• | 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 provide an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Cruise Control Switch Supply Voltage | 1 | B3794 08 | -- | B3794 08 |
Cruise Control Switch Signal | B3794 08 | B3794 08 | 1 | B3794 08 |
1. Cruise Control Inoperative/Malfunctioning |
The cruise control switch is an input to the body control module (BCM). The BCM monitors the cruise control switch signal circuit in order to detect when the driver has requested to perform a cruise control function. The BCM detects a specific voltage signal on the cruise control switch signal circuit when a switch is applied.
• | The ignition is ON. |
• | The cruise switch is ON. |
• | The BCM detects an invalid voltage signal on the cruise control switch signal circuit. |
• | The above condition is present for 0.5 second. |
• | The BCM stores the DTC information into memory when the diagnostic runs and fails. |
• | The malfunction indicator lamp (MIL) will not illuminate. |
• | The cruise control system is disabled. |
• | The DTC becomes history when the conditions for setting the DTC are no longer present. |
• | The history DTC clears after 40 malfunction-free warm-up cycles. |
Cruise Control Description and Operation
Engine ON, observe the scan tool Cruise Control Switch parameter in the BCM while pressing the various cruise control switches. The reading should be toggle between On, Off, Resume and Set accordingly with the depressed switches.
⇒ | If less than the specified value, test the cruise control switch supply voltage circuit for a short to ground or an open/high resistance. |
⇒ | If greater than the specified range, test the cruise control switch signal circuit for an open/high resistance. |
⇒ | If less than the specified value, test the cruise control switch signal circuit for a short to ground. |
⇒ | If the test lamp illuminates, test the cruise control switch signal circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
Important: The cruise control ON/OFF switch must be ON in order to properly measure the resistance of the ON, SET - , and the RES + switches.
⇒ | If any of the resistance measurements for the OFF, ON, - SET, + RES, and Cancel switches are not within the listed resistance values, replace the steering wheel controls - left switch assembly. |
Function Switch | Minimum Resistance Value | Maximum Resistance Value |
---|---|---|
OFF | O.L. | O.L. |
ON | 8.1k ohms | 8.4k ohms |
SET - | 1.2k ohms | 1.4k ohms |
RES + | 2.8k ohms | 3.0k ohms |
Cancel | 0.0k ohms | 0.3k ohms |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM 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 provide an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Cruise Control Switch Supply Voltage | 1 | B3794 08 | -- | B3794 08 |
Cruise Control Switch Signal | B3794 08 | B3794 08 | 1 | B3794 08 |
1. Cruise Control Inoperative/Malfunctioning |
The cruise control switch is an input to the body control module (BCM). The BCM monitors the cruise control switch signal circuit in order to detect when the driver has requested to perform a cruise control function. The BCM detects a specific voltage signal on the cruise control switch signal circuit when a switch is applied.
• | The ignition is ON. |
• | The cruise switch is ON. |
• | The BCM detects an invalid voltage signal on the cruise control switch signal circuit. |
• | The above condition is present for 0.5 second. |
• | The BCM stores the DTC information into memory when the diagnostic runs and fails. |
• | The malfunction indicator lamp (MIL) will not illuminate. |
• | The cruise control system is disabled. |
• | The DTC becomes history when the conditions for setting the DTC are no longer present. |
• | The history DTC clears after 40 malfunction-free warm-up cycles. |
Cruise Control Description and Operation
Engine ON, observe the scan tool Cruise Control Switch parameter in the BCM while pressing the various cruise control switches. The reading should be toggle between On, Off, Resume and Set accordingly with the depressed switches.
⇒ | If less than the specified value, test the cruise control switch supply voltage circuit for a short to ground or an open/high resistance. |
⇒ | If less than the specified value, test the cruise control switch supply voltage circuit for a short to ground or an open/high resistance between the steering wheel controls switch - left and the steering wheel controls switch - right. |
⇒ | If greater than the specified range, test the cruise control switch signal circuit for an open/high resistance. |
⇒ | If less than the specified value, test the cruise control switch signal circuit for a short to ground. |
⇒ | If the test lamp illuminates, test the cruise control switch signal circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
⇒ | If the resistance measurements for the ON and OFF switch are not within the listed resistance values, replace the steering wheel controls - left switch assembly. |
⇒ | If any of the resistance measurements for the - SET, + RES, and the default value are not within the listed resistance values, replace the steering wheel controls - right switch assembly. |
Function Switch | Minimum Resistance Value | Maximum Resistance Value |
---|---|---|
OFF | O.L. | O.L. |
ON | 0.0k ohms | 0.5 ohms |
SET - | 1.4k ohms | 1.6k ohms |
RES + | 4.3k ohms | 4.5k ohms |
Steering Wheel Controls - Right default | 8.1k ohms | 8.5k ohms |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM replacement, setup, and programming |