2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1480

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1480

* 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 P0622

- Generator F-Terminal Circuit

Diagnostic Fault Information

Circuit/System Description

The engine control module (ECM) uses the generator field duty cycle signal circuit, or F-terminal circuit, to monitor the duty cycle of the generator.

The generator field duty cycle signal circuit connects to high side of the field windings in the generator. A pulse width modulated (PWM) high side

driver in the voltage regulator turns the field windings ON and OFF. The ECM uses the PWM signal input to determine the generator load on the

engine. This allows the ECM to adjust the idle speed to compensate for high electrical loads. The ECM monitors the status of the generator field

duty cycle signal circuit. When the ignition is ON and the engine is OFF, the ECM should detect a duty cycle near 0 percent. When the engine is

running, the duty cycle should be between 5-99 percent.

Conditions for Running the DTC

* Ignition ON engine OFF, for the Ignition ON test.

* Engine running, engine speed less than 3,000 RPM for the RUN test.

Conditions for Setting the DTC

* DTC P0621 is not set.

* Ignition ON engine OFF, the ECM detects a PWM signal that is greater than 65 percent for 5 seconds.

* Engine running, the ECM detects a PWM signal that is less than 5 percent for 15 seconds.

Action Taken When the DTC Sets

DTC P0622 is a C type DTC.

Conditions for Clearing the DTC

DTC P0622 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

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)