• | 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. |
The instrument panel cluster (IPC) illuminates the cruise control engaged indicator based on serial data messages received from the engine control module (ECM). The indicator is commanded ON when the cruise control system is controlling vehicle speed, and turned OFF with the system disengaged.
Control Module References for scan tool information
Ignition ON, with a scan tool perform the Lamp Test for the instrument panel cluster (IPC) and observe the cruise control indicator.
⇒ | If the cruise control indicator illuminates during the test, replace the ECM. |
⇒ | If the cruise control indicator does not illuminates during the test or remains illuminated at all times, replace the IPC. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for ECM or IPC replacement, setup, and programming
• | 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. |
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
B+ Voltage Reference | 1 | B3794 08, B3794 6 | 1 | 1 | B3794 08, B3794 61 |
Cruise Control Switch Signal | 1 | B3794 08, B3794 6 | 1 | B3794 08 | B3794 08, B3794 61 |
Cruise Control Switch Indicator Signal | -- | 2 | 2 | -- | -- |
1. Cruise Control Malfunction 2. Cruise Control Indicator Malfunction |
The cruise control switch contains an LED that illuminates to indicate the cruise control system has been switched ON. Voltage is applied through the ON/OFF switch to the LED when the switch is pressed. The BCM provides the ground path for the LED through a dedicated control circuit. Pressing the switch again opens the switch and the lamp turns OFF.
Control Module References for scan tool information
Ignition ON, observe the cruise control indicator while applying the cruise On/Off switch. The indicator should turn on and off accordingly with the applied switch.
Important: Refer to DTC B3794 before performing this diagnostic, if this code is set as current or history.
⇒ | If the test lamp does not illuminate, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM replacement, setup, and programming |