Circuit/System Testing

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

1. Ignition OFF, disconnect the harness connector at the left and right steering wheel control switches.
2. Ignition ON, Radio ON, test for 9.8-10.2 volts between the 10-volt reference circuit and ground at the right switch harness connector.
   • If less than 8.5 volts, test 10-volt reference circuit for short to ground or open/ high resistance. If circuit test normal, replace radio.
   • If greater than 10.5 volts, test the 10-volt reference circuit for short to voltage. If circuit test normal, replace radio.
3. Test for 8.5-10.5 volts from the 10-volt reference circuit and toggle to the signal circuits at the left and right switch harness connectors.
   • If less than 8.5 volts, test the signal circuit for an open/ high resistance. If the circuit test normal, replace the radio.
   • If greater than 10.5 volts, test the signal circuit for short to voltage. If the circuit test normal, replace the radio.
4. Ignition OFF, reconnect the right switch.
5. Ignition ON, Radio ON, test for 8.5-10.5 volts between the supply voltage circuit to the left switch and ground at the left switch harness connector.
   • If less than 8.5 volts, test the voltage circuit to the left switch for a short to ground or open/ high resistance. If the circuit test normal, test or replace right switch.
   • If greater than 10.5 volts, repair the voltage supply circuit for a short to B+.
6. Test for 1-2 volts when pressing the mute button between the signal circuit and ground at the left switch harness connector.
   • If less than 1-volt, test the signal circuit for a short to ground. If the circuit test is normal, replace the radio.
7. If all circuits test normal, refer to Component Testing .