2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 2867
* Circuits to the HPCM are diagnosed only to the PIM connector because the HPCM is replaced as part of the PIM.
* Different DTCs may set in different modules along with this DTC depending on where the fault occurs and the vehicle operating conditions
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
With a scan tool, ensure the following DTCs are not present in the modules as follows:
* BCM - U1814
* HPCM - U1812
* SDGM - B137A or U209A
If 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.
Circuit/System Testing
1. Ignition OFF, disconnect harness connector X1 of the APM.
2. Test for less than 0.5 volts between the wake up signal circuit terminal 3 and ground.
瀚慖f greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the SDGM.
3. Disconnect harness connector X1 of the PIM.
4. Test for B+ between the wake up signal circuit terminal 19 and ground.
瀚慖f less than the specified value, test the circuit for an open/high resistance. If the circuit tests normal, replace the SDGM.
5. Test for less than 1.0 ohm between the APM and the PIM on the following circuit terminals.
* PTLAN + APM terminal 2 and PIM terminal 25
* PTLAN - APM terminal 1 and PIM terminal 24
瀚慖f greater than the specified range, test the circuit for an open/high resistance.
6. Ignition OFF, disconnect harness connector X3 of the engine control module (ECM).
7. Test for less than 1.0 ohm between the APM and the ECM on the following circuit terminals.
* PTLAN + APM terminal 11 and ECM terminal 53
* PTLAN - APM terminal 10 and ECM terminal 33
瀚慖f greater than the specified range, test the circuit for an open/high resistance.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
