2010 Cadillac Truck Escalade RWD V8-6.2L Page 2883
Circuit/System Description
The body control module (BCM) applies voltage to the high speed GMLAN serial data wake up circuit, when the ignition key is in ACC, ON or
START to enable several modules for bus communication.
Depending on option content, modules that may receive the signal are as follows:
* Drive motor generator battery control module (BECM) (RPO HP2)
* Electronic brake control module (EBCM)
* Electronic suspension control (ESC) module
* Fuel pump flow control module (FPCM)
* Power steering control module (PSCM) (RPO HP2)
Conditions for Running the DTC
* The system voltage is between 9-16 volts.
* The BCM attempts to enable the modules connected to the high speed GMLAN serial data wake up circuit.
Conditions for Setting the DTC
The BCM senses a short to ground on the high speed GMLAN serial data wake up circuit.
Action Taken When the DTC Sets
* The output command is turned off while the malfunction is present.
* The modules use a default value for the missing parameters.
* The module(s) is never signaled, therefore the specific subsystem(s) will not function.
* The vehicle will not start while the circuit is shorted to ground.
Conditions for Clearing the DTC
* A current DTC clears when the malfunction is no longer present.
* A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.
Diagnostic Aids
Short to ground will also set multiple history no communication codes for GMLAN high speed modules
Reference Information
Schematic Reference
* Body Control System Schematics (See: Body and Frame/Body Control Systems/Diagrams/Electrical Diagrams)
* Data Communication Schematics (See: Powertrain Management/Computers and Control Systems/Information Bus/Diagrams/Electrical
Diagrams)
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)
