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 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 | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Cruise Control Switch Supply Voltage | 1 | B3794 08 | 1 | B3794 61
Cruise Control Switch Signal | B3794 08 | B3794 08 | B0835 00 | B3794 61
1. Cruise Control Inoperative/Malfunctioning

### 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 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.

### Reference Information

#### Schematic Reference

Cruise Control Schematics

#### Connector End View Reference

Cruise Control 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

• | Scan Tool Data List

• | Scan Tool Data Definitions

### 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. Refer to Inflatable Restraint Steering Wheel Module Replacement .
2. Disconnect the harness connector of the steering wheel controls switch - left.
3. Ignition ON, test for 10 volts or greater between the steering wheel control supply voltage circuit terminal 1 and ground.

⇒ | If less than 10 volts, check for an open/high resistance or for a short to ground on the steering wheel control supply voltage circuit. If the circuit tests normal, replace the BCM.

4. Ignition ON, verify that a test lamp illuminates between B+ and the cruise control switch signal circuit terminal 3.

⇒ | If the test lamp does not illuminate, test the cruise control switch signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM.

5. Ignition OFF, disconnect the harness connector C1 at the BCM.
6. Measure for 0 volts between the cruise control switch signal circuit terminal 3 and ground.

⇒ | If greater than the specified value, test the cruise control switch signal circuit for a short to voltage.

7. If all circuits test normal, test the component. If the circuits and the component tests are normal, replace the BCM.

### Component Testing

Important: 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. Refer to Inflatable Restraint Steering Wheel Module Replacement .
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.

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 | 3.8k 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