2010 Cadillac Truck SRX FWD V6-3.0L Page 2052

2010 Cadillac Truck SRX FWD V6-3.0L Page 2052

6. If all circuits test normal, test or replace the B157 secondary air injection pressure sensor.

Repair Instructions

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

* Secondary Injection Shutoff Valve Pressure Sensor Replacement (See: Powertrain Management/Emission Control Systems/Air Injection/Air

Injection Check Valve/Service and Repair)

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

P2500

DTC P2500 or P2501

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 Descriptors

DTC P2500

- Generator L-Terminal Circuit Low Voltage

DTC P2501

- Generator L-Terminal Circuit High Voltage

Diagnostic Fault Information

Circuit/System Description

The engine control module (ECM) uses the generator turn on 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 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. The ECM performs tests to determine the status of the generator turn on control circuit.

Conditions for Running the DTC

P2500

The engine is running.

P2501

* The ignition is ON.

* The engine is OFF.

Conditions for Setting the DTC

P2500

The ECM detects low voltage on the generator turn on control circuit for 2 seconds.

P2501

The ECM detects high voltage on the generator turn on control circuit for 2 seconds.

Action Taken When the DTC Sets