| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. | 
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. | 
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. | 
When a cruise control function switch is activated, the body control module (BCM) detects a predetermined voltage signal. The BCM sends a serial data message to the engine control module (ECM) indicating the function that has been requested.
The ignition is ON.
| • | The ECM receives an invalid cruise control switch status serial data message from the BCM. | 
| • | This diagnostic runs continuously. | 
| • | The malfunction indicator lamp (MIL) will not illuminate. | 
| • | The cruise control system is disabled. | 
| • | The condition responsible for setting the DTC not longer exists. | 
| • | A history DTC will clear after 40 malfunction-free ignition cycles have occurred. | 
Cruise Control Description and Operation
Control Module References for scan tool information
| ⇒ | If DTC is set, refer to DTC B3794 | 
| ⇒ | If DTC resets, replace the BCM. Clear the DTC, road test the vehicle and attempt to engage cruise. If the DTC resets, replace the ECM. | 
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for BCM or ECM replacement, setup, and programming.