General Information

p3 dm 04.01.001

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).

Cascadia vehicles are equipped with an ICU3, ICU3S, ICU4, ICU4M, or ICU4Me. See Fig., Fig., Fig. and Fig. for typical ICU layouts.

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

  • "Warning and Indicator Lights"

  • "Instruments"

  1. Transmission Temperature Gauge

  2. Coolant Temperature Gauge

  3. Engine Oil Pressure Gauge

  4. Driver Message Center

  5. Fuel/DEF Level Gauge

  6. Primary Air Pressure Gauge

  7. Secondary Air Pressure Gauge

  8. Speedometer

  9. Tachometer

  10. High Beam Indicator

  11. Driver Display Screen

  12. Mode/Reset Switch

  13. Satellite Gauges

Fig. 1, ICU3 Instrument Cluster (EPA10 shown)

Note:  This instrument cluster has 8 optional telltales. The gear, engine brake, and cruise control are indicated in the driver display, rather than with telltales.

  1. Engine Oil Pressure Gauge

  2. Optional Telltales

  3. Driver Message Center

  4. Fuel/DEF Level Gauge

  5. Primary Air Pressure Gauge

  6. Secondary Air Pressure Gauge

  7. Speedometer (U.S. version)

  8. Tachometer

  9. Transmission Temperature Gauge

  10. Coolant Temperature Gauge

Fig. 2, ICU3S (GHG14 and newer shown)

Note: The ICU4 and ICU4M are nearly identical, with the exception of the driver message center (Item 7).

  1. Battery Voltage Gauge

  2. Lightbar

  3. Engine Oil Pressure Gauge

  4. Coolant Temperature Gauge

  5. Engine Oil Temperature Gauge

  6. Turbo Boost Air Pressure Gauge

  7. Driver Message Center

  8. Tachometer

  9. Speedometer

  10. Primary Air Pressure Gauge

  11. Fuel/DEF Level Gauge

  12. Secondary Air Pressure Gauge

  13. Pyrometer

  14. Rear Axle Temperature Gauge

Fig. 3, ICU4M Instrument Cluster (EPA10 shown)

  1. Engine Oil Temperature Gauge

  2. Front Axle Temperature Gauge

  3. Rear Axle Temperature Gauge

  4. Speedometer and Coolant Temperature Gauge

  5. Fuel/DEF Level Gauge

  6. Tachometer and Engine Oil Pressure Gauge

  7. Primary Air Pressure Gauge

  8. Secondary Air Pressure Gauge

  9. Transmission Oil Temperature Gauge

  10. Driver Message Center

Fig. 4, ICU4Me Instrument Cluster

"Driver Message Center"

Note:
Parent topic: Instrumentation Control Units
Document Number: 0000116688
Manual Publication Date: 2025-02-11
Topic Publication Date: 2024-05-06