2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2191

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2191

DTC Descriptor

DTC P0621

- Generator L-Terminal Circuit

Diagnostic Fault Information

Circuit/System Description

The engine control module (ECM) uses the charge indicator control circuit, or L-terminal circuit, to control the load of the generator on the engine.

A high side driver in the ECM applies a voltage to the voltage regulator. This signals the voltage regulator to turn the field circuit ON and OFF.

The ECM monitors the state of the charge indicator control circuit.

Conditions for Running the DTC

* The engine is running.

* No generator, CKP sensors, CMP sensor DTCs are set.

Conditions for Setting the DTC

The charge indicator control circuit is shorted to ground or shorted to voltage for 20 seconds.

Action Taken When the DTC Sets

* The charge indicator turns ON.

* The driver information center (DIC) displays the SERVICE BATTERY CHARGING SYSTEM message.

Conditions for Clearing the DTC

* The DTC will pass when the condition for setting the DTC is no longer present for 2 seconds.

* A history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.

* The charge indicator and DIC message will remain ON until the DTC passes or is cleared, even if the ignition is cycled.

Reference Information

Schematic Reference

Starting and Charging Schematics (See: Starting and Charging/Diagrams/Electrical Diagrams)

Connector End View Reference

Component Connector End Views (See: Diagrams/Connector Views)

Description and Operation

Charging System Description and Operation (See: Starting and Charging/Charging System/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. Verify that a test lamp illuminates between the G13 generator B+ terminal 1 X2 and ground.

瀚慖f the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.