Yukon/Denali XL 1500 4WD V8-6.0L VIN U (2004)
Suspension Control ( Automatic - Electronic ): Initial Inspection and Diagnostic Overview
Diagnostic Starting Point - Automatic Level Control (ALC)
Diagnostic Starting Point - Automatic Level Control
Begin the system diagnosis with the Diagnostic System Check - Automatic Level/Control 7. You may want to review the Automatic Level Control
Description and Operation 9 before beginning the diagnosis. The Diagnostic System Check will provide the following information:
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The identification of the control modules which command the system
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The ability of the control modules to communicate through the serial data circuit
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The identification of any stored diagnostic trouble codes (DTCs) and their status
The use of the Diagnostic System Check will identify the correct procedure for diagnosing the system and where the procedure is located.
Diagnostic Starting Point - Electronic Suspension Control (ESC)
Diagnostic Starting Point - Electronic Suspension Control
Begin the system diagnosis with the Diagnostic System Check.
You may want to review the Electronic Suspension Control Description and Operation before beginning the diagnosis. The Diagnostic System Check
will provide the following information:
^
The identification of the control modules which command the system
^
The ability of the control modules to communicate through the serial data circuit
^
The identification of any stored diagnostic trouble codes (DTCs) and their status
The use of the Diagnostic System Check will identify the correct procedure for diagnosing the system and where the procedure is located.
Diagnostic System Check - Automatic Level Control (ALC)
Diagnostic System Check-Automatic Level Control
Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data
circuit. The specified procedure will determine the particular condition.
3. Check for the presence of DTCs.
4. The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the
available information before tests are performed.
5. Check for the presence of DTCs in Body Control system.
6. Check for the presence of DTCs in Automatic Level Control system.
