Control Module - Interchangeability
418-03DATE
4/97
XK8
MODEL
1997 MY-ON
XK8 Range
VIN
001246-ON
Control Modules - Compatibility - Interchanging Between Vehicles
Issue:
To cover the many variations in vehicle specification which are available in various markets, information is programmed into the Control Modules (CM) during vehicle manufacture which in many cases may be specific to a very limited number of vehicles within a single market. For example, the Body Processor Module (BPM) of a coupe vehicle does not contain the control system for the power operated soft top of a convertible model.
Should a similar, but not identical, CM from one vehicle be installed in a second vehicle, this may result in various malfunctions in the second vehicle. Since the CM may then "learn" information from the second vehicle, incorrect data would then be transferred back to the first vehicle when the CM is transferred back to its original location. This is particularly applicable in the case of the Engine Control Module (ECM).
Action:
When diagnosing electrical malfunctions, assume that no defect exists in the relatively robust CM set in the vehicle (Illustration 1). Since a defect is more likely in connectors or switches, initial diagnosis should concentrate on these components.
If further diagnosis appears to point to a defect within a control module, note the 3 conditions shown next before interchanging control modules between identical vehicles to confirm diagnosis.
1. Refer to illustration 2, which shows a typical VCATS label, located on the floor of the luggage compartment of XK8 models. Each label is specific to each individual vehicle, and lists the VIN of the vehicle along with the part numbers of the CMs originally fitted to the vehicle during manufacture.
2. In the example above, the part number of the Body Processor Module is identified as: LJA 2500AG/055. The basic part number LJA 2500AG has been programmed during vehicle manufacture for the specific market and features of the vehicle concerned, and is identified as /055.
This would be the complete part number for a replacement BPM for the vehicle concerned, if it were necessary to order one from Jaguar Parts Operations.
Note that the suffix /055 (in the example above) does not appear on the label on the CM concerned. This number appears only on the VCATS label of the vehicle.
3. It is permissible to temporarily interchange a CM from another vehicle for testing purposes, only if:
^ The full vehicle history of both vehicles is available.
^ The history of both vehicles indicates that the CM in question has not previously been replaced by a CM from another vehicle or by a replacement part.
^ The VCATS label information for the full part number of the CM in question on both donor and recipient vehicle is identical, as illustrated above.
^ The donor vehicle is known to have no electrical defect.
Always disconnect the battery first, and reconnect it after connecting the replacement CM. The possibility exists, particularly for control modules that control the movement of door windows or power operated convertible tops, for inadvertent uncontrolled operation of these systems, if the battery remains connected during such operations. This can result in injury to persons working on the vehicle
PARTS INFORMATION:
When ordering a replacement Control Module via Jaguar Parts Operations, list the PULL part number, as listed on the VCATS label of the vehicle in question, so that the replacement unit can be programmed before shipment to match the specification of the module being replaced.