Greetings all!

Note to forum moderator: I am relatively new to the forum and I may have posted this in the wrong forum. Please move to the proper forum as necessary. Thank you!

I have a 1997 Honda Accord EX with 4 speed auto. I had a issue with the plastic inner fender coming loose and being ripped from the fender well. The right wiring harness was ripped from its hold downs and some of the insulation was abraded by the tire. I took it to the dealer (about a year or two old) and asked them to replace the harness. They supposedly repaired it. About a year go salt water and slush got into their so called repair and it started smoking. I patched the wires as best I could and I ordered a new harness from the dealer and replaced it myself. Everything is worked great except the AC. I used the electrical troubleshooting flowcharts, for AC issues, in the Helm Manual and found a defective a/c switch. I used a jumper at the a/c switch and still no a/c. I checked the a/c pressure switch, fan control units, fan and ac clutch relays and replaced both temperature sensors in the cooling system. I also checked the a/c diode. I ran point to point continuity checks on all wiring circuits. Everything checks out good. The the flowchart indicates the ECU may be defective. It suggest to swap the ECU with a known good unit. I found an ECU from a 1994 Accord LX with auto trans.

Will this ECU work in my 1997 Accord EX Auto? I know it came from a car with an auto transmission because I unplugged the unit myself. My first big concern is the difference between the LX and EX engine (Vtec in the 1997 and standard engine in the LX). My second concern is the three year difference in the ECU. Do they use different firmware in the rom chip?

Does anyone know of a test kit one may built/purchase to check the ECU? I removed the cover on the 94 ecu and everything appears good. No burns or hot spots. I know resistors and caps break down over time. I would like to test the unit prior to plugging it in. Has anyone used a company that works on ECU units? How expensive and do they have the ability to upgrade the firmware?

Sorry for the long post. Thank you in advance for your kind assistance!

 

No it will not work in your 97. Not without using an OBD conversion harness that is. The 94 is OBDI and your 97 is OBDII. They use different connectors and wiring altogether.

If I need to test the ECU I usually use a pin or needle style multimeter probe to stick into the backside of the ECU connector. Known as back probing. There is a tool that some lucky Honda techs might get to use... It is an ECU test harness that plugs in between the ECU and the wire harness. Very hard to come buy and not easy to build.

There are no upgrades or flashes for the 90-97 Accord ECUs. Only safe bet would be to replace the capacitors. They are one of the main issues with these older ECUs.