Diagnostic Instructions
DTC Descriptor
DTC P0575: Cruise Control Switch Signal Circuit
Circuit/System Description
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.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
| • | The ECM receives an invalid cruise control switch status GMLAN serial data message from the BCM. |
| • | This diagnostic runs continuously. |
Action Taken When the DTC Sets
| • | 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. |
Conditions for Clearing the DTC
| • | The DTC becomes history when the conditions for setting the DTC are no longer present. |
| • | The history DTC clears after 50 consecutive warm-up cycles. |
| • | The ECM receives a clear code command from the scan tool |
Diagnostic Aids
Using the Failure Records data may help locate an intermittent condition. If you cannot duplicate the DTC, the information in the Failure Records can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can help determine
how many ignition cycles that the diagnostic test reported a pass and/or a fail.
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
Scan Tool Reference
Scan Tool Data List
Circuit/System Verification
Important: Verify that B3794 is not set as current or history before performing this diagnostic. If B3794 is set as current or history, go to
DTC B3794.
Ignition ON, observe the scan tool Cruise Control Switch parameter in the BCM while pressing the cruise control switch ON and OFF. The reading should change between ON and OFF.
| ⇒ | If the parameter does not switch between ON and OFF, replace the BCM. |
Circuit/System Testing
Ignition ON, verify that DTC P0575 is current in the ECM.
| ⇒ | If the DTC is stored as a current DTC, replace the BCM. |
| ⇒ | If the DTC is stored only as a history DTC, refer to Diagnostic Aids. Do not replace the BCM. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for BCM replacement, setup, and programming
