Automatic Level Control Compressor Motor Always On

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2004 GMC Yukon XL, 2004 GMC Yukon, 2004 Chevrolet Tahoe, 2004 Chevrolet Suburban, and 2004 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

Step	Action	Yes	No
Schematic Reference: Automatic Level Control Suspension Schematics
1	Did you perform the Automatic Level Control Diagnostic System Check?	Go to Step 2	Go to Diagnostic System Check - Automatic Level Control
2	Is the rear of the vehicle too high?	Go to Step 3	Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
3	Disconnect the air tube from the compressor. Does the rear of the vehicle drop?	Go to Step 4	Go to Step 6
4	Disconnect the compressor motor relay. Does the compressor motor continue to run?	Go to Step 5	Go to Step 7
5	Test the battery positive voltage circuit of the compressor motor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 8	-
6	Inspect all air tubes for kinked, bent and blockage. Check the exhaust valve for blockage. Did you find and correct the condition?	Go to Step 8	-
7	Replace the compressor motor relay. Did you complete the replacement?	Go to Step 8	-
8	Operate the system in order to verify the repair. Did you correct the condition?	System OK	Go to Step 3