Circuit Description
The body control module (BCM) receives a signal from the brake pedal position sensor through the stop lamp switch signal circuit. The BCM then applies voltage through the stop lamp voltage supply circuit to the PCM, EBCM and the stop lamps.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0572 Cruise Control Brake Switch Circuit Low Voltage
Conditions for Running the DTC
| • | Vehicle has cycled from 0-60 km/h (0-37 mph) 3 times in 1 ignition cycle. |
| • | Continuous once the previous criteria have been met. |
Conditions for Setting the DTC
The PCM detects an open or short to ground on the stop lamp voltage supply circuit when the voltage should be present.
Action Taken When the DTC Sets
| • | The PCM stores the DTC information into memory when the diagnostic runs and fails. |
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records. |
Conditions for Clearing the DTC
| • | A last test failed, or current DTC, clears when the diagnostic runs and does not fail. |
| • | A history DTC will clear after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic. |
| • | Use a scan tool in order to clear the DTC. |
Diagnostic Aids
Important:
• Verify that the brake pedal position sensor switch is adjusted properly. Refer to
Brake Pedal Position Sensor Calibration
. • Test drive the vehicle if a switch or circuit condition cannot be located. An intermittent condition may be duplicated during a test drive. • For an intermittent, refer to
Testing for Intermittent Conditions and Poor Connections
.
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Exterior Lights Schematics Connector End View Reference: Master Electrical Component List | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
Does the stop lamp signal parameter indicate OFF? | Go to Step 3 | Go to Diagnostic Aids | |
3 | Test for a short to ground, an open or a poor connection in the stop lamp voltage supply circuit. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 5 | Go to Step 4 |
4 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 5 | -- |
5 |
Does the DTC reset? | Go to Step 2 | System OK |
