Issue 1 - Replacing PROM
1. Check that the 'anti-back out' plate on the face of each harness connector is still in place after disconnecting the connector.Note:
In the event of the anti-back out plate becoming loose or detached, secure it to the face of the connector, pressing it firmly in place.
Caution:
Perform the following operations at an anti-static workstation (previously supplied) while wearing a grounding wrist-strap (Illustration 1). Additional work mats can be sourced locally, such as Radio Shack cat. no. 910-3780.
2. Place the ECM on the anti-static work mat, with one flat face to the mat. Looking towards the two connectors, the red connector should be to the upper right, the black connector to the lower left.
3. Note the orientation of the top cover with its mounting lugs, relative to the ECM casing. Mark both the cover and casing, using a felt-tip marker pen, to assist when reassembling.
4. Remove the four retaining screws of the top ECM cover (i.e. the cover adjacent to the red connector) using a Torx 20 anti-tamper type bit. Remove the cover.
5. Remove the seven retaining screws of the printed circuit board (8, Illustration 2). Fold the printed circuit board away from the body of the ECM unit and support it on a block of wood (6, Illustration 2) so that no strain is placed on the ribbon connectors (7, Illustration 2). Allow a clearance space (5, Illustration 2) so that no damage can occur from contact with the mounting brackets.
6. The modification kit contains two microchips, one each of the 28-pin (1, Illustration 2) and 32-pin (2, Illustration 2) design.
7. Remove the covers (4, Illustration 2) from the microchips on the printed circuit board. Remove each cover by applying a side-to-side rocking action, gripping the cover lightly with combination pliers midway along each long side.
Caution:
Do not touch the printed circuit board with the pliers, or mark the surface of the printed circuit board.
8. Remove the PROM microchips from the printed circuit board using a suitable proprietary removal/reinstallation tool (Illustrations 3 & 4).
9. When inserting the replacement PROM microchips, identify the 'half moon' cutouts in both the microchip and the socket on the printed circuit board (Illustration 5).
Caution:
Correct orientation is mandatory. The cutouts in both items must be aligned as the microchip is inserted into the socket.
10. The removed microchips should be set on one side, to be returned to Jaguar.
11. Identify and install the replacement 28-pin and 32-pin microchips from the modification kit to the appropriate sockets.
12. Use great care to achieve condition '1' in Illustration 6. The microchip must lie parallel to the printed circuit board, with all pins fully engaged into their corresponding locations in the socket.
Caution:
Permanent damage to the microchip is likely in conditions B or C. Malfunctions will occur with partial engagement, as in condition D.
13. Reinstall the original covers over the replacement PROM microchips.
14. Carefully fold the printed circuit board back to its original location on the casing of the ECM, ensuring that the connector is correctly aligned to its location in the casing. Install and tighten the seven securing screws. Torque setting: 2.25-2.82 Nm (20-25 lb in).
15. Reinstall the ECM cover on the case, aligning the marks made at step 3 of this workshop procedure, prior to removal of the cover. Install and tighten the four securing screws. Torque setting: 2.25-2.82 Nm (20-25 lb in).
16. Apply the PECUS label from the modification kit to the cover of the ECM. The new label must not obscure any existing label on the unit (Illustration 7).
Note:
Use this label for T493 also.
17. Reinstall the ECM in the vehicle, by a reversal of the process used for its removal.
Note:
When reinstalling the ECM in its location, ensure that the upper spade is correctly relocated in the slot in the vehicle body, and that the ground leads are correctly reconnected.
18. Continue with the procedure for replacing the EGR valve.