Scan Tool Does Not Communicate With VCM
- Perform DIAGNOSTIC SYSTEM CHECK .
- Turn ignition RUN. If MIL lights, go to next step. If MIL does not light, perform powertrain OBD system test. See POWERTRAIN ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in appropriate TESTS W/CODES article.
- Select "powertrain diagnostics" on scan tool main menu. If scan tool indicates "no data communication with vehicle" go to next step. If scan tool does not indicate "no data communication with vehicle" perform DIAGNOSTIC SYSTEM CHECK .
- Select "chassis diagnostics" on scan tool main menu. If scan tool can communicate with EBCM, go to next step. If scan tool can not communicate with EBCM, perform DIAGNOSTIC SYSTEM CHECK .
- Turn ignition OFF. Disconnect connector C4 from VCM. Check for continuity with DVOM between VCM connector terminal No. 11 and S150. If there is no continuity, go to next step. If there is continuity, go to step 7.
- Repair open or resistance in Purple 1807 circuit wiring between VCM connector terminal No. 11 and S150. Perform DIAGNOSTIC SYSTEM CHECK .
- Replace VCM. See COMPUTER CONTROLS in appropriate REMOVAL, OVERHAUL & INSTALLATION article. Perform DIAGNOSTIC SYSTEM CHECK .