2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1478
* Relay Replacement (Attached to Wire Harness) (See: Power and Ground Distribution/Power Distribution Relay/Service and Repair/Relay
Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (See: Power and Ground Distribution/Power
Distribution Relay/Service and Repair/Relay Replacement (Within an Electrical Center))
* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup, and programming
P0621
DTC P0621
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptor
DTC P0621
- Generator L-Terminal Circuit
Diagnostic Fault Information
Circuit/System Description
The engine control module (ECM) uses the generator turn ON control 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 controls the voltage regulator to turn the field circuit ON and OFF. The ECM monitors
the state of the generator turn ON control circuit. The ECM should detect low voltage on generator turn on control circuit when the ignition is ON
and the engine is OFF, or when the charging system malfunctions. With the engine running, the ECM should detect high voltage on the generator
turn on control circuit.
Conditions for Running the DTC
* The ignition ON, engine OFF for ignition on test.
* The engine is running for the run test.
Conditions for Setting the DTC
* During the ignition on test, the ECM detects voltage on the generator turn on control circuit for 5 seconds.
* During the run test, the ECM detects low voltage on the generator turn on control circuit for 15 seconds.
Action Taken When the DTC Sets
DTC P0621 is a C type DTC.
Conditions for Clearing the DTC
DTC P0621 is a C type DTC.
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/Connector End Views By Name)
Description and Operation
