Steering Wheel Controls Inoperative Mute/Seek
Diagnostic Fault Information
Important: Always perform the
Diagnostic System Check - Vehicle
prior to using this diagnostic procedure.
Circuit/System Description
The body control module (BCM) supplies voltage to the MUTE/SEEK + multiple momentary contact switch and monitors the steering wheel control 2 signal circuit. 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 BCM identifies the selection, then sends a serial data message that is received by the component controlled, activating the feature.
Diagnostic Aids
| • | This diagnostic is for the audio steering wheel controls for vehicles not equipped with RPO K59 adaptive cruise. |
| • | Before diagnosis of the steering wheel controls, ensure the primary controls of the associated component are functioning properly. |
| • | Review with the schematic when testing switch resistance values. |
| • | If a single switch function is inoperative, test the suspect switch. Refer to component testing. |
Reference Information
Schematic Reference
Steering Wheel Schematics
Connector End View Reference
Description and Operation
Steering Wheel Controls Description and Operation
Electrical Information Reference
Scan Tool Data List
Scan Tool Data List
Circuit/System Verification
Ignition ON, observe the scan tool ACC Gap Switch parameter while pressing and releasing the Mute/Seek + switches. The reading should be 2.4 volts with UP pressing Seek +, and 1.1 volts with DN pressing Mute, and inactive when released.
Circuit/System Testing
Important: It is recommended that Component Testing be performed before Circuit Testing when diagnosing steering wheel controls.
Caution: Refer to SIR Caution in the Preface section.
- Ignition OFF, disconnect the C1 harness connector at the MUTE/SEEK + switch .
- Ignition ON, test for ignition voltage between the ignition circuit terminal 5 and ground.
| ⇒ | If less than the specified range, test the ignition circuit for a short to ground or open/ high resistance. If circuit test normal, and the fuse is ok, replace Run/Crank relay. |
- Test for 0 volts between the signal circuit terminal 6 and ground.
| ⇒ | If greater than the specified range, test the signal circuit for short to voltage. If circuit test normal, replace BCM. |
- Test for ignition voltage between the ignition circuit and the signal circuit terminal 6.
| ⇒ | If less than the specified range, test the signal circuit for an open/high resistance. If circuit test normal, replace BCM. |
- Ignition OFF, disconnect the C2 harness connector at the BCM.
- Test for infinite resistance between the signal circuit terminal 57 and ground.
| ⇒ | If less than the specified range, test the signal circuit for short to ground. If circuit test normal, test or replace switch. |
- If all circuits test normal, test or replace the switch.
Component Testing
Caution: Refer to SIR Caution in the Preface section.
- Ignition OFF, disconnect the C1 harness connector at the MUTE/SEEK UP switch.
- Test for infinite resistance between the signal terminal 6 and the ignition voltage terminal 5 with the switch in the open position.
| ⇒ | If not the specified value, replace the switch. |
- Test for less than 5500 ohms between the signal terminal and the voltage terminal with the switch closed in each position.
| ⇒ | If not the specified value, replace the switch. |
Repair Instructions
Important: Always perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
Steering Wheel Controls Inoperative Preset/Vol
Diagnostic Fault Information
Important: Always perform the
Diagnostic System Check - Vehicle
prior to using this diagnostic procedure.
Circuit/System Description
The CD Changer 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 CD Changer then identifies the switch selected to activate the feature, otherwise sends a serial data message that is received by the controlled component activating the feature.
Diagnostic Aids
| • | Before diagnosis of the steering wheel controls, ensure the primary controls of the associated component are functioning properly. |
| • | If a single switch function is inoperative, test the suspect switch. Refer to component testing. |
| • | A poor connection at the right switch could cause both banks of switches to be inoperative or malfunction. |
Reference Information
Schematic Reference
Steering Wheel Schematics
Connector End View Reference
Description and Operation
Steering Wheel Controls Description and Operation
Electrical Information Reference
Scan Tool Data List
Scan Tool Data List
Circuit/System Verification
Ignition ON, observe the scan tool Band status parameter while pressing and releasing the source switch. The reading should change bands.
Circuit/System Testing
Important: It is recommended that Component Testing be performed before Circuit Testing when diagnosing steering wheel controls.
Caution: Refer to SIR Caution in the Preface section.
- Ignition OFF, disconnect the C2 harness connector at the steering wheel control switch.
- Ignition ON, test for 9.5-10.5 volts between the ignition circuit terminal 3 and ground.
| ⇒ | If less than the specified range, test the ignition circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace the CD changer. |
| ⇒ | If greater than the specified range, test the
ignition circuit for a short to voltage. If the circuit tests normal, replace the CD changer |
- Test for 9.5-10.5 volts between the ignition circuit terminal and the signal circuit terminal 5.
| ⇒ | If less than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the CD changer. |
| ⇒ | If greater than the specified range, test the signal circuit for a short
to voltage. If circuit test normal , replace the CD changer. |
- Install a 3A fused jumper wire between the ignition terminal 3 and the signal circuit terminal 4.
- Disconnect the C1 harness connector at the steering wheel controls.
- Test for 9.5-10.5 volts between the signal circuit terminal 1 and ground.
| ⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the switch. |
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, test or replace the switch. |
- Test for 9.5-10.5 volts between the signal circuit terminal 1 and the signal circuit terminal 2.
| ⇒ | If less than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the CD Changer. |
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the CD Changer. |
- Ignition OFF, disconnect the C1 harness connector at the CD Changer.
- Test for infinite resistance between the signal circuit terminal 11 and ground.
| ⇒ | If less than the specified range, test the signal circuit for a short to ground. |
- If all circuits test normal, test or replace the steering wheel control switch.
Component Testing
Caution: Refer to SIR Caution in the Preface section.
- Ignition OFF, disconnect the C2 harness connector at the steering wheel control switch.
- Test for less than 2400 ohms between the ignition circuit terminal 3 and signal circuit terminal 4.
| ⇒ | If not the specified value, replace the steering wheel control switch. |
- Test for infinite resistance between the ignition circuit terminal 3 and the signal circuit terminal 5 with the switch in the open position.
| ⇒ | If not the specified value, replace the steering wheel control switch. |
- Test for less than 2400 ohms between the ignition circuit terminal 3 and the signal circuit terminal 5 with the switch in the closed position.
| ⇒ | If not the specified value, replace the steering wheel control switch. |
- Disconnect the C1 harness connector at the steering wheel control switch.
- Test for infinite resistance between the signal circuit terminal 1 and the signal circuit terminal 2.
| ⇒ | If not the specified value, replace the steering wheel control switch. |
- Test for less than 2000 ohms between the signal circuit terminal 1 and the signal circuit terminal 2.
| ⇒ | If not the specified value, replace the steering wheel control switch. |
Repair Instructions
Important: Always perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
