System Will Not Disarm Using Door Lock Cylinder Switch
- Connect scan tool to Data Link Connector (DLC). Select BODY CONTROL MODULE. Select INPUTS. Select KEY DISARM. Insert ignition key into door lock cylinder. Turn key to unlock position (counterclockwise). If scan tool displays ON, go to next step. If scan tool does not display ON, go to step 3).
- Check door lock cylinder switch for intermittent malfunction, by turning switch several times while monitoring scan tool. If door lock cylinder switch is good, check for intermittent operation in Brown/Purple wire between Brown, 24-pin Body Control Module (BCM) connector C1, terminal A03 and door lock cylinder switch connector terminal No. 2. Go to next step. See Fig 1
.
- Check for intermittent operation in Black wire between door lock cylinder switch connector terminal No. 1 and chassis ground connection located at body wiring harness, lower left "A" pillar. If problem was found repair intermittent circuit malfunction or replace door lock switch, and go to SYSTEM CHECK. If no problem was found, go to step 5).
- Disconnect connector C1 form BCM. See Fig 1
. Insert ignition key in door lock cylinder switch and turn key to unlock position (counterclockwise). Using DVOM set on ohms scale, measure resistance between BCM connector terminal A03 (Brown/Purple wire) and chassis ground. If resistance reading is less than 2 ohms, go to next step. If resistance reading is 2 ohms or more, go to step 6).
- Check for poor connection at BCM connectors. If connectors are good, replace BCM and go to SYSTEM CHECK.
- Remove door lock switch connector. Install scan tool. Select KEY DISARM. Connect a fused jumper wire between door lock switch connector terminals No. 1 (Black wire) and No. 2 (Brown/Purple wire). If scan tool displays ON, replace door lock switch and SYSTEM CHECK. If scan tool does not display ON, go to next step.
- Remove jumper wire end from terminal No. 1 (Black wire) and connect it to a good chassis ground. If scan tool displays ON, repair open in Black wire between door lock switch connector terminal No. 1 and chassis ground connection located in body wiring harness at lower left "A" pillar. Go to SYSTEM CHECK. If scan tool does not display ON, repair open in Brown/Purple wire between door lock switch connector terminal No. 2 and BCM connector C1, terminal A03. Go to SYSTEM CHECK.
Courtesy of GENERAL MOTORS CORP.
Courtesy of GENERAL MOTORS CORP.