Diagnostic Instructions
| • | 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. |
DTC Descriptor
DTC B3794 08: Cruise Control Function Request Circuit Signal InvalidDiagnostic Fault Information
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
|---|---|---|---|---|---|
B+ | 1 | B3794 08 | 1 | 1 | B3794 08 |
Cruise Control Switch Signal | 1 | B3794 08 | 1 | B3794 08 | B3794 08 |
Ground | -- | 1 | 1 | -- | -- |
1. Cruise Control Malfunction | |||||
Circuit/System Description
The cruise control switch is an input to the body control module (BCM). The BCM monitors the cruise control Set/Coast and Resume/Accelerate 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 BCM sends a serial data message to the engine control module (ECM), indicating the status of the cruise control switches.
Conditions for Running the DTC
| • | The ignition is ON. |
| • | The cruise switch is ON. |
Conditions for Setting the DTC
| • | The BCM detects an invalid voltage signal on the cruise control switch signal circuit. |
| • | The above condition is present for greater than 1 second. |
Actions Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The cruise control system is disabled. |
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists. |
| • | A history DTC will clear after 40 malfunction-free ignition cycles have occurred. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Cruise Control Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Engine ON, observe the scan tool Cruise Control Switch parameter while pressing each of the cruise control switches. The parameter should toggle between On, Off, Resume and Set as the applicable switch is pressed.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the steering wheel controls switch - left.
- Ignition OFF, test for less than 10 ohms between the ground circuit terminal 7 and ground.
- Ignition ON, test for B+ between the B+ circuit terminal 4 and ground.
- Test for B+ between the B+ circuit terminal 4 and the signal circuit terminal 5.
- Ignition OFF, disconnect the X2 harness connector at the BCM.
- Test for infinite resistance between the signal circuit terminal 5 and ground.
- If all circuits test normal, test or replace the steering wheel control switch - left.
| ⇒ | If greater than the specified value, test the ground circuit for an open/high resistance. |
| ⇒ | If less than the specified value, test the circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
| ⇒ | If less than the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM. |
| ⇒ | If less than the specified value, test the signal circuit for a short to ground. |
Component Testing
- Disconnect the harness connector at the steering wheel controls switch - left.
- Cruise control switch ON, measure the resistance between terminal 4 and terminal 5 while individually activating and holding each cruise control function switch and compare the resistance reading to the values in the table below.
| ⇒ | If not within the specified resistance range, replace the steering wheel controls switch - left. |
Function Switch | Minimum Resistance Value | Maximum Resistance Value |
|---|---|---|
Off | O.L. | O.L. |
On | 0.0 Ohms | 0.5 Ohms |
- SET | 1.4k Ohms | 1.6k Ohms |
+ RES | 4.3k Ohms | 4.5k Ohms |
neutral position | 8.0k Ohms | 8.5k Ohms |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
