Range Rover Sport (LS) V8-4.2L SC (2006)
Information Bus: Technical Service Bulletins
Electrical - CAN Faults Re: ABS Module Diagnosis
No: LS100-003
Issue: 1
Date: 01 Dec 2006
SECTION: 100-00 - GENERAL INFORMATION
CAN Faults Relating to the ABS Module Diagnosis
AFFECTED VEHICLE RANGE:
Range Rover Sport (LS) VIN: 6A900129 onwards
CONDITION SUMMARY:
DIAGNOSTIC GUIDANCE FOR CAN FAULTS RELATING TO ABS MODULE DIAGNOSIS
Situation: This bulletin has been issued to provide diagnostic guidance for Control Area Network (CAN) faults relating to the Anti-lock Braking System
(ABS) module.
Action: Should a CAN fault arise, refer to the Repair Procedure detailed in this bulletin to resolve the concern.
PARTS:
No parts required for this bulletin. Diagnostic information only.
WARRANTY:
No warranty provided for this bulletin. Diagnostic information only.
Normal warranty policy and procedures apply.
REPAIR PROCEDURE
CONTROL AREA NETWORK (CAN) FAULTS AND PRINCIPLES OF OPERATION
--CAN FAULT CATEGORIES--
NOTE: CAN faults may be categorized as either 'CAN Data indicating a fault' or 'Missing CAN Data' and will indicate the potential problem as follows:
-
'CAN Data Indicating a Fault' is where a CAN signal is being received by a control module and contains data that is either indicating a fault
condition or is invalid because it is out of the specified range for the signal. This type of data will occur because of a specific fault with the system
from where the signal has been sent.
-
'Missing CAN Data' is where CAN signals are not being transmitted. Signals may be identified as missing from a particular system or a general
CAN bus failure may be identified. The DTC description will identify the system from which specific signals may be missing. A general CAN bus
failure can be caused by a problem in a control module, but is typically an indication of a problem with the CAN bus wiring.
--PLAUSIBILITY FAULTS RELATED TO THE CAN--
NOTE: A plausibility fault is not a CAN fault, though a CAN issue could have contributed to the fault being raised. To trace a plausibility fault it will
be necessary to check all sensors relating to the plausibility and the CAN communication between the relevant control modules.
Principles: Land Rover vehicles use a variety of sensors located around the vehicle. The systems relying on these sensors use plausibility checks to
monitor their 'health'. For example, the health of a brake pedal switch may be monitored by checking if the brakes master cylinder pressure increases
when the brake pedal switch operates. Often plausibility checks will be carried out by comparing a sensor signal to another signal that is being sent via
the CAN bus. A plausibility fault is therefore not a CAN fault but in order to trace a plausibility fault it may be necessary to be aware that CAN issues
could have contributed to the fault being raised. If a system shows a plausibility fault it is necessary to check all sensors relating to the plausibility and
the CAN communication between the relevant control modules.
--TRACING A CAN FAULT CHAIN TO ROOT CAUSE--
NOTE: The root cause of a CAN fault can only be determined after the fault chain is traced back to the first control module. The first control module
should contain DTCs indicating a hard fault or that the module may have shut down completely. A module has shut down completely if diagnostic
communication with that module can not be established.
Principles: Complex vehicle systems such as Anti-lock Braking System (ABS) or Dynamic Stability Control (DSC) use input signals from sensors that