1988 – 1991 Honda Civic / CRX Performance chip Installation

This is for the following Honda ECM computers: PM6, PW0, PR3 (OBD-0), and PR4 (OBD-0)

Installing a performance chip in a 1988-1991 Honda Civic/CRX is simple: remove (desolder) the stock chip, solder a 28-pin socket in its place, and insert the performance chip into the socket.

These instructions are similar to the instructions for installing a performance chip on OBD-I Accord and Prelude ECMs elsewhere on this website. Unlike the OBD-I (1992-1995) Civic and Integra ECMs, these OBD-0 (1988-1991) ECMs do not require extra parts. These already include all the parts you need, as a stock chip is installed from the factory. You need to replace the chip. That way, it is simpler but also tougher, because you will need to desolder the stock chip, which is held with solder on both sides (top and bottom) of the circuit board, since these are multilayered circuit boards.

Please note that this job requires average electronics soldering skills, but you can always take the ECM and performance chip to any TV or electronics shop to have it installed for you. Verify all connections before and after soldering the socket, ensuring no accidental solder bridges jump any connection and no circuit traces break from overheating during soldering.

Also note that connections above, below, and inside the circuit board (multilayered) are sensitive to excessive heat during soldering. Always clean the finished job with a mild solvent, such as 91% to 99% isopropyl alcohol.

Your car’s ECM is located in the passenger-side kick panel or lower dash. After locating the computer in your vehicle, remove the bolts that attach it to the chassis, and carefully disconnect the wiring harnesses plugged into the ECM terminals. To disconnect the wiring harnesses, push the plastic clip on top of each connector and carefully pull it back.

This installation is needed only once. Then you can remove the chip you are using and insert any other chip whenever you want to switch between “Stock” and “Power” modes. These instructions cover all 1988 to 1991 (OBD-0) Honda computers that are listed at the top of this page for Civic and CRX.

To install the chip, find the 28-pin chip marked “M38256AP-xx” (see the picture below). Desolder it and replace it with a 28-pin DIL chip socket, then insert the new performance chip. Make sure that you align the chip so pin #1 goes to the same place as the old chip (lower-left corner of the chip in the picture below). No other parts are needed on these models. After inserting the chip, just put the ECM back together and reinstall it in your car.

Note: The “xx” after “M38256AP” differs between computers. It is the code of the program written inside the chip. The picture below is an example of PM6-A09 (65). For PW0, the code will be “71”. For the OBD-0 PR3, there are two versions, “58” and “93”, so before buying a performance chip, open the ECM and check that number to make sure the chip fits your model, since it can differ among similar models.

One good technique for removing the chip, though it still requires patience, is to solder each pin one by one, adding excess new solder so it comes out more easily with any vacuum desoldering tool.

Never use a soldering iron 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 you’re working on before starting any job on the circuit. It helps a lot, as it cleans and rejuvenates the solder when heated.

After removing the old chip, clean the area with alcohol, remove excess solder with desoldering braid, and check the whole area for broken traces or other potential connection issues before soldering the 28-pin socket in place.

If you need a copy of the old stock chip for any reason, such as emission tests, you can contact OtherDeal.com to order it. Just drop a quick message at the contact form with the details of what you need for a quote on the item and shipping prices.