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 | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
BCM B+ Terminal 3 | B3794 08, B1529 00, B3922 00 | B3794 08, B1529 00, B3922 00 | -- | --
BCM B+ Terminal 17 | B3794 08, B1529 00, B3922 00 | B3794 08, 1529 00, B3922 00 | -- | --
Cruise Control Switch Signal | B3794 08 | B3794 08 | B3794 08 | --

### 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 ECM indicating the status of the cruise control switches.

### 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, 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

1. Ignition OFF, disconnect the X3 harness connector at the BCM.
2. Verify that a test lamp illuminates between the BCM F9 fuse B+ circuit terminal 3 and ground.

⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

3. Ignition OFF, connect the X3 harness connector at the BCM.
4. Disconnect the harness connector at the turn signal/multifunction switch.
5. Ignition ON, test for B+ between the B+ circuit terminal 6 and ground.

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

6. Ignition ON, test for B+ between the B+ circuit terminal 6 and the signal circuit terminal 5.

⇒ | 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.

7. Ignition ON, verify that a test lamp does not illuminate between B+ and the signal circuit terminal 5.

⇒ | If the test lamp illuminates, test the signal circuit for a short to ground. If the circuit test normal, replace the BCM.

8. If all circuits test normal, test or replace the turn signal/multifunction switch.

### Component Testing

1. Disconnect the harness connector at the turn signal/multifunction switch.
2. Cruise control switch ON, measure the resistance between terminal 5 and terminal 6 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 turn signal/multifunction switch.

Function Switch | Minimum Resistance Value | Maximum Resistance Value
--- | --- | ---
Off | 6.7k Ohms | 6.9k Ohms
On | 1.4k Ohms | 1.6k Ohms
- SET | 2.2k Ohms | 2.4k Ohms
+ RES | 3.6k Ohms | 3.9k Ohms

### Repair Instructions

Perform the Diagnostic Repair Verification.

• | Turn Signal Switch Replacement

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