Instruments and Controls Identification

When the ignition is turned on, the ICU runs a self-check. Observing the ignition sequence is a good way to ensure the ICU is functioning properly.

When the ignition is turned on, the following actions should occur:

If the ICU receives active fault codes, it displays them one after the other until the parking brake is released or the ignition is turned off. Once the parking brake is completely released, the ICU displays the odometer. If there are no active faults, the ICU displays the odometer after the self-check completes.

When the self-check is complete on an ICU4M, the fasten seat belt screen displays if the engine is off. If the engine is running, the idle hours screen displays.

See Fig. 2.4 for an explanation of the aftertreatment system (ATS) warning indicators, and actions required to avoid further engine protection steps.

The STOP engine lamp illuminates when the engine protection system is activated in one of two ways. On some engines, the engine protection system derates the engine, allowing it to run at lower rpm and slower vehicle speed. Drive the vehicle to a safe location or to a service facility.

On other engines, the engine protection system shuts down the engine. It first derates the engine, then shuts it down completely 30 to 60 seconds after the indicator illuminates (depending on the critical fault type) if the condition does not improve. Bring the vehicle to a stop on the side of the road before the engine shuts down.

Some vehicles may have a shutdown-override switch, which may be used to momentarily override the shutdown sequence. See Chapter 7 for detailed information regarding the shutdown process.

To restart the engine, turn the ignition switch to OFF for a few seconds, then turn the ignition switch to ON and let the gauge sweep complete before starting the engine. The engine will run for a short period and shut down again if the condition does not improve.

A mode/reset button, located on the right side of the ICU instrument cluster, is used to control the driver message center. See Fig. 2.1 . Tap the mode/reset button to advance one screen; press and hold the button to select a menu choice or reset the display. When the display resets, an audible chirp sounds.

Only four screens are accessible when the parking brake is off (mobile screens). All screens are accessible when the parking brake is on (stationary screens).

The air intake restriction gauge indicates the vacuum on the engine side of the air cleaner. See Fig. 2.18 . On standard installations, it is mounted on the air cleaner. As an option for easier viewing, an air intake restriction indicator can be mounted on the auxiliary dash panel.

Air intake restriction vacuum is measured in inches of water (inH₂O). For vehicles equipped with a graduated indicator or a restriction gauge on the dash, check the gauge with the engine off. If the yellow signal stays locked in the red zone once the engine is shut down, or is at or above the values shown in Table 2.2 , the air cleaner element requires replacement.

Vehicles may be equipped with a go/no-go restriction indicator without graduations (see Fig. 2.19 ) instead of a graduated indicator.

If air restriction exceeds the maximum allowable value, operate the vehicle for one more day, making sure not to run the engine over rated rpm. Refer to the engine operation manual for more information on rated rpm for your engine.

If air restriction exceeds the maximum value again, replace the air cleaner element. For instructions, refer to Group 09 of the Century Class Trucks Workshop Manual .

An application air pressure gauge 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.

During normal engine operation, the coolant temperature gauge should read between 175 and 195°F (79 and 91°C). If the temperature remains below 160°F (71°C), inspect the cooling system to determine the cause.

If the temperature exceeds the maximum temperature shown in Table 2.3 , inspect the cooling system to determine the cause. See the Century Class Trucks Workshop Manual for troubleshooting and repair procedures.

If coolant temperature rises above the maximum temperature listed in Table 2.3 on EPA07 engines, the CHECK engine lamp will illuminate. If the condition does not improve, the STOP engine lamp will also illuminate and an audible warning will sound. The engine will then derate or shut down, depending on the type of engine protection system installed.

During normal operation, drive axle oil temperature gauges should read as follows:

Under heavy loads, such as when climbing steep grades, temperatures that exceed the normal oil temperature range for a short period are not unusual. If the temperature returns to normal when the load decreases, there is no problem.

The engine oil pressure gauge displays the current engine oil pressure. If engine oil pressure falls below the minimum levels shown in Table 2.4 , the CHECK engine lamp will illuminate. If the condition does not improve, the STOP engine lamp will also illuminate and an audible warning will sound. The engine will then derate or shut down, depending on the type of engine protection system installed.

During normal operation, the optional engine oil temperature gauge should read:

Under heavy loads, such as when climbing steep grades, temperatures that exceed the normal oil temperature range for a short period are not unusual. If the temperature returns to normal when the load decreases, there is no problem.

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

Air pressure gauges register the 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 audible alert, connected to both the primary and secondary systems, activate when air pressure in either system drops below 64 to 76 psi (441 to 524 kPa).

When the engine is started, the warning light and audible warning remain on until air pressure in both systems exceeds minimum pressure.

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

The speedometer registers speed in both miles per hour (mph) and kilometers per hour (km/h).

The tachometer 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.

The transmission fluid temperature gauge indicates the transmission lubricant operating temperature. Temperatures vary by application, but the transmission fluid temperature gauge reading should not exceed 250°F (121°C).

Under heavy loads, such as when climbing steep grades, temperatures that exceed the normal oil temperature range for a short period are not unusual. If the temperature returns to normal when the load decreases, there is no problem.

A turbocharger boost pressure gauge indicates the pressure in the intake manifold, in excess of atmospheric pressure, being created by the turbocharger.

The voltmeter indicates the vehicle charging system voltage when the engine is running and the battery voltage when the engine is off. By monitoring the voltmeter, the driver can stay aware of potential battery charging problems and have them fixed before the batteries discharge enough to create starting difficulties. Vehicles are equipped with either a voltmeter gauge, or a digital voltmeter readout located on the bottom line of the dash message center.

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 off. Battery voltage under 12.0 volts is considered a low battery, and a completely discharged battery will produce only about 11.0 volts.

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

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

Cruise control is activated by two dash-mounted switches: an On/Off switch and a Set/Decelerate/Resume/Accelerate switch. See Fig. 2.24 .

To turn the engine fan on, press the upper half of the engine fan switch. See Fig. 2.25 . The fan will continue to operate for a set amount of time and then turn off unless the coolant temperature is high enough to continue fan operation. To turn the fan off before the set time period ends, press the lower half of the switch.

The ignition switch has four positions: OFF, ACC (accessory), ON, and START. The ignition key also locks and unlocks the cab doors, baggage door(s), and if equipped, the bunk door(s).

In the OFF position, the ignition switch is vertical. The key can be inserted and removed only in the OFF position.

The following functions are operable when the ignition switch is in the OFF position (regardless of whether the key is inserted):

Turn the key counterclockwise to reach the ACC position. In addition to all the functions that are operable in the OFF position, the following functions are operable when the switch is in the ACC position:

Turn the key clockwise past the OFF position to reach the ON position. When the ignition is turned on, the following actions should occur:

Turn the key clockwise past the ON position to reach the START position to start the engine. Release the key the moment the engine starts. Do not operate the starter longer than thirty seconds, then allow the starter to cool between attempts. If the starter overheats, the starter protection system will prevent operation of the starter until it has cooled. Release the key the moment the engine starts.

To activate the PTO function, press the upper half of the switch. Press the lower half of the switch to deactivate the PTO function.

Adjust the seat to the desired ride position, then tilt or telescope the steering column as needed.

To tilt the steering column, press down on the foot pedal located on the steering column. Tilt the steering column up or down to the desired position. Release the foot pedal to lock the steering column in place.

To telescope the steering column, press down on the foot pedal located on the steering column. Pull the steering wheel closer to you or push the steering wheel away from you. Release the foot pedal to lock the steering column in place.

The wipers are operated by a dual paddle switch located on the auxiliary instrument panel. See Fig. 2.27 . To turn the wipers on or off, press the top paddle in. When the top paddle is pushed up, the wipers will operate at high speed; when it is pushed down, they will wipe at low speed.

The bottom paddle, when pushed in, turns the washers on. When pressed for less than ½-second, the wipers will perform a single, low speed dry wipe (mist function). When pressed for more than ½-second, the wash cycle begins and continues for three cycles or until the paddle is released. When the bottom paddle is pushed up, the wipers operate in fast delay. When the bottom paddle is pushed down, the wipers operate in slow delay. With the wipers in delay mode (fast or slow), push the bottom paddle up to shorten the delay period, or push the paddle down to lengthen it.

The roll stability system uses a lateral-acceleration sensor that monitors rollover risk. Shortly after a curve, lane change, or other driving maneuver that results in a rollover-risk detection, a dash warning light illuminates, an audible tone sounds, and a driver advisory message is displayed in the driver message center. The purpose is to advise the driver that the previous maneuver produced a rollover risk.

The roll stability advisor displays different text messages depending on the severity of the risk of each occurrence of risky driving. From the highest risk level to the lowest risk level, the system will sound an audible alert, and display a message, as shown in Fig. 2.30 .

Bring the vehicle to an authorized service facility if a system failure message is displayed.

The roll stability control system automatically reduces engine power, applies the engine brake, and/or applies the tractor and trailer brakes when the acceleration sensor detects that the vehicle is at risk of rolling over. The control can intervene even before an advisory message is displayed.

The dash indicator light illuminates whenever the roll stability control system intervenes.

The hard-braking advisor uses the information from the ABS wheel speed sensors to determine when braking is severe enough to produce lockup at one or more wheels on the tractor, and/or very rapid vehicle deceleration. Shortly after a hard-braking event occurs, an advisory message is displayed in the driver message center, indicating that the braking behavior was too aggressive for the current road surface conditions. This system is not a replacement for a driver's good judgment. Sometimes it is necessary to brake hard.

From the highest risk level to the lowest risk level, the system will sound an audible alert, and display a message, as shown in Fig. 2.30 .

The driver message center records the number of messages received, and displays the number of messages as counts. Roll stability advisor (RSA) and hard-braking event data (HBED) counts can be viewed in the trip advisory screen, and the leg advisory screen.

Counts can be reset using the + key on the steering wheel. Clearing RSA and HBED leg counts will also reset the leg miles and leg hours. Clearing RSA and HBED trip counts will also reset trip miles, trip hours, leg miles, leg hours, and leg advisory counts. In addition, resetting leg miles will clear leg counts. Clearing trip miles will reset miles, hours, and counts in both the leg and trip screens.

The TRIP and LEG advisor screens count both the roll stability advisories (ROLL) and hard-braking events (BRK). For example, if during a TRIP, the driver message center recorded the events in Table 2.5 , the message center would display as shown in Fig. 2.31 .

If the count reaches more than 9 occurrences an up-arrow symbol will appear, to indicate to the driver that the count has exceeded 9 counts. See Fig. 2.32 .