Ignition Sequence

57x dm 03.01.002

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.

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

ICUC

Note: Air gauges in the ICUC do not complete a sweep of their dials during the ignition sequence.

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

  • If equipped, the Detroit Assurance splash screen appears.

  • The Western Star logo, engine, and transmission information display and remain until startup is complete

  • Speedometer and tachometer complete a full sweep of their dials

  • Warning and indicator lamps illuminate, then are extinguished (if not active)

  • Audible alert sounds for any active faults

  • Active alerts are displayed on the ICUC screen.

If the ICUC receives active fault codes, it displays them one after the other until the ignition is turned off. The alerts are displayed until they are acknowledged. If there are no active faults, the ICUC displays the home screen after the self-check completes.

Note: If any red or amber warning and indicator lamps do not illuminate during the ICUC self-check or do not go out (if not active) after the self-check completes, take the vehicle to an authorized Western Star service facility as soon as possible.

If active faults are present, take the action outlined in ‘Warnings, Indicators, and Messages’ tables in this chapter, then take the vehicle to an authorized Western Star service facility as soon as possible.

Note:
Parent topic: Instrumentation Control Unit
Document Number: 0000107827
Manual Publication Date: 2024-05-09
Topic Publication Date: 2025-12-18