Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

The instrument panel module (IPM) supplies voltage to the multiple momentary contact switches and monitors the return signal. Each switch is associated to a set resistance value, when pressed a specific voltage drop occurs through a series of resistors unique to that switch. The IPM identifies the selection, then sends a serial data message that is received by the component controlled, activating the feature. If equipped with adaptive cruise control the Gap+/Gap- switches are in place of the mute/source switches and are in the same resistor ladder circuit.

Schematic Reference

Steering Wheel Schematics

Connector End View Reference

Description and Operation

Steering Wheel Controls Description and Operation

Electrical Information Reference

Scan Tool Reference

Scan Tool Data List

Ignition ON, observe the scan tool steering wheel controls counts while pressing the steering wheel control switch. The reading should change with each switch pressed and display counts when inactive.

Caution: Refer to SIR Caution in the Preface section.

Important: It is recommended that Component Testing be performed before Circuit Testing when diagnosing steering wheel controls.

1. Ignition OFF, disconnect the harness connector at the left and right steering wheel control switches.
2. Ignition ON, test for B+ between the ignition circuit terminal 1 and ground at the left harness connector.

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

3. Test for less than 0.5 volt between the signal circuit terminal 4 and ground.

⇒	If greater than 0.5 volt test the signal circuit for a short to voltage. If the circuit tests normal replace the IPM.

4. Install a 3-amp fused jumper wire at the ignition circuit terminal 1 at the left harness connector. Toggle the jumper wire between the signal circuit terminals 4 at the left and right harness connectors. Verify DTC B3622 sets.

⇒	If the DTC does not set, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the IPM.

5. Reconnect the left switch.
6. Test for B+ between the ignition terminal 1 and ground at the right harness connector.

⇒	If less than the specified value, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal test or replace the left switch.

7. If all circuits test normal, test or replace the switch.

1. Ignition OFF, disconnect the harness connector at the steering wheel control switches.
2. Test the left switch for 2360-2400 ohms of resistance between the ignition circuit terminal 1 and the ignition circuit terminal 5.

⇒	If the resistance is not within the specified range, replace the faulty switch.

3. Test for infinite resistance between the ignition circuit terminal 1 and the signal circuit terminal 4 with the switch in the open position.

⇒	If less than infinite resistance, replace the switch.

4. Test resistance values between the ignition circuit terminal 1 and the signal terminal 4 with the switch closed in each position and verify readings are approximate to what the schematic reads.

⇒	If values do not match, replace the switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.