Scan Tool Does Not Communicate With VCM
WARNING: This page is about a different variant/trim than selected.
- Turn ignition RUN. If MIL lights, go to next step. If MIL does not light, perform powertrain OBD system test. See appropriate OBD SYSTEM TEST in SELF DIAGNOSTICS INTRODUCTION 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", see SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE .
- 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 anti-lock brakes diagnostic system check. See DIAGNOSTIC SYSTEM CHECK in appropriate ANTI-LOCK article in BRAKES.
- 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 6.
- Repair open or resistance in Purple 1807 circuit wiring between VCM connector terminal No. 11 and S150. Perform powertrain OBD system test. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in SELF DIAGNOSTICS - GASOLINE or ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in SELF DIAGNOSTICS - DIESEL article in TESTING & DIAGNOSIS in ENGINE PERFORMANCE.
- Replace VCM. See POWERTRAIN CONTROL MODULE in REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. Perform powertrain OBD system test. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in SELF DIAGNOSTICS - GASOLINE or ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in SELF DIAGNOSTICS - DIESEL article in TESTING & DIAGNOSTICS in ENGINE PERFORMANCE.