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Date sent: Mon, 16 Jun 1997 14:46:22 -0500
Subject: J.C. installation

I found that the available instructions, including those from Duane Collie, did not encompass all the types of DME units. The problem is that earlier E36 DME's were constructed in a different way, apparently the same as E30's. That is the components face inward on the circuit board causing difficulty in getting to the Chip to exchange it. I know that others have encountered the same problem.

I have a 1992 E36 325i. Apparently, BMW/Bosch started manufacturing E36 DME's using the same manufacturing process as the E30. That is with the components facing inward on the two circuit boards. The boards are a bitch to get apart. The people on the Digest make it sound easy to change E36 Chips because theirs is the later style with the components, including the Chip facing outward and easily accessible to change.

After numerous attempts, I finally got instructions from a fellow digester, Kim Lau. He got the instructions from Jim C. himself. The instructions for getting the DME out of the compartment on the firewall are the same. I think the E30s may require access from behind the glovebox.
Bob Roberts

Author: Bob Roberts
I noticed in the digest that you have a 1992 325i with the J.C. Chip. Did you install it yourself? I have a J.C. Chip to install in my 1992 325i, but have been unable to gain access to the chip plug in. Apparently, I have to open up the circuit boards but have been unable to do so. Do you know how?
Bob Roberts

Author: Kim Lau
I did install it myself, but I never did get both circuit boards completely apart. After a frustrating night of trying to get the boards apart. I sent Jim an email request, asking for directions on how to do it, to his credit, he responded that very same day :). So armed with his directions, (see below) I tried to separate the boards again that night. I got about as far as I did the night before, no matter what I tried I couldn't get the board apart. I did get the boards apart enough to CAREFULLY stick a screwdriver underneath the eprom to pry it loose. I then took the new eprom with a pair of tweezers and placed it on top of the socket, I CHECKED TWICE to make sure the pins were seated properly on the socket then I GENTLY pressed on the eprom to seat it. I checked the eprom again, to make sure that none of the pins were bent under the eprom. I reassembled the DME, put it back in the car, and started the car to make sure it worked. I know that, that's not the way its suppose to go in, but it worked for me. I hope this helps, let me know if you have any other questions. Good luck,

Jim C's reply to my request for help

First the FRONT of the boards is where the connex. is... The REAR is the opposite side .. where the ribbon cable hooks the boards together ..

1. Pop the plastic risers apart at the REAR of the board ..

2.The connector is 3 rows .. the bottom 2 stay with the bottom board, and the top row comes out with the TOP board ..

3. To separate .. make both tabs come inward with small screwdrivers (the small plastic ones inside the connector at the ends of the top row of pins). And now swivel the BACK end of the board UP and wiggle the front out .. What holds it is a small "line" of plastic that mates with a valley.. by lifting the REAR of the boards as far as they will go, and wiggling it a bit .. you can get it apart

Otherwise find an independent garage and have them install it for you ..

End of J.C.'s Instructions

I found the instructions from Jim C. to work.
Kim Lau

I might add that when lifting the circuit board up, I used a very narrow flat tipped screwdriver about 1/8 to 1/4 inch from one end to pry that corner of the board and start it out of the valley referenced. Be careful
not to crack the board, once started it comes out easily. I did break off a couple of plastic tabs which held the circuit board at the back of the connector, i.e, where it pulls out and lifts up. This does not affect > operation since the connector holds the circuit board securely when it is in place. I can't imagine how you got your chip in without getting the boards apart. I could barely see inside mine, plus I had to remove the protective shield covering the chip before I could switch the chips.

This was a learning experience. I think I could do one easily now after seeing how they come apart. But, I am going to be very careful about anything I read on the digest in the future. It may not be as easy (or even the same!) as people represent.

Bob Roberts

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