All Doors Fail To Lock & Unlock From One Switch
NOTE:
For connector terminal identification and wiring diagrams, see
BODY CONTROL COMPUTER - INTRODUCTION article. Perform VERIFICATION TEST VER-1A
after each repair.
CAUTION:
Always turn ignition switch to OFF position prior to disconnecting or connecting any module connector.
- If complaint is not with an interior front door lock switch, go to step 6 . If complaint is with an interior front door lock switch, go to next step.
- Disconnect inoperative front door lock switch connector. Using scan tool in voltmeter mode, measure voltage on switch connector middle terminal (White/Dark Green wire-left door, White/Light Green wire-right door). If voltage is more than 6 volts, repair White/Dark Green wire (left door) or White/Light Green wire (right door) for short to battery voltage. If voltage is 6 volts or less, go to next step.
- If voltage measured is 4.5-6.0 volts, go to step 5 . If voltage measured is less than 4.5 volts, determine if vehicle is equipped with Vehicle Theft Security System (VTSS). If vehicle is not equipped with VTSS, go to step 11 . If vehicle is equipped with VTSS, go to next step.
- Determine if door locks operate correctly from door key cylinder switch. If locks do not operate, go to step 11 . If door locks operate correctly from door key cylinder switch, repair open door lock switch MUX circuit (White/Dark Green wire-left door, White/Light Green wire-right door).
- Turn ignition off. Turn off all lights and accessories. Using scan tool in ohmmeter mode, measure resistance at front door lock switch connector terminal No. 3 (Black/Light Green wire). If resistance is less than 5 ohms, replace door lock switch. If resistance is 5 ohms or more, repair open Black/Light Green.
- Disconnect inoperative door key cylinder switch connector. Using scan tool in voltmeter mode, measure voltage at inoperative key cylinder switch connector terminal No. 1 (White/Dark Green - left door, White/Light Green - right door or White/Red - liftgate). If voltage is less than 4.5 volts, go to next step. If voltage is 4.5 volts or more, go to step 10 .
- Turn ignition off. Turn off all lights and accessories. Using scan tool in ohmmeter mode, measure resistance at suspect key cylinder switch connector terminal No. 2 (Black/Light Green wire). If resistance is 5 ohms or more, repair open Black/Light Green wire. If resistance is less than 5 ohms, go to next step.
- If problem is not with liftgate key cylinder switch, replace suspect door lock switch. If liftgate key cylinder switch is suspect, go to next step.
- Disconnect liftgate key cylinder switch connector. Using scan tool in voltmeter mode, measure voltage at liftgate key cylinder switch connector terminal No. 1 (White/Red wire). If voltage is more than 10 volts, repair White/Red wire for short to battery voltage. If voltage is 10 volts or less, replace liftgate key cylinder switch.
- Determine if door locks operate properly when using interior door lock switch. If door lock does not operate properly, repair open in White/Dark Green - left door, White/Light Green - right door or White/Red - liftgate wire between key cylinder switch connector and BCM connector "B". If door lock operates properly, go to next step.
- Access Body Control Module (BCM) connector "B". BCM is located with junction block under driver's side instrument panel. See Figure
. Remove connector cover. Do not disconnect connector. Using scan tool in voltmeter mode, backprobe connector "B". Measure voltage on terminal for suspect door or liftgate. See DOOR SWITCH MUX CIRCUITS
table. If voltage is 4.5 volts or less, replace BCM. If voltage is more than 4.5 volts, repair open MUX circuit.DOOR SWITCH MUX CIRCUITS
Door Terminal No. Wire Color Left Front 45 White/Dark Green Liftgate 44 White/Red Right Front 55 White/Light Green