2010 Cadillac Truck SRX FWD V6-3.0L Page 1572
Control Module References (See: Testing and Inspection/Programming and Relearning)for BCM or ECM, replacement, setup, and programming
P0573
DTC P0572 or P0573
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 P0572
- Brake Switch Circuit 1 Low Voltage
DTC P0573
- Brake Switch Circuit 1 High Voltage
Diagnostic Fault Information
Circuit/System Description
The stop lamp switch signal circuit is a B+ input from the body control module (BCM) to the engine control module (ECM). 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 B+ on the stop lamp switch signal circuit and also sends a serial data
message to the ECM indicating that 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
P0572
This DTC will set when the ECM detects a short to ground or an open on the discrete brake signal circuit when the serial data message from the
BCM indicates the brakes are applied. This diagnostic will run when the serial data message and the voltage signal on the brake switch signal
circuit do not match for 8 out 10 times, and the condition is present for greater than 2 seconds.
P0573
This DTC will set when the ECM detects a short to voltage on the discrete brake signal circuit when the serial data message from the BCM
indicates the brakes are NOT applied. This diagnostic will run when the serial data message and the voltage signal on the brake switch signal circuit
do not match for 8 out 10 times, and the condition is present for greater than 2 seconds.
Actions Taken When the DTC Sets
* The malfunction indicator lamp (MIL) will not illuminate.
* The cruise control system is disabled.
Conditions for Clearing the DTC
* The condition responsible for setting the DTC no longer exists.
* A history DTC will clear after 40 malfunction-free ignition cycles have occurred.
Reference Information
Schematic Reference
Cruise Control Schematics (See: Cruise Control/Diagrams/Electrical Diagrams)
