Do you know or have any information that you think would be helpful to the community and would like to share it in this blog?

You are welcome to post it if you would like to! Just go to the "Submit Post" page for more information.

Installing a Chip on the 1993-1995 BMW 325i/525i

Posted by
Did you like this article? Be the 1st to spread the word in your group!
Google Generated QR Code - Installing a Chip on the 1993-1995 BMW 325i/525i
Share This Post

This document is about installing a performance chip on a 1993 – 1995 BMW 325i or 525i ecu.

First of all, let’s locate the ecu so we can unmount it from the car. It is locate under the hood, in the engine compartment.


Taking out the BMW E36 ecu - Step 1

Refer to the drawing above; facing rearward, towards the windshield, at the upper left hand (passenger side), you will see a soft foam cover. Remove the (3) black plastic buttons that are on top and pry out the plastic tab centers to remove them and then remove the insulated foam cover.


Taking out the BMW E36 ecu - Step 2

Now, you will see a hard plastic cover. Remove this cover by removing the (4) top screws.


Taking out the BMW E36 ecu - Step 3

You will see the ECU box attached to a wire harness. Remove it by pulling it out. The ECU will just slide out.

Do not disconnect harness until the ECU is completely removed. For disconnecting the harness, just pull out the lock lever, in the direction showed by the red arrow in the picture at the Right.


Location of the ecu on the BMW E34


If your BMW is the E34 chassis model, the ECU is located under a plastic cover, as showed by the red arrow in the picture above.

Chip Installation

Please, DO NOT remove any bolt from the ecu.

There are (6) tabs holding the cover at the bottom. Using a small and sharp flat screwdriver, CAREFULLY bend the tabs away, so you can take the cover out from its original place. Please take EXTRA precautions when doing this and also when reinstalling the cover, to (1) avoid cutting your hands / fingers if the screwdriver slips and (2) avoid breaking the tabs, as they have proven to be very, very fragile.

Now, inside of the ECU, there is a white plastic cover on top of a chip. It looks like an “H” (picture below). The chip bellow it is the one to be replaced, so please unsnap the plastic cover and BEFORE removing the chip, please note the alignment of its pin #1, so the new chip can be inserted the same way (see a note about this at the end of this document).

Identifying the chip to be replaced

Take out the chip by using the same small flat screwdriver and slide it CAREFULLY under the chip for slowly pulling / prying it off its original place, little by little, from both sides. If you have a simple chip pulling tool, you may use it instead.

Removing the ecu chip

Install the performance chip, by inserting it in the socket. For doing this, point pin #1 to the same corner as the old chip, then, carefully aligning all the pins into the holes and pushing it down firmly, securing it on place. Re insert (snap) the plastic “H” shaped cover. Now you are ready to put back the ecu cover, reinstall the ecu and enjoy your NEW CAR!!!

A word of caution about installing chips

Chip pin #1 identification

For a great performance chip for these ecus (Non-EWS), please check the URL bellow. We produce and higly recommend these chips. On this chip you will get all that big companies’ chips offer, but at a much better price and it is warrantied for one full year. There is a limited supply, so hurry up and visit the site below to order before they are gone.



Website's recent related searches:

InstallingaChiponthe1993-1995BMW325i/525i   bmw e34 ecu   bmw e36 chip installation   e34 chip installing   how to connect unichip d8 to bmw computer box   how to replace chip on e34   wanted ECU for 1995 BMW 525i
Categories : Automotive Tags : , , , , , , , , , , ,

December 9, 2008

Thanks for post. Nice to see such good ideas.

March 21, 2009

Hey I bought one of those from racingchips. They are just great. It has my 325i pulling hard now. thanks!

PostedbyHenry Collins
March 21, 2009

sorry, I had a question about the chip on Will post it in the right page. Thanks

PostedbyNeftali Hernandez
March 21, 2009

Henry, I’m glad you could take advantage of our advice.

Neftali, no problem. As soon as you post your question, we will be more than glad to help.



June 2, 2009

Hi, good post. I have been wondering about this issue,so thanks for posting. I’ll definitely be coming back to your site.

April 21, 2010

Very nice post 🙂 Thank you for sharing

April 25, 2010

Good Information. Is it the same procedure for 2001 325i?

PostedbyG. Capano
April 25, 2010

No. This doesn’t apply for any 1996 and later BMW models. Those OBD-II models does not have a replaceable chip like earlier OBD-I models do.

April 25, 2010

There are places that sell for the BMW 2001 325i on eBAY. Your 1996 look somewhat similiar to my 2001. I think the third diagram look familiar.

PostedbyG. Capano
April 25, 2010

Yes, the circuits might look similar, but unfortunately the chip depicted here is not available in the 2001 model’s computers.

On eBay what they offer are mostly resistors in a box, unless they are selling a reprogrammable unit, not just a box with 2 to 6 wires attached to it.

The reprogramming approach for these ecus is different and will include using special hardware and equipment.

April 25, 2010

Okay I think you enlighten me. There are chipa and there are resistors.

Do resistors act the same as chips??

PostedbyG. Capano
April 25, 2010

No, not at all. You will find interesting the following article on this blog:

Resistors Vs Chips



April 30, 2010

wow sweet stuff dude.

Leave a comment



NOTE: Please, use a VALID email above. Otherwise, we will not be able to publish your comments.