2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 993
1. Ignition OFF, disconnect the harness connector at the EBCM.
2. Test for less than 1 ohm between the ground circuits listed below and ground.
* Terminal 13
* Terminal 38
瀚慖f greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify that a test lamp illuminates between the B+ circuits listed below and ground.
* Terminal 1
* Terminal 25
瀚慖f the test lamp does not illuminate, test the appropriate circuit for a short to ground or an open/high resistance.
4. If all circuits test normal, replace the EBCM.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
Control Module References (See: Testing and Inspection/Programming and Relearning) for EBCM replacement, setup, and programming
C123D
DTC C056D, C120C, C121C, C121E, C121F, C123A-C1256, C126E-C127C, C12C2-C12DB, C12DE, C12DF, or C12F2-C12F6
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provide an overview of each diagnostic category.
DTC Descriptors
DTC C056D 00
- ECU Hardware Performance
DTC C056D 3C
- ECU Hardware Performance Internal Communications Failure
DTC C056D 59
- ECU Hardware Performance
DTC C120C
- Brake Pedal Position Sensor 4 Plausibility
DTC C121C
- EBCM Internal Communication Error
DTC C121E
- EBCM Unimplemented Interrupt
DTC C121F
- EBCM Unexpected Exception
DTC C123A
- EBCM High End Timer Watchdog
DTC C123B
- EBCM High End Timer Program Overflow
DTC C123C
- EBCM High End Timer RAM Fault
