Instrumentation Control Units

4700 d 03.01.000

The instrumentation control unit (ICU) provides the driver with engine and vehicle information. It is comprised of standard and optional gauges, an audible warning, a driver message center, and a lightbar containing warning and indicator lamps (also known as telltales). Warning and indicator lamps illuminate in red (danger), amber (caution), green (status advisory), or blue (high-beam headlights active).

Western Star 5700 vehicles are equipped with an ICU4Me. See Fig. for a typical ICU layout.

The following headings in this chapter provide additional information and operating instructions for ICU components:

"Warning and Indicator Lights"
"Instruments"
"Driver Message Center"

Voltmeter

Turbocharger Boost Pressure Gauge

Trailer Air Supply Gauge

Engine Oil Temperature Gauge

Transmission Oil Temperature Gauge

Tachometer and Coolant Temperature Gauge

Fuel/DEF Level Gauge

Speedometer and Engine Oil Pressure Gauge

Suspension Air Pressure Gauge

Forward Drive-Axle Temperature Gauge

Rear Drive-Axle Temperature Gauge

Trailer Suspension Air Pressure Gauge

Secondary Air Pressure Gauge

Primary Air Pressure Gauge

Driver Message Center

Fig. 1, ICU4Me Instrument Cluster

Ignition Sequence

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

Important: Do not crank the engine until the ICU self-check is complete.

Note: Primary and secondary air pressure gauges are the only air gauges that complete a sweep of their dials during the ignition sequence.

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

electronic gauges complete a full sweep of their dials
warning and indicator lamps illuminate, then are extinguished
audible alert sounds for approximately four seconds or until sufficient air pressure builds up in the primary and secondary air systems
DEF level indicator illuminates all segments green, then turns them off one at a time before turning the leftmost segment amber and then red
Western Star logo displays on the ICU4Me driver message center for two seconds.
software revision level of the ICU is displayed on the driver message center, followed by any active faults

Important: If any red or amber warning and indicator lamps do not illuminate during the ICU self-check or do not go out after the self-check completes, take the action outlined, see Table., then take the vehicle to an authorized Western Star service facility as soon as possible.

Note: If active faults are present, take the vehicle to an authorized Western Star service facility as soon as possible.

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 home screen. If there are no active faults, the ICU displays the home screen after the self-check completes.

Fig. 2, ICU Ignition Sequence

Audible Alerts

An audible alert sounds during the ignition sequence and whenever one of the following conditions exists:

Engine oil pressure falls below the minimum preset value.
Coolant temperature rises above the maximum preset value.
Air pressure falls below approximately 70 psi (483 kPa).
Parking brake is set with the vehicle moving faster than two miles per hour.
System voltage falls below 11.9 volts.
Door is open or the headlights are on, with the parking brake off.
Driver seat belt is not fastened with the parking brake off (optional).
Outside temperature falls below 35°F (1.7°C) (optional).

Table 1, Common Warning and Indicator Lamps

Common Warning and Indicator Lamps
Lamp Description			Color
	STOP Engine^*	Indicates a serious fault that requires engine shutdown immediately. The engine protection system will reduce the maximum engine torque and speed, and, if the condition does not improve, will shut down the engine within 30 to 60 seconds. Safely bring the vehicle to a stop on the side of the road and shut down the engine as soon as the red light is seen. If the engine shuts down while the vehicle is in a hazardous location, turn the key to the OFF position for a few seconds, then restart the engine and move the vehicle to a safer location.	Red
	High Coolant Temperature	Indicates the coolant temperature is above the maximum allowable temperature.	Red
	Low Air Pressure (EPA10 and Newer)	Indicates air pressure in the primary or secondary reservoir has dropped below approximately 70 psi (483 kPa).	Red
	Low Air Pressure (ICU4Me only, mid-GHG14)	Indicates air pressure in the primary or secondary reservoir has dropped below approximately 70 psi (483 kPa).	—
	Low Engine Oil Pressure	Indicates the engine oil pressure is below the minimum allowable pressure.	Red
	Transmission Overheat	Indicates high transmission temperature.	Red
	Transmission Fluid Level	Indicates low transmission fluid level. Safely bring the vehicle to a stop as soon as possible.	Red
	Parking Brake (EPA10 and Newer)	Indicates the parking brake is engaged.	Red
	Low Battery Voltage	Indicates that battery voltage is 11.9 volts or less.	Red
	Unfastened Seat Belt	Activates with an audible alert when the system detects that the parking brake is off and the driver seat belt is not fastened on some vehicles. On other vehicles, this lamp illuminates for 15 seconds when the ignition is first turned on.	Red
	Check ECAS	Indicates Electronically Controlled Air Suspension (ECAS) active fault.	Red
	CHECK Engine^*	Indicates an engine condition (low oil pressure, low coolant level, high coolant temperature, high DPF soot level, or uncontrolled DPF regeneration) that requires correction. Correct the condition as soon as possible. If the condition worsens, the STOP engine lamp will illuminate.	Amber
	High Exhaust System Temperature (HEST)^*	Slow (10-second) flashing indicates a regeneration (regen) is in progress. IMPORTANT: When the HEST lamp is illuminated, do not park the vehicle near flammable material. Solid illumination indicates high exhaust temperatures at the outlet of the tail pipe when speed is below 5 mph (8 km/h).	Amber
	Diesel Particulate Filter (DPF) Status	Solid illumination indicates a regen is required. Change to a more challenging duty cycle (such as highway driving ) to raise exhaust temperatures for at least twenty minutes, or perform a parked regen. Blinking indicates that a parked regen is required immediately. An engine derate and shutdown will occur.	Amber
	Malfunction Indicator Lamp (MIL)	Indicates an emissions-related fault. See the engine operation manual for details.	Amber
	Vehicle ABS	Momentary illumination indicates the vehicle ABS is engaged. Solid illumination indicates a problem with the vehicle ABS. Repair the ABS immediately to ensure full braking capability.	Amber
	Trailer ABS	Momentary illumination indicates the trailer ABS is engaged. Solid illumination indicates a problem with the trailer ABS. Repair the ABS immediately to ensure full braking capability.	Amber
	No Charge	Indicates the alternator is not properly powering the electrical system.	Amber
	Water in Fuel	Indicates the fuel may contain water. Drain any water collected in the fuel/water separators.	Amber
	Fuel Filter Restriction	Indicates the fuel filter is clogged and requires service.	Amber
	Check Transmission	Indicates an undesirable transmission condition.	Amber
	Start Blocked (GHG14 only)	Indicates that the system is preventing the starter from cranking. This can occur when the ignition switch is turned to START before the gauge sweep has completed. NOTE: Illumination of the Start Blocked lamp does not indicate a problem with the starter. Turn the ignition switch back to ON, wait for the lamp to go out, then turn the ignition switch to START again.	Amber
	Wheel Spin (pre-EPA16)	Flashing indicates the ATC system is active, or the ATC button has been pressed to allow wheel slip. Solid illumination indicates ATC is shut off or unavailable due to a system fault. In the event of a system fault, repair the ATC system immediately to ensure full braking capability.	Amber
	Stability Event (EPA16 and newer)	Flashing indicates a stability event has been detected, and the ESC system is active. Solid illumination indicates a problem with the stability system. Repair the ESC system immediately to ensure full stability capability.	Amber
	ATC Deactivated (EPA16 and newer)	Flashing indicates the ATC SPIN button has been pressed to allow wheel slip. Solid illumination indicates ATC is shut off or unavailable due to a system fault. In the event of a system fault, repair the ATC system immediately to ensure full braking capability.	Amber
	Roll Stability (pre-EPA16)	Momentary illumination indicates that a stability event has occurred. On vehicles that are also equipped with ATC, flashing indicates the ATC button has been pressed to allow wheel slip. Solid illumination indicates ATC is shut off or unavailable due to a system fault. In the event of a system fault, repair the ATC system immediately to ensure full braking capability.	Amber
	Hill Start Aid (HSA) Override	Indicates the HSA switch has been pressed to override the hill start assist feature.	Amber
	Outside Normal Ride Height	Indicates the current rear suspension height is not at the normal ride height. This light will turn off once the vehicle returns to normal ride height.	Amber
	Engine Brake	Indicates the engine brake is enabled.	Green
	Left-Turn Signal	Flashing indicates the outside left-turn signal lights are activated.	Green
	Right-Turn Signal	Flashing indicates the outside right-turn signal lights are activated.	Green
	Cruise Control	Indicates the cruise control is enabled. NOTE: The ICU4Me does not have a green cruise control telltale.	Green
	High-Beam Headlights	Indicates the high-beam headlights are on.	Blue