Automatic Level Control (ALC) Diagnostic System Check
- Ensure battery condition, cold cranking amperage and reserve capacity meet specifications. Replace as necessary. Install scan tool to Data Link Connector (DLC). If scan tool powers up, go to next step. If scan tool does not power up, go to SCAN TOOL DOES NOT POWER UP .
- Turn ignition on, engine off. Try to establish scan tool communication with ALC sensor. If communication with ALC sensor is established, go to next step. If communication with ALC sensor is not established, go to SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 SERIAL DATA LINK .
- Select display DTC function for ALC sensor. Record all displayed DTCs and status of displayed DTCs. If DTCs are displayed, go to BODY CONTROL MODULE (BCM) DTC DEFINITIONS table and perform correct repair procedure. If no DTCs are displayed, attempt to diagnose system by symptom. See appropriate AUTOMATIC LEVEL CONTROL article in SUSPENSION.