Symptoms - Automatic Level Control. GMC Truck Yukon XL Denali 2006

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2006 🢒 Yukon XL Denali 🢒 General Information 🢒 Vibration Diagnosis and Correction 🢒 Symptoms - Automatic Level Control

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

Perform the Diagnostic System Check - Vehicle in Vehicle DTC Information, before using the symptom table in order to verify that all of the following are true:

•	There are no DTCs set.

•	The control modules can communicate via the serial data link.

Review the system operation in order to familiarize yourself with the system functions. Refer to Automatic Level Control Description and Operation .

•	Inspect for aftermarket devices which could affect the operation of the Automatic Level Control System. Refer to Checking Aftermarket Accessories in Wiring Systems.

•	Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

•	Inspect the connectors to be properly seated and free of corrosion.

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

•	Automatic Level Control Compressor Motor Always On

•	Automatic Level Control Compressor Motor Inoperative