1993-1995 Accord – Prelude Performance Chip Installation
This applies to the following Honda ECM computers: P0A, P0B, P0C, P0H (OBD-I), P11, P12, P13, and P14.
Installing a performance chip on 1993-1995 Honda Prelude and 1994-1995 Accord is a single procedure that consists of removing the stock chip, soldering a 28-pin DIL socket in its place and inserting the performance chip on the socket.
Unlike the OBD-I Civic ECM and Integra ECM, the OBD-I Accord and Prelude ECMs do not require the installation of extra parts other than the performance chip. It has a stock chip that can be replaced, making it simpler in a way, but tougher at the same time in another, because you will need to desolder the stock chip, which is held in place with soldering at the top and bottom sides of the circuit board.
This job requires average skills on electronics soldering, but you can always bring the computer along with the performance chip to any TV or electronics shop, so they can install it. All connections should be verified before and after soldering the 28-pin socket. Take care not to bridge connections with soldering or brake circuit traces by over heating the circuit board with soldering. The parts are mounted on a multi-layered circuit board, which is sensitive to excesive soldering heat. Always clean the finished job with alcohol and inspect for potential connection problems before installing the 28-pin socket.
Your Honda Accord and Prelude ECM is located at the passenger’s side kick panel. After locating the ECM computer in your vehicle, remove the bolts that attach it to its place and carefully disconnect the wiring harnesses that are plugged to the ECM terminals. The wiring harnesses can be disconnected by pushing a plastic clip, located on top of each one of the connectors and pulling it back carefully.
This installation is needed only once. Then ypu will be able to pull out one chip and insert any other, every time you want to switch between “Stock” and “Power” modes. These instructions cover all 1993 to 1995 (OBD-I) Honda computers that are listed at the top of this page for Accord and Prelude.
For installing the chip, just find the 28 pin chip marked as “M38256AP-xx” (see the picture bellow). It must be unsoldered and replaced with the 28-pin chip socket, and then the new performance chip could be inserted on it. Make sure that you align the chip so pin #1 goes to the same place of the old chip (lower left corner of the chip in the picture bellow). No other parts are needed on these models. After inserting the chip, just put the ecu back together and reinstall it in your car.
Note: The “xx” after the “M38256AP” is different in every computer. It is the code of the program written inside the chip. The picture below is an example of the Honda Accord’s P0A-A51 (F4). For P0B it will be “F5”, for P14 it is “C8”, and so on. So before buying a performance chip, you should first open the ECM and check that number to make sure the chip will fit your model, as every ECM has its own code.
Every ecu has its own code. Even the Prelude’s P13 have 4 different codes, which are “A6”, “E6”, “C2” and “C3”. On this case, the code depends on the Domestic Market of the ecu. SO, A6 and E6 are Japanese (JDM) and both programs are different. C2 is for the USA ecu (USDM) and C3 is for the UK European ecu (UKDM or EDM).
One good technique of removing the chip, though still requires patience, is soldering all the pins one by one, putting excess new soldering, so solder will come out easier when using any vacuum desoldering tool.
Never use a soldering irons above 35 watts with these ECMs to avoid destroying circuit copper traces and connections and damaging the chip internally. Always apply soldering flux to the area to be worked out, before starting any job on the circuit. It will greatly help doing the job, as it cleans and rejuvenate soldering when heated.
After finally removing the old chip, you must clean the area with alcohol and remove excess soldering by using desoldering copper braid and then check the whole are for broken traces of potencial connection problems before you solder the 28-pin socket in place.
If you need a copy of the old stock chip for any reason, like for emission tests, you may contact OtherDeal.com to order it. Just drop a quick message at the contact form with the details on what you need for a quote on the item and shipment prices.