Diagnostic Starting Point - Secondary and Configurable Customer Controls
Begin the system diagnosis with the Diagnostic System Check - Vehicle . The Diagnostic System Check - Vehicle will provide the following information
- The identification of the control modules which command the system
- The ability of the control modules to communicate through the serial data circuit
- The identification of any stored DTCs and their status
The use of the Diagnostic System Check - Vehicle will identify the correct procedure for diagnosing the system and where the procedure is located.
Symptoms - Secondary and Configurable Customer Controls
| IMPORTANT | Perform the Diagnostic System Check - Vehicle before using the Symptom Tables in order to verify that all of the following conditions are true: There are no DTCs set. The control modules can communicate via the serial data link. Review the system operation in order to familiarize yourself with the system functions. Refer to Steering Wheel Controls Description and Operation . |
Visual/Physical Inspection
- Inspect for aftermarket devices which may affect the operation of the Steering Wheel Controls System. Refer to «Checking Aftermarket Accessories»(ref-267924-S19208784672007101700000) .
- Inspect for easily accessible or visible system components for obvious damage or conditions which may cause the symptom.
Symptom List
Refer to Steering Wheel Controls Inoperative in order to diagnose the symptom.
Diagnostic Instructions
- Perform the «Diagnostic System Check - Vehicle»(ref-267923-S26873286382007101700000) prior to using this diagnostic procedure.
- Review «Strategy Based Diagnosis»(ref-267923-S16575275542007101700000) for an overview of the diagnostic approach.
- «Diagnostic Procedure Instructions»(ref-267923-S13300682012007101700000) provides an overview of each diagnostic category.
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.
- If a single switch function is inoperative, test the suspect switch. Refer to component testing.
Circuit/System Testing
| CAUTION | Refer to SIR Caution . |
| IMPORTANT | It is recommended that Component Testing is performed before Circuit Testing when diagnosing steering wheel controls. |
- Ignition OFF, disconnect the harness connector at the audio steering wheel control switch.
- Ignition ON, Radio ON, test for 8.5-12 volts between the 10-volt reference circuit and ground at the harness connector. If less than 8.5 volts, test 10-volt reference circuit for short to ground or open/high resistance. If the circuit test is normal, replace the radio.
- Test for 0-0.5 volts between the signal circuit and ground at the harness connector. If greater than 0.5 volt, test the signal circuit for a short to voltage. If the circuit test is normal, replace the radio.
- Test for 8.5-12 volts between the supply voltage circuit and the signal circuit 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.
- Ignition OFF, disconnect the harness connector at the radio.
- Test for infinite resistance between the signal circuit and ground at the harness connector. If less than infinite ohms of resistance, test the signal circuit for a short to ground. If the circuit test is normal, refer to component testing.
- If all circuit test normal, refer to component testing.
Component Testing
| CAUTION | Refer to SIR Caution . |
- Ignition OFF, disconnect the harness connector at the audio steering wheel control switch.
- Test for infinite resistance between the 10-volt reference terminal and the signal terminal with the switch in the open position. If less than infinite resistance, replace the switch.
- Test resistance values between the 10-volt reference terminal and the signal terminal with the switch closed in each position and verify readings are approximate to what the schematic reads. If values do not, replace the switch.