DME Control Unit Chip Installation

Tools

• Phillips screwdriver
• Straight-tip screwdriver
• 7 mm wrench or 7 mm socket and ratchet

Other Procedures Needed

• DME-01: DME Control Unit Removal and Installation

Procedure

1. Using DME-01, remove the DME Control Unit (and KLR for turbos).

2. Before removing the control unit(s) from the mounting bracket, note carefully how they are mounted — drawing a sketch is recommended, especially for turbocharged cars where there are two units. Then remove the control unit(s) from the mounting bracket.

3. Place the control unit(s) on a clean, dry, flat surface.

4. If the air in your work area is particularly dry or static electricity is a concern, use a grounding strap on your wrist. Static electricity can permanently damage the chip.

5. Turn the control unit so that the back side of the module is facing up.

6. Using a small flat-tip screwdriver, pry up the casing tabs on the rear of the module.

7. When all tabs are raised, slide the module cover off.

8. Inside the unit are two printed circuit boards mounted face-to-face. Separation between the boards is maintained by plastic posts mounted to the bottom circuit board; the top board clips onto the top of the posts via tabs. The two boards are connected electrically via a ribbon cable at the end opposite the electrical connector.

9. To separate the boards: place the tip of a small flat-tip screwdriver between the split at the middle of each post and pry gently back and forth until the two halves separate. (Some posts have a pin in the center that must be pulled out before the halves can separate.)

10. Once all posts are separated, lift the top circuit board up on the side closest to the ribbon cable, then slide the board toward the ribbon cable side to extract it from the electrical connector.

11. "Open" the circuit boards by laying them out flat.

12. The chip to be replaced should be identifiable as the only chip on the boards not soldered in place — instead, it will be inserted into a socket connector (applies to late model cars, 1985.5 and newer).

Note (turbocharged cars): Before removing the old chip, confirm you have identified the correct chip. On 1988 and newer cars, the DME control unit uses a 28-pin chip while the KLR uses a 24-pin chip. Pre-1988 turbo cars use a 24-pin chip in both units. Mark the old chips before removal to identify which control unit each came from, in case you need to revert to the factory chips. Also note the chip orientation in the socket before removing — both the socket and the chip have an indent on one end. Installing the new chip with the indents misaligned may permanently damage it.

13. To remove the old chip: slide a small flat-tip screwdriver under one end of the chip and pry up gently. Move to the other end and pry up gently. Alternate between both ends until the chip comes completely free. Do not attempt to remove the chip entirely from one end in a single motion.
14. Install the new chip: align all legs with their respective holes in the socket and confirm the orientation of the chip is correct (indents lined up). Slide the chip into the socket and gently press down on the center until it is fully seated.
15. Fold the two circuit boards together and slide the top circuit board into the slot on the electrical connector.
16. Ensure the posts on both circuit boards are aligned and press down gently to snap them together.
17. Install the control unit cover and bend the tabs to hold the cover in place.
18. Mount the control unit(s) to the mounting bracket.
19. Before bolting the control unit(s) into the car, attach the electrical connector (and the boost sensing hose for the KLR on turbocharged cars).
20. Using DME-01, install the control unit(s) into the car.