Steering Wheel Controls Inoperative
Steering Wheel Controls Inoperative
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
Circuit/System Description
The radio supplies voltage to the audio steering wheel control momentary contact switches and monitors the return signal. Each switch state is associated to a set resistance value and when pressed a specific voltage drops across the resistor unique to that switch. The radio identifies the switch selection and activates the feature. Otherwise the radio sends a serial data message to the component controlled by the switch and activates the feature.
Diagnostic Aids
* This diagnostic is for the audio steering wheel controls.
* Before diagnosis of the steering wheel controls, ensure the primary controls of the associated component are functioning properly.
* Review 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 Secondary/Configurable Control Schematics (Steering Wheel Secondary/Configurable Control Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Steering Wheel Controls Description and Operation (Steering Wheel Controls Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Testing
Caution: Refer to SIR Caution (SIR Caution) .
Important: It is recommended that Component Testing is performed before Circuit Testing when diagnosing steering wheel controls.
1. Ignition OFF, disconnect the harness connector at the audio steering wheel control switch.
2. Ignition ON, Radio ON, test for 8.5-10.5 volts between the 10-volt reference circuit terminal 2 and ground at the harness connector.
• If less than specified, test the circuit for short to ground or open/high resistance. If the circuit test is normal, replace the radio.
• If greater than specified, test the circuit for short to voltage. If the circuit test is normal, replace the radio.
3. Test for less than 0.5 volts between the signal circuit terminal 4 (late production) or 1 (early production) and ground.
• If greater than specified, test the circuit for a short to voltage. If the circuit test is normal, replace the radio.
4. Test for 8.5-12 volts between the supply voltage circuit terminal 2 and the signal circuit terminal 4 (late production) or 1 (early production) at the harness connector.
• If less than 8.5 volts, test the signal circuit for an open/high resistance. If the circuit test is normal, replace the radio.
5. Ignition OFF, disconnect the X1 harness connector at the radio.
6. Test for infinite resistance between the signal circuit terminal 11 and ground.
• If less than infinite resistance, test the circuit for a short to ground. If the circuit test is normal, refer to component testing.
7. If all circuit test normal, refer to component testing.
Component Testing
Caution: Refer to SIR Caution (SIR Caution) .
1. Ignition OFF, disconnect the harness connector at the audio steering wheel control switch.
2. Test for infinite resistance between the 10-volt reference terminal 2 and the signal terminal 4 (late production) or 1 (early production) with the switch in the open position.
• If less than infinite resistance, replace the switch.
3. Test resistance values between the 10-volt reference terminal 2 and the signal terminal 4 (late production) or 1 (early production) with the switch closed in each position and verify readings are approximate to what the schematic reads.
• If values do not, replace the switch.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Steering Wheel Control Switch Assembly Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for Radio replacement, setup, and programming.