B3794

DTC B3794

Diagnostic Instructions
^ Perform the [Diagnostic System Check - Vehicle Diagnostic Information] prior to using this diagnostic procedure. Diagnostic System Check - Vehicle Diagnostic Information
^ Review [Strategy Based Diagnosis] for an overview of the diagnostic approach. Strategy Based Diagnosis
^ [Diagnostic Procedure Instructions - Vehicle Diagnostic Information] provides an overview of each diagnostic category. Diagnostic Procedure Instructions - Vehicle Diagnostic Information

DTC Descriptor
DTC B3794 08 Cruise Control Function Request Circuit Signal Invalid
DTC B3794 61 Cruise Control Function Request Circuit Actuator Stuck

Diagnostic Fault Information






Circuit/System Description
The cruise control switch is an input to the body control module (BCM). The BCM monitors the cruise control on/off, set/coast, resume/accelerate, and cancel switches via 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.

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 0.5 second.

Action Taken When the DTC Sets
^ 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.

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 40 malfunction-free warm-up cycles.

Circuit/System Verification
Ignition ON, observe the scan tool Cruise Control Switch parameter while pressing the cruise control switches. The reading should change between On, Off, Resume, Set and Cancel accordingly with the depressed switches.

Circuit/System Testing
1. Ignition OFF, remove the inflatable restraint steering wheel module.
2. Disconnect the harness connector at the steering wheel controls switch - left.
3. Ignition ON, test for greater than 10 volts between the supply voltage circuit terminal 1 and ground.
^ If less than the specified range, test the supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

4. Verify the scan tool Cruise Control Switch parameter is OFF.
^ If not the specified value, test the signal circuit terminal 3 for a short to voltage. If the circuit tests normal, replace the BCM.

5. Ignition OFF, connect the harness connector at the steering wheel controls switch - left.
6. Ignition ON, with the cruise control switch in the ON position, observe the scan tool Cruise Control Switch parameter. The parameter should display ON.
^ If not the specified value, test the signal circuit terminal 3 for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the steering wheel controls switch - left.

7. Observe the scan tool Cruise Control Switch parameter while pressing the RES + portion of the cruise control switch. The parameter should display Resume.
^ If not the specified value, test or replace the steering wheel controls switch - left.

8. Observe the scan tool Cruise Control Switch parameter while pressing the SET - portion of the cruise control switch. The parameter should display Set.
^ If not the specified value, test or replace the steering wheel controls switch - left.

9. Observe the scan tool Cruise Control Switch parameter while pressing the Cancel portion of the cruise control switch. The parameter should display Cancel.
^ If not the specified value, test or replace the steering wheel controls switch - left.

10. If the circuits test normal, test or replace the BCM.

Component Testing

NOTE: The cruise control ON/OFF switch must be ON in order to properly measure the resistance of the - SET, the + RES, and the Cancel switches.

Steering Wheel Controls Switch - Left
1. Ignition OFF, remove the inflatable restraint steering wheel module.
2. Ignition OFF, disconnect the steering wheel controls switch - left.
3. Cruise switch ON, measure the resistance between terminals 1 and 3 at the cruise control switch side of the connector. Individually activate and hold each cruise control function switch and compare the resistance reading to the values on the schematic for the ON/OFF, SET -, the RES +, and the Cancel 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 switch - left.






Repair Instructions
Perform the [Diagnostic Repair Verification - Vehicle Diagnostic Information] after completing the diagnostic procedure. Diagnostic Repair Verification - Vehicle Diagnostic Information
^ [Steering Wheel Control Switch Assembly Replacement]