A Symptoms - ALC

Symptoms-Automatic Level Control

Important: The following step must be completed before using the symptom tables.

1. Perform the Diagnostic System Check-Automatic Level Control in order to verify that all of the following are true:
- There are no DTCs set.
- The control module(s) can communicate via the serial data link.

2. Review the system operation in order to familiarize yourself with the system functions. Refer to the following:
- Automatic Level Control General Description
- Automatic Level Control General Operation

Visual/Physical Inspection
- Inspect for aftermarket devices, which could affect the operation of the Automatic Level Control System. Refer to Checking Aftermarket Accessories in Diagrams/Diagnostic Aids.
- Inspect the easily accessible or visible system components for obvious damage or conditions, which could cause the symptom.

Intermittent
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent and Poor Connections in Diagrams/Diagnostic Aids.

Symptom List
Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:
- Air Compressor Leak Test
- Rear of Vehicle High
- Rear of Vehicle Low