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micocoro · May 4, 2009, 03:11 PM

Hello all...

After a current heavy rain, apparently the water made it inside the passenger side. While going home from work on the downslope of a bridge the car died. I had it towed to my house where I began to search the Net for possible causes. On was that of a Bad ECM. Well first I had to find out where it was to begin with. Sure enough it's on the passenger side on floor/kick board. There was a lot of condensate on both ECM and the At. So I disconnected them both and opened them up. No real apparent sign of shorting. I dried them overnight. The next day, I hooked them up and the car did start. The Chk Eng Lt was now on as well as running lean at 3000rpm. I drove it to the dealership for diagnostic (AutoMone did not have anything for '96 or older). The dealership said that both computers were bad.

My question for the group is: If I find the matching serial numbers for both Computers will they work. I mean exact except for probably the lot#. Dealer of course said more than likely will not.

Any and all help greatly appreciated...

TxGreaseMonkey · May 4, 2009, 03:17 PM

If you get an exact part number match, it will work. Consider buying a remanufactured Cardone ECM from O'Reilly Auto Parts. It's less than one-third the price of Hondas' and comes with a lifetime warranty, rather than 1 year. This is what I did 3 years ago and it's still working perfectly.

If the car runs, the ECM may not be bad. What code was thrown? Why did the dealership say the ECM was bad? Something sounds a little bit strange here.

Perform the K-Test on the ECM:

The K-Test: Remove the MAP Sensor connector and turn the ignition switch to ON (not start). Using a multimeter, check for 5 volts going between the MAP Sensor connector's reference wire (+) and ground. As you look at the connector, this is the socket on the right. Really press the black test lead into a cleaned main ECM ground on the thermostat housing. If the voltage is low, it's probably indicating ECM failure. Most failed ECMs will record a fraction of a volt. To me, the K-Test is simple, elegant, and accurate.