For 1990-2009 cars

### 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 Descriptors

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

### Diagnostic Fault Information

Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance
--- | --- | --- | --- | --- | ---
B+ Voltage Reference | 1 | B3794 08 | 1 | 1 | B3794 08, B3794 61
Cruise Control Switch Signal | 1 | B3794 08 | 1 | B3794 61 | B3794 08, B3794 61
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 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. 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 cruise switch is ON.

• | The ignition is ON.

### Conditions for Setting the DTC

#### B3794 08

The BCM detects an invalid voltage signal on the cruise control switch signal circuit is present for 0.5 second.

#### B3794 61

Stuck switch for either Resume/Accel. or Set/Coast button for 60 seconds.

### 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

Cruise Control Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Cruise Control Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

Engine ON, while rotating the steering wheel to both steering stops, observe the scan tool Cruise Control Switch parameter while pressing each of the cruise control switches. The parameter should toggle between ON, OFF, Resume, Set, and Cancel as the applicable switch is pressed.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the steering wheel controls switch - left.
2. Ignition ON, test for B+ between the voltage reference circuit terminal 1 and ground.

⇒ | If less than the specified value, test the voltage reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

3. Test for B+ between the voltage reference circuit terminal 1 and the signal circuit terminal 3.

⇒ | 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.

4. Ignition OFF, disconnect the X1 harness connector at the BCM.
5. Test for infinite resistance between the signal circuit terminal 3 and ground.

⇒ | If less than the specified value, test the signal circuit for a short to ground.

6. If all circuits test normal, test or replace the steering wheel control switch-left.

### Component Testing

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

1. Ignition OFF, disconnect the harness connector at the steering wheel controls switch - left.
2. 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 for the On, Off, SET -, RES + and Cancel switches.

⇒ | If any of the resistance measurements for the On, Off, SET -, RES + and Cancel switches are not within the listed resistance values, replace the steering wheel controls switch - left.

Function Switch | Minimum Resistance Value | Maximum Resistance Value
--- | --- | ---
OFF | O.L. | O.L.
ON | 6.5k Ohms | 7.0k Ohms
- SET | 2.2k Ohms | 2.4k Ohms
+ RES | 3.7k Ohms | 3.9k Ohms
Cancel | 1.4k Ohms | 1.6k Ohms

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Steering Wheel Control Switch Assembly Replacement

• | Control Module References for BCM replacement, setup, and programming