Suspension - EAS Control Unit Diagnosis

No: 60/01/04/NAS
Ref:
*Issue: 2
Date: 7 September 2005*

EAS Control Unit Diagnostic Paths

AFFECTED VEHICLE RANGE:
*Range Rover (LM) 2003 2005 Model Year*

Updated information is noted by asterisks.

SITUATION:

AIR SUSPENSION PROBLEM INVESTIGATION

Troubleshooting Range Rover (LM) Electronic Air Suspension Electronic Control Units requires both care and following set procedures to avoid unnecessary ECU replacement. The ECU stores fault codes for some, but not all, air suspension system component failures. In some circumstances, changing the ECU will re-activate the system but not solve the route cause of the failure.

RESOLUTION:
VERIFY ROOT CAUSE OF EAS PROBLEM
The flow diagrams in this bulletin define the only three reasons for changing the Air Suspension ECU.

The diagrams provide guidance on the diagnosis of the system that may lead to ECU replacement.

Other problems that appear to be ECU-related, are most likely caused by one of these general areas:

Other component failures
Wiring harness failures
Air harness failures

Whenever height sensor problems are resolved a re-calibration should occur to re-establish the vehicle trim heights.





PARTS INFORMATION:

DDW WARRANTY CLAIMS:





DDW requires the use of causal part numbers. Labor only claims must show the causal part number with a quantity of zero.

Normal warranty policy and procedures apply.
Material allowance is included in labor operation.

REPAIR PROCEDURE

INVESTIGATE ROOT CAUSE OF EAS PROBLEM

1. Connect T4 to the vehicle using Range Rover 14 or later and determine the stored fault codes





2. If Fault Code 53 is stored, replace the EAS ECU.





3. If Fault code 54 is stored, reflash the ECU coding file without changing the ECU.





4. If Fault Code 52 is stored, follow the flow diagram shown to determine a course of action.





5. If T4 cannot communicate with the ECU follow the troubleshooting procedures shown.





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