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.

### Diagnostic Fault Information

Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance
--- | --- | --- | --- | --- | ---
B+ | 1 | B3794 08, B3794 6 | 1 | 1 | B3794 08, B3794 61
Cruise Control Switch Signal | 1 | B3794 08, B3794 6 | 1 | B3794 08 | B3794 08, B3794 61
Cruise Control Indicator Low Reference | -- | 2 | 2 | 2 | --
1. Cruise Control Malfunction 2. Cruise Control Indicator Disabled

### Circuit/System Description

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.

### Reference Information

#### Schematic Reference

• | Cruise Control Schematics

• | Exterior Lights 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 B+ circuit terminal 1 and ground.

⇒ | 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.

3. Test for B+ between the B+ 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

1. Disconnect the harness connector at the steering wheel controls switch-left.
2. Cruise control switch ON, measure the resistance between terminal 1 and terminal 3 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 | 6.5k Ohms | 7.1k 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