The Instrumentation Control Unit (ICU) and Fault Codes
Note: Some non-critical faults may be suppressed and will not appear during an instrumentation control unit (ICU) self-check.
The majority of electrical and electronic issues on the vehicle will have an associated fault code, which will be displayed on the ICU.
If the ICU receives active fault codes during the ICU self-check, 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 alerts until acknowledged. See Fig.. If there are no active faults, the ICU displays the home screen after the self-check completes.
Fig. 1, ICUC Active Faults Alert Screen
When there is an active vehicle fault code, a popup will appear on the ICU message screen.
To access fault codes in the ICU:
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Use the buttons on the left-hand steering wheel to navigate to the wrench icon and press OK.
Fig. 2, Electronic Control Unite (ECU) List in the ICUC
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ECU’s with active faults will have an exclamation point next to them. Use the down arrow to select the affected ECU from the list, then press OK.
Refer to the ECU acronyms list for the full names of acronyms on the ICU screen. See Table..
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Locate the code to troubleshoot from the list of active fault codes, then press OK to access the information screen. See Fig..
Fig. 3, Information Screen for an Active Fault Code
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Press OK again to access additional information. See Fig..
Fig. 4, Additional Information for the Fault
Table 1, ICU Electronic Control Unit Acronyms
ICU Electronic Control Unit Acronyms
ABS
Antilock Brake System
ICU
Instrumentation Control Unit
ACM
Aftertreatment Control Module
MCM
Motor Control Module
CGW
Central Gateway
RDF
Radar Front End
CPC
Common Powertrain Controller
SAS
Steering Angle Sensor
DCMD
Door Control Module, Driver
SSAM
Single Signal Detect and Actuation Module
DCMP
Door Control Module, Passenger
TCM
Transmission Control Module
HVCF
Heating/Ventilation/AC Front (HVAC)
TPMS
Tire Pressure Monitoring System
HVCP
Heating/Ventilation/AC, Auxiliary (HVAC)
VRDU
Video Radar Decision Unit
Table 1, ICU Electronic Control Unit Acronyms