Diagnosis And Testing - Remote Radio Switches

WARNING:

On vehicles equipped with airbags, refer to electrical, restraints before attempting any steering wheel, steering column, or instrument panel component diagnosis or service. Failure to take the proper precautions could result in accidental airbag deployment and possible personal injury.

Any diagnosis of the Audio system should begin with duplicating the customer concern (verify the problem), include checking for applicable Technical Service Bulletins (TSB) and the use of a diagnostic scan tool. Check for any Diagnostic Trouble Code (DTC) data. If a DTC is found, refer to DTC INDEX and perform the appropriate diagnostic procedure before proceeding in this article. Refer to the appropriate wiring information.

Remove the remote radio switch(es) from the steering wheel. Refer to SWITCH, REMOTE RADIO, REMOVAL AND INSTALLATION .

Use an ohmmeter to check the switch resistances as shown in the Remote Radio Switch Test chart.

REMOTE RADIO SWITCH TEST
Switch	Switch Position	Minimum Resistance (kilohms)	Nominal Resistance (kilohms)	Maximum Resistance (kilohms)
Right	Volume Up	5.22	5.32	5.42
Right	Volume Down	9.18	9.28	9.38
Right	Mode Advance	0	0	0
Left	Seek Up	1.05	1.15	1.25
Left	Seek Down	2.82	2.92	3.02
Left	Pre-Set Station Advance	0.46	0.47	0.48

If the switch resistance checks OK, go to Step 4 . If not OK, replace the ineffective switch.
Check for continuity between the ground circuit cavity of the steering wheel wire harness connectors for the switches and a good ground. There should be continuity. If OK, go to Step 5 . If not OK, repair the open ground circuit as required.
Disconnect the appropriate wire harness connector from the Body Control Module (BCM). Check for continuity between the radio control circuit cavity of the steering wire harness connectors for the switches and a good ground. There should be no continuity. If OK, go to Step 6 . If not OK, repair the shorted radio control circuit as required.
Check for continuity between the radio control circuit cavities of the steering wheel wire harness connectors for the switches and the BCM wire harness connector. There should be continuity. If OK, use a diagnostic scan tool and the appropriate diagnostic procedures to test the BCM, the Radio Receiver Module (RRM) and the Controller Area Network (CAN) data bus. If not OK, repair the open radio control circuit as required.