2010 Cadillac CTS Sedan AWD V6-3.0L Page 1487

2010 Cadillac CTS Sedan AWD V6-3.0L Page 1487

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code

(DTC) Type Definitions)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning)for scan tool information

Circuit/System Verification

1. Engine running, accessories OFF, measure and record the battery voltage at the battery terminals. The voltage should be between 12.6 and

15.0 V.

瀚慖f not within the specified range, refer to Charging System Test (See: Starting and Charging/Testing and Inspection/Component Tests

and General Diagnostics/Charging System Test).

2. Engine running, observe the scan tool of the appropriate control module battery voltage parameters. Verify that the scan tool displays a value

that is within 2 V of the battery terminal voltage.

瀚慖f not within the specified range, replace the appropriate control module.

Repair Instructions

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

Control Module References (See: Testing and Inspection/Programming and Relearning)for the appropriate control module replacement, setup, and

programming

P0571

DTC P0571

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 P0571

- Cruise Control Brake Switch Circuit

Diagnostic Fault Information

Circuit/System Description

The brake applied signal circuit is a high voltage input from the body control module (BCM) to the engine control module (ECM) and transmission

control module (TCM). The ECM monitors the stop lamp switch circuit to detect when the brake pedal has been applied. The BCM monitors the

brake pedal position sensor to determine when the brake pedal is applied. When the brake pedal is applied, the BCM supplies a high voltage signal

on the brake applied signal circuit and also sends a serial data message to the ECM indicating that the brake pedal has been applied. The ECM

senses a high voltage signal on the brake applied signal circuit when the brake pedal has been applied.

Conditions for Running the DTC

* The engine is running.

* Battery voltage is greater than 11.5 V.

Conditions for Setting the DTC

The ECM detects either a low voltage signal on the brake applied signal circuit when the serial data message from the BCM indicates the brakes are

applied, or a high voltage signal on the brake applied signal circuit when the serial data message from the BCM indicates the brakes are not applied.

Actions Taken When the DTC Sets