2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2192

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2192

2. Ignition OFF, disconnect the X1 harness connector at the generator.

3. Ignition ON, test for 4.5-5.5 V between the control circuit terminal 1 and ground.

瀚慖f greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.

瀚慖f less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace

the ECM.

4. If all circuits test normal, test or replace the generator.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

* Generator Replacement (See: Starting and Charging/Charging System/Alternator/Service and Repair/Generator Replacement)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup, and programming

P0622

DTC P0622

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 P0622

- Generator F-Terminal Circuit

Diagnostic Fault Information

Typical Scan Tool Data

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

* The ignition is ON.

* The engine speed is less than 3000 RPM.

* No generator, crankshaft, or camshaft position sensor DTCs are set.