2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2743
when the fault occurs.
Reference Information
Schematic Reference
* Data Communication Schematics (See: Powertrain Management/Computers and Control Systems/Information Bus/Diagrams/Electrical
Diagrams)
* Control Module References (See: Testing and Inspection/Programming and Relearning)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Data Link Communications Description and Operation (See: Powertrain Management/Computers and Control Systems/Information
Bus/Description and Operation)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit
Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General
Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring
Repairs/Wiring Repairs)
Circuit/System Verification
1. Verify that DTC B137B or U189A are not present in the SDGM.
瀚慖f any listed DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code
Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle) to diagnose that DTC prior to this diagnostic.
2. Verify the DTC U0074 is not set.
瀚慖f DTC U0074 is set as a current or history code, refer to DTC U0074 (See: U Code Charts/U0074).
Circuit/System Testing
1. Ignition OFF, test for less than 1.0 ohm between the accessory DC power control module case and ground strap.
瀚慖f greater than the specified value, test the ground circuit for an open/high resistance.
2. Disconnect harness connector X3 of the accessory DC power control module.
3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal A and ground.
瀚慖f the test lamp does not illuminate, test the B+ circuit for an open/high resistance. If the circuit fuse is open, test the control circuits of the
accessory DC power control module for a short to ground.
4. Ignition OFF, disconnect harness connector X1 of the accessory DC power control module.
5. Ignition ON, verify that a test lamp illuminates between the wake up signal circuit terminal 3 and ground.
瀚慖f the test lamp does not illuminate, test the wake up signal circuit for an open/high resistance or a short to ground. If the circuit tests
normal, replace the serial data gateway module.
6. If all circuits test normal, replace the accessory DC power control module.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* GMLAN Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Wiring Repairs/GMLAN Wiring Repairs)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for control module replacement, setup, and
