2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 470
Circuit/System Description
The body control module (BCM) controls the Run/Crank relay through the run/crank relay coil control circuit by applying voltage to the circuit.
The Run/Crank relay is energized when the ignition switch is in ON or START, or when a remote start is requested.
Conditions for Running the DTC
* The system voltage is between 9-16 volts.
* The DTC can only run when the output is activated.
Conditions for Setting the DTC
The BCM detects a short to ground in the run/crank relay coil control circuit.
Action Taken When the DTC Sets
The module output driver will be shut down and not supply voltage to the run/crank relay coil control circuit.
Conditions for Clearing the DTC
* The current DTC will clear when the module request for the output is removed or 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 voltage in the run/crank relay coil control circuit will cause the malfunction indicator lamp (MIL) to illuminate with the ignition key OFF,
and the engine will remain running if started and the ignition key is removed.
Reference Information
Schematic Reference
* Body Control System Schematics (See: Body and Frame/Body Control Systems/Diagrams/Electrical Diagrams)
* Power Distribution Schematics (See: Diagrams/Electrical Diagrams/Starting and Charging/Power and Ground Distribution/System
Diagram/Power Distribution Schematics)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Power Mode Description and Operation (See: Power and Ground Distribution/Description and Operation/Power Mode 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)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Testing
1. Ignition OFF, disconnect the Run/Crank relay.
2. Connect a test lamp between the relay coil control circuit terminal 86 and ground.
3. Cycle the ignition ON and OFF. The test lamp should turn ON and OFF when changing ignition switch positions.
瀚慖f the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
