Steering Wheel Controls Inoperative 2.8L, 3.6L (LP1/LY7)

The radio supplies voltage to the steering wheel control 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 radio then identifies the selection to activate the feature, otherwise sends a serial data message received by the controlled component activating the feature.

Before diagnosis of the steering wheel controls, ensure the primary controls of the associated component are functioning properly.

Schematic Reference

Steering Wheel Secondary/Configurable Control Schematics

Connector End View Reference

Description and Operation

Steering Wheel Controls Description and Operation

Electrical Information Reference

Scan Tool Reference

Ignition ON, observe the scan tool Radio Volume control parameter while pressing the volume switch. The reading should change counts.

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

Caution: Refer to SIR Caution in the Preface section.

1. Ignition OFF, disconnect the harness connector at the right steering wheel control switch.
2. Ignition ON, Radio ON, test for 8.5-10.5 volts between the ignition circuit terminal 5 and ground.

⇒	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 radio.

⇒	If greater than the specified value, test the ignition circuit for a short to voltage. If the circuit tests normal, replace the radio.

3. Test for 8.5-10.5 volts between the ignition circuit terminal 5 and the signal circuit terminal 7.

⇒	If less than the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the radio.

⇒	If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio.

4. Install a 3A fused jumper wire between the ignition circuit terminal 5 and the signal circuit terminal 6.
5. Disconnect the harness connector at left steering wheel control switch.
6. Test for 8.5-10.5 volts between the signal circuit terminal 1 and ground.

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

⇒	If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio.

7. Test for 8.5-10.5 volts between the signal circuit terminal 1 and the signal circuit terminal 2.

⇒	If less than the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal. Replace the radio.

⇒	If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio.

8. Ignition OFF, disconnect the C1 harness connector at the radio.
9. Test for infinite resistance between the signal circuit terminal 13 and ground.

⇒	If less than the specified value, test the signal circuit for a short to ground.

10. If all circuits test normal, test or replace switch.

Caution: Refer to SIR Caution in the Preface section.

1. Ignition OFF, disconnect the harness connector at the right steering wheel control switch.
2. Test for less than 1600 ohms of resistance between the signal terminal 6 and the ignition terminal 5.

⇒	If greater than the specified value, replace the steering wheel control switch.

3. Test for infinite resistance between the signal terminal 7 and the ignition terminal 5 with the switch in the open position.

⇒	If not the specified value, replace the steering wheel control switch.

4. Test for less than 1600 ohms of resistance between the signal terminal 7 and the ignition terminal 5 with the switch in the closed position.

⇒	If greater than the specified value, replace the steering wheel control switch.

5. Disconnect the harness connector at the left steering wheel control switch.
6. Test for infinite resistance between the signal terminal 1 and the signal terminal 2 with the switch in the open position.

⇒	If not the specified value, replace the steering wheel control switch.

7. Test for less than 2800 ohms of resistance between the signal terminal 1 and the signal terminal 2 with the switch in the closed position.

⇒	If greater than the specified value, replace the steering wheel control switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Steering Wheel Controls Inoperative 6.0L (LS2)

The radio supplies voltage to the steering wheel control 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 radio then identifies the selection to activate the feature, otherwise sends a serial data message received by the controlled component activating the feature.

Before diagnosis of the steering wheel controls, ensure the primary controls of the associated component are functioning properly.

Schematic Reference

Steering Wheel Secondary/Configurable Control Schematics

Connector End View Reference

Description and Operation

Steering Wheel Controls Description and Operation

Electrical Information Reference

Scan Tool Reference

Ignition ON, observe the scan tool Radio Volume control parameter while pressing and depressing the volume switch. The reading should change counts.

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

Caution: Refer to SIR Caution in the Preface section.

1. Ignition OFF, disconnect the harness connector at the right steering wheel control switch.
2. Ignition ON, Radio ON, test for 8.5-10.5 volts between the ignition circuit terminal 1 and ground.

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

⇒	If greater than the specified value, test the ignition circuit for a short to voltage. If the circuit tests normal, replace the radio.

3. Test for 8.5-10.5 volts between the ignition circuit terminal 1 and the signal circuit terminal 4.

⇒	If less than the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal. Replace the radio.

⇒	If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio.

4. Ignition OFF, disconnect the C1 harness connector at the radio.
5. Test for infinite resistance between the signal circuit terminal 13 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 switch.

Caution: Refer to SIR Caution in the Preface section.

1. Ignition OFF, disconnect the harness connector at the right steering wheel control switch.
2. Test for infinite resistance between the signal terminal 4 and the ignition terminal 1 with the switch in the open position.

⇒	If not the specified value, replace the steering wheel control switch.

3. Test for less than 2400 ohms of resistance between the signal terminal 4 and the ignition terminal 1 with the switch in the closed position.

⇒	If greater than the specified value, replace the steering wheel control switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.