Ignition MUX Switch Input Short
NOTE:
After making any repairs, perform BODY VERIFICATION TEST under VERIFICATION TESTS.
- Turn ignition off. Disconnect ignition switch 5-pin connector. See Figure. Using scan tool, select SENSORS and monitor IGNITION SW voltage. If scan tool displays 0 volts, go to next step. If scan tool does not display 0 volts, replace ignition switch. See IGNITION SWITCH & LOCK CYLINDER under REMOVAL & INSTALLATION in STEERING COLUMN SWITCHES article.
- Disconnect the ignition switch 5-way connector. See Fig 1. Locate Body Control Module (BCM) and disconnect connector C5. See COMPONENT LOCATIONS . See Figure. Measure resistance between ground and the ignition switch sense circuit in the BCM connector C5. If resistance is below 10 k/ohms, repair the ignition switch sense circuit for a short to ground. If resistance is more than 10 k/ohms, go to the next step.
- Turn the ignition off. Disconnect BCM connector C4. Disconnect BCM connector C5. See Figure and Figure . Disconnect the ignition switch 5-way harness connector. See Fig 1. Measure the resistance between the ignition switch sense circuit and the ignition switch sense return circuit. If the resistance is below 10 k/ohms, repair the ignition switch sense circuit for a short to the ignition switch sense return circuit. If the resistance is above 10 k/ohms, go to the next step.
- Turn the ignition off. Disconnect the Ignition Switch 5-way connector. See Fig 1. Disconnect the Body Control Module C4 connector. See Figure. Measure the resistance between ground and the Ignition Switch Sense Return circuit in the BCM C4 connector. If the resistance is below 10 k/ohms, repair the Ignition Switch Sense Return circuit for a short to ground. If the resistance is above 10 k/ohms, replace the Body Control Module. See BODY CONTROL MODULE under REMOVAL & INSTALLATION.