Control Modules - Compatibility Between Vehicles (SECTION 418, NO. 03)

CONTROL MODULES - COMPATIBILITY BETWEEN VEHICLES

TECHNICAL SERVICE BULLETIN

CONTROL MODULES - COMPATIBILITY, INTERCHANGING BETWEEN VEHICLES

Model(s): 1997-98 Jaguar XK8

1998 Jaguar XJ8, XJR

Section 418: Electrical Distribution & Electronic Control System

Bulletin Number: 418-03

Date: April, 1998

VEHICLES AFFECTED

• 1997 MY-On XK8 range, VIN 001001-On.
• 1998 MY-On V8 XJ series, VIN 812256-On.

ISSUE

To cover the many variations in vehicle specification which are available in various markets, information is programed 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 on 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. See Fig 1 and Fig 2 . 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 below before interchanging control module between identical vehicles to confirm diagnosis.

1. See Fig 3 , which shows a typical VCATS (Vehicle Configuration And Test System) label, located behind the spare tire on the trunk floor of XK8 models and behind the trunk trim on the left side of the spare tire on V8, XJ Series. Each label is specific to each individual vehicle, and lists the VIN of the vehicle a long with the part numbers of the CMs originally installed in the vehicle during manufacture.
2. In the example above, the part number of the Body Processor Module is identified as: LJA 2500AG/055. In the above, 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, illustrated above.
   • The donor vehicle is known to have no electrical defect.

PARTS INFORMATION

When ordering a replacement Control Module via Jaguar Parts Operations, list the FULL 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.