "up" position), blink code diagnostics are activated. See Group 42 of the Heavy-Duty Trucks Service Manual for troubleshooting procedures.

See the brake system operating instructions in Chapter 6 for more information.

With the Bendix Antilock Braking System (ABS), the tractor warning light (TRAC ABS) comes on after the key is turned on ( Fig. 2.19 ). The warning light goes out only if all of the tractor's ABS components are working properly.

If the tractor is attached to a trailer with a compatible ABS system, the trailer ABS warning lamp (TRLR ABS) will also come on momentarily after the key is turned on.

Vehicles equipped with a Bendix ABS system may also be equipped with an automatic traction control (ATC) system. The ATC system automatically controls wheel spin during reduced-traction starts.

The wheel spin indicator light (WHL SPIN) comes on if one of the drive wheels spins during acceleration ( Fig. 2.19 ). The light goes out when the wheel stops spinning. The Bendix system will either reduce engine torque or apply gentle brake pressure to force the differential to drive the stationary or slowly spinning wheel. If slippery road conditions continue, engage the axle lock.

See the brake system operating instructions in Chapter 6 for more information.

The VIGIL II system is an electronically controlled warning and engine shutdown system. It controls the turn signal functions and various optional functions. A solid state lightbar ( Fig. 2.22 ) in the instrument panel contains displays for the functions.

The VIGIL III system is an electronically controlled warning system with maximum vehicle speed control, vehicle overspeed reporting, and optional engine shutdown. It controls the turn signal functions and various optional functions. A solid-state lightbar ( Fig. 2.23 ) in the instrument panel contains displays for the functions.

The Kysor VIP system is an electronically controlled warning and engine shutdown system. It also controls the turn signal functions and various optional functions. A solid state lightbar ( Fig. 2.22 ) in the instrument panel contains displays for the functions.

The DDU controls system power, range for vehicle warnings, speaker volume, and all other system functions. At the lower front edge of the DDU, a slot is provided to insert the optional driver's identification card. Alert and indicator lights advise of multiple warning levels, system power, system failure, and, if so configured, failure of the driver to insert the identification card.

A light sensor automatically adjusts alert and indicator light brightness depending on cab lighting conditions. A small speaker provides audible alert tones to warn of closing on an object ahead and, when equipped with an optional side sensor, of objects alongside when the turn signal is activated in preparation for a lane change. Additional tones indicate speaker volume, system failure, driver's card status, and data extraction pass or fail.

Certain special road situations may affect the system's ability to detect objects. These situations include the effects of curves, dips, and hills which can provide an unexpected result:

The optional vehicle accident reconstruction capability provides two segments of system data, one of which can be stored in system memory. Push and hold the DDU range knob for at least 5 seconds to store the first segment. Within 6 seconds, the green SC indicator light will blink rapidly 8 times, confirming that the data has been saved. If the range knob is pushed again, a fail tone will sound. After the first segment is saved, the second segment runs continuously, but only contains the last 10 minutes (approximately) of system data. The system will cease recording data 30 seconds after the vehicle comes to a stop.

A tachometer ( Fig. 2.19 ) indicates engine speed in revolutions per minute (rpm), and serves as a guide for shifting the transmission and keeping the engine in the appropriate rpm range. For low idle and rated rpm, see the engine identification plate.

An optional tachometer is equipped with an engine hour meter to record continuous operating hours of the engine. In cases where actual mileage doesn't indicate overall usage, maintenance and lubrication intervals for the engine and engine-operated equipment can be determined by operating hours.

A speedometer ( Fig. 2.19 ) registers speed in both miles per hour (mph) and kilometers per hour (km/h). Standard speedometer gauges are equipped with a seven-digit odometer that records total distance traveled.

An optional speedometer is equipped with a seven-digit odometer, and a four-digit odometer that records trip distance. The trip odometer can be reset to zero by pressing a button near the lower edge of the gauge face.

During normal engine operation, the water temperature gauge ( Fig. 2.26 ) should read 175 to 195°F (79 to 91°C). If the temperature remains below 160°F (71°C) or exceeds the maximum temperature shown in Table 2.2 , inspect the cooling system to determine the cause. See the Heavy-Duty Trucks Service Manual for troubleshooting and repair procedures.

The oil pressure gauge ( Fig. 2.26 ) should read as shown in Table 2.3 .

A pyrometer ( Fig. 2.26 ) registers the exhaust temperature near the turbocharger. Normal exhaust temperatures are listed in Table 2.4 .

Variations in engine load can cause exhaust temperatures to vary. If the pyrometer reading shows that exhaust temperature exceeds normal, throttle less fuel to the engine until the exhaust temperature is reduced. Shift to a lower gear if the engine is overloaded.

The voltmeter ( Fig. 2.27 ) indicates the vehicle charging system voltage when the engine is running and the battery voltage when the engine is stopped. By monitoring the voltmeter, the driver can be aware of potential charging system problems and have them fixed before the batteries discharge enough to create starting difficulties.

The voltmeter will normally show approximately 13.7 to 14.1 volts when the engine is running. The voltage of a fully charged battery is 12.7 to 12.8 volts when the engine is stopped. A completely discharged battery will produce only about 12.0 volts. The voltmeter will indicate lower voltage as the vehicle is being started or when electrical devices in the vehicle are being used.

If the voltmeter shows an undercharged or overcharged condition for an extended period, have the charging system and batteries checked at a repair facility.

On a vehicle equipped with a battery isolator system, the voltmeter measures the average voltage of all of the batteries when the engine is running. When the engine is stopped, the voltmeter shows only the gel cell battery voltage and does not indicate the voltage of the engine-starting batteries.

The FloScan Fuel-Tach ( Fig. 2.27 ) is an electronic monitoring system that records fuel consumption and displays average miles per gallon. The Fuel-Tach provides you with immediate feedback showing a percentage difference between the current fuel consumption rate and the total trip miles per gallon average.

The "0" point on the gauge means that the current fuel consumption rate is the same as the miles per gallon average of the total trip distance traveled.

Clockwise movement (into the green zone) of the gauge needle shows the percentage improvement in the current fuel consumption rate compared to the miles per gallon trip average.

Counterclockwise movement (into the red zone) of the gauge needle shows that the current fuel consumption rate is higher than miles per gallon trip average. Needle movement into the red zone means that the driver should shift the transmission or change vehicle speed to increase fuel efficiency, as driving conditions permit.

The Fuel-Tach system is operated by a toggle switch. For switch operating instructions, see "Fuel-Tach Switch" in this chapter.

The Fuel-Tach system installed in vehicles with electronic engines also displays fault codes corresponding to any engine problems that might occur. When the engine databus sends a fault code, it interrupts the LED miles per gallon display for 60 seconds. An "F" appears in the display together with the fault code, for example "F37." If the engine sends a single fault code, the display blinks on and off for 60 seconds while displaying the code. It then goes back to displaying the MPG. If the engine sends more than one fault code, the display blinks each fault code on and off three times and keeps repeating them for 60 seconds. It then goes back to reading MPG. To find out the engine problem, look up the displayed number in your engine fault code list.

If you need to review the fault codes received, simply press and release the "Reset" toggle switch to display the fault code history file. The display shows "h" plus each fault code starting with the most recent, for example, (h13, h27, h17). Each code blinks three times before showing the next code. After showing all of the codes, the display shows "- -" and then goes back to displaying MPG. If there are no fault codes in the history file, the display blinks "- -" four times and goes back to showing MPG. The history file may be viewed at any time.

If there are multiple active fault codes, they are sent sequentially by the engine databus. The sequence repeats as long as the faults are not corrected. Any code appears in the history file only once even though the sequence of codes is repeating. If you view the history file several times in a short period of time, the order of the codes may change depending on which code of the repeating sequence was sent most recently.

An engine hour meter records continuous operating hours of the engine and is mounted in the control panel. In cases where actual mileage does not indicate overall usage, maintenance and lubrication intervals for the engine and engine-operated equipment can be determined by operating hours.

An application air pressure gauge ( Fig. 2.27 ) registers the air pressure being used to apply the brakes and should be used for reference only. The gauge will not register air pressure until the foot brake pedal is depressed or the trailer hand brake is applied.

A dual system air pressure gauge ( Fig. 2.27 ) registers the constant pressure in the primary and secondary air systems. Normal pressure, with the engine running, is 100 to 120 psi (689 to 827 kPa) in both systems. A low-air-pressure warning light and buzzer, connected to both the primary and secondary systems, activates when air pressure in either system drops below a minimum pressure of 64 to 76 psi (441 to 524 kPa). When the engine is started, the warning light and buzzer remain on until air pressure in both systems exceeds minimum pressure.

The fuel gauge ( Fig. 2.27 ) indicates the level of fuel in the fuel tank(s). If equipped with a second (optional) fuel gauge, each fuel tank level is indicated on a separate gauge.

An intake-air restriction gauge ( Fig. 2.28 ) measures the vacuum on the engine side of the air cleaner at the air cleaner outlet. Vacuum is measured in inH₂O (inches of water). Service the air cleaner when the vacuum reading equals the applicable level shown under "Service" in Table 2.5 .

An intake-air restriction indicator ( Fig. 2.29 ) measures the vacuum on the engine side of the air cleaner at the air cleaner outlet. If the yellow signal stays locked at or above the values shown in Table 2.5 , after the engine is shut down, service the air cleaner. Then, press the yellow button to reset the indicator.

A fuel pressure gauge ( Fig. 2.28 ) registers output pressure of the fuel pump. Whenever the engine is operating, the fuel pressure reading should be constant. If the fuel pressure drops, investigate the cause and make the necessary repairs.

An ammeter measures current flowing to and from the battery. When the batteries are charging, the meter needle moves to the plus side of the gauge; when the batteries are being discharged, the needle moves to the minus side.

During normal operation, the engine oil temperature gauge ( Fig. 2.28 ) should read:

Under heavy loads, such as when climbing steep grades, temperatures which exceed the normal oil temperature range for a short period are not unusual.

During normal operation, the transmission oil temperature gauge ( Fig. 2.28 ) reading should not exceed 250°F (121°C) for Eaton-Fuller transmissions.

During normal operation, forward and rear differential oil temperature gauges ( Fig. 2.28 ) should read between:

Under heavy loads, such as when climbing steep grades, temperatures up to a maximum of 250°F (121°C) are not unusual.

A turbocharger boost gauge ( Fig. 2.28 ) measures the pressure in the intake manifold, in excess of atmospheric pressure, being created by the turbocharger.

A Pana-Pacific clock ( Fig. 2.28 ) has black characters on a constantly backlighted green display, with a brightness that automatically adjusts for day or night. The clock has a 24-hour alarm, with a 3-minute snooze feature.

A Kysor digital clock ( Fig. 2.14 ) has a constant red display, which automatically adjusts the brightness for day or night. The clock features a 24-hour alarm.

A Sangamo tachograph ( Fig. 2.30 ) indicates and records vehicle speed, time, and distance traveled. It also records the length of time the engine is operated when the vehicle is stationary. A warning light comes on whenever a preestablished speed limit is exceeded.

The switch is used whenever service operations require that the batteries be disconnected. It is also used whenever the vehicle is placed out of service for extended periods, to prevent battery discharge. See Fig. 2.31 .