hi all,seeing if anyone has any thoughts
got a 92 civic 1.5 commuter car was driving and it quit.no spark. have no voltage at the map sensor terminals but voltage at the coil primary. check engine light is on doesnt go off no code stored though. did blow the 7.5 fuse under hood for ecm. swapped the fuse but still no spark. thinking maybe ecm is shot or realy or icm.anyone else. headlamps work both hi and low beams was in motion when it just shut down.no noises nothing.thanx for any help

txgreasemonkey

In my book, the odds are almost 100% that your ECM has failed. You ran the right tests--Check Engine Light staying on, no DTCs being thrown, and 5 volts not registering at the MAP Sensor connector reference wire. Check for voltage at the Throttle Position Sensor connector, if you want, but I think your computer is burnt toast. Make sure to disconnect the negative battery terminal, before disconnecting and reinstalling a new ECM. Keep me posted.

Anvil02

hey tx thanx for the response i figure its either the ecm or the main relay.any test for the relay,dont hear anything clicking when the key is put to the run position.also with the key in the run position motor off im getting 12 volts at the 15 amp acs fuse in the compartment under the dash fuse, so i dont think its the ignition, car was running rough on number 3 cylinder for a week or so before it went. thanx for the reply was hopin youd see my post got some great info from your other responses.

txgreasemonkey

Remember, test for 5 volts at the MAP Sensor CONNECTOR reference (right) wire, with the ignition ON. Test is between reference wire + and ground -.

txgreasemonkey

If the computer is shot, you won't hear the second relay in the Main Relay work. Main Relay Terminal 8, going to the second relay, is a computer-controlled grounding terminal, which won't allow the second relay to ground (click close), if the ECM is bad. Your Main Relay could test fine, but, if the ECM is bad, then the relay won't work properly. The second relay must click close for the fuel pump to run.

Anvil02

ok must be the ecm then,thanx for the help your the new honda god.

txgreasemonkey

Keep me posted. Consider buying a Cardone remanufactured ECM from O'Reilly Auto, with a lifetime warranty, for around $275.

Anvil02

hey tx wanted to say you were dead on about the ecm,pulled mine for kicks and split the covers to take a look sure enough big blown capacitor with scorch marks around it inside.ill tell everyone with a honda to change it out every few years.sad to a guy i worked with had a 94 coming into work it quit.we talked about it and figured it was his timing belt and he junked it without checking now i think it was probably the same thing.

txgreasemonkey

Yes, you are right on. Many Honda owners are getting frustrated with ECMs, igniters, and main relays that are failing--so much so that they are getting rid of otherwise great cars. Where there's adversity, there is opportunity--especially for the sophisticated car buyer, who knows what he's doing.

Does your Civic run, now?

txgreasemonkey

Heat is the killer of ECMs. There's no cooling, unlike on our PCs, and Honda covers them over with heavy carpeting, to make matters worse. 1989-94 Civic ECMs are also known for electrolytic capacitors leaking.