When a cruise control function switch is activated, the body control module (BCM) detects a predetermined voltage signal. The BCM sends a GMLAN serial data message to the engine control module (ECM) indicating the function that has been requested.
This diagnostic procedure supports the following DTC:
DTC P0575 Cruise Control Switch Signal Circuit
The engine is ON.
• | The ECM receives an invalid cruise control switch status GMLAN serial data message from the BCM. |
• | This diagnostic runs continuously. |
• | The Cruise Control System is disabled. |
• | The ECM stores the DTC information into memory when the diagnostic runs and fails. |
• | The malfunction indicator lamp (MIL) will not illuminate. |
• | The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Failure Records. |
• | All cruise control function switches are set to OFF. |
• | A last test failed, or the current DTC, clears when the diagnostic runs and does not fail. |
• | A history DTC clears after 40 consecutive warm-up cycles, if failures are not reported by this or any other emission related diagnostic. |
• | Use the scan tool in order to clear the DTC. |
• | This DTC may be stored as a history DTC without affecting the operation of the BCM. If stored only as a history DTC and not retrieved as a current DTC, do not replace the BCM. |
• | If this DTC is retrieved as both a current and history DTC, replace the BCM. |
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: Cruise Control Schematics Connector End View Reference: Computer/Integrating Systems Connector End Views | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 | Is DTC P0575 current in the engine control module (ECM)? | Go to Step 3 | Go to Diagnostic Aids |
3 | Replace the body control module (BCM). Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 4 | -- |
4 |
Does the DTC reset? | Go to Step 2 | System OK |