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
--- | --- | --- | --- | ---
Ignition Switch Signal | 2 | 2 | 1 | --
Headlamp Switch Signal | 1 | 2 | 2 | --
1. Chime always on 2. Chime inoperative

#### Circuit/System Description

The radio generates the audible warning through the left front speaker. The radio receives audible warning requests via CAN serial data from the body control module (BCM).

### Reference Information

#### Schematic Reference

• | Headlights Schematics

• | Starting and Charging Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Instrument Cluster 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

• | Scan Tool Output Controls

### Circuit/System Verification

1. Ignition ON, observe the scan tool Door Ajar parameter with all doors closed. The parameters should all display Off.

⇒ | If any parameter displays On, refer to Courtesy Lamps Always On .

2. Radio on, verify that the front left speaker is operational.

⇒ | If the left front speaker is not operational, refer to Diagnostic Starting Point - Entertainment .

3. Perform each of the following to verify proper system operation:

• | Ignition ON, headlamp ON, verify the scan tool headlamp switch parameter is active.

• | Ignition ON, headlamp OFF, verify the scan tool headlamp switch parameter is inactive.

⇒ | If not the specified value, refer to headlamp switch circuit test.

4. Perform each of the following to verify proper system operation:

• | Ignition OFF, key in ignition, verify the scan tool Key In Ignition status parameter is Key In.

• | Ignition OFF, key out of the ignition, verify the scan tool Key In Ignition status parameter is Key Out.

⇒ | If not the specified value, refer to Ignition Switch Circuit Test.

### Circuit/System Testing

#### Turn Signal/Multifunction Switch

1. Ignition OFF, disconnect the harness connector at the turn signal/multifunction switch.
2. Test for less than 1.0 ohm between the ground circuit terminal 7 and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the scan tool Headlamp Switch parameter is Inactive.

⇒ | If not the specified value, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the BCM.

4. Install a 3A fused jumper wire between the signal circuit terminal 1 and the ground circuit terminal 7. Verify the scan tool Headlamp switch parameter is Active.

⇒ | If not 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.

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

#### Ignition Switch

1. Ignition OFF, disconnect the harness connector at the ignition switch.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 2 and ground.

⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the signal circuit terminal 4 for a short to ground.

3. Ignition OFF and key out, verify the scan tool Key in Ignition parameter is key out.

⇒ | If not the specified value, test the signal circuit terminal 4 for a short to voltage. If the circuit tests normal, replace the BCM.

4. Install a 3A fused jumper wire between the signal circuit terminal 4 and the B+ circuit terminal 2. Verify the scan tool Ignition Switch is Key In.

⇒ | If not the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM.

5. If all circuits test normal, test or replace the ignition switch.

### Component Testing

#### Turn Signal/Multifunction Switch

1. Ignition OFF, disconnect the harness connector at the turn signal/multifunction switch.
2. Turn the turn signal/multifunction switch to HDLP and test for less than 1.0 ohm between terminal 7 and 1.

⇒ | If not within the specified range, replace the turn signal/multifunction switch.

3. Turn the turn signal/multifunction switch to OFF and test for infinite resistance between terminals 7 and 1.

⇒ | If not the specified value, replace the turn signal/multifunction switch.

#### Ignition Switch

1. Ignition OFF, disconnect the harness connector at the ignition switch.
2. Insert the Ignition key into the ignition switch and test for less than 1.0 ohm between terminal 2 and 4.

⇒ | If not within the specified range, replace the ignition switch.

3. Remove the ignition key from the ignition switch and test for infinite resistance between terminals 2 and 4.

⇒ | If not the specified value, replace the ignition switch.

#### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Headlamp Switch Replacement

• | Ignition and Start Switch Replacement

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