I havea honda civic 1993 dx whit automatic , when trying to start I will get crank but not turn over(start) , no fuel or spark.

The engine light will stay on and won't give any code when jumped.

The main relay(mitzubarz-0132) won't "click" when in on position.

Map sensor will get around .32volts with ignition on.

All fuses are good checked twice

Shifterwill not move even with brake pedal press down. (weird).

Ineed some help

Replace the ECM and your problems will be solved:

1. Disconnect negative battery cable, after recording radio codes.
2. Remove right door sill molding, pull carpet back, and expose ECM.
3. Remove three 10 mm bolts and one 10 mm nut securing ECM cover.
4. Separate ECM cover from harness carefully.
5. Press connector release, going to connectors A, B, and D, and carefully pry connectors from ECM, using a small screwdriver.
6. Plug connectors into new ECM and button up.

Remove the old ECM first and be sure to get an exact part no. match.

Why is the main relay not activating ?
Is it because of the ecm?
Or is it because is damaged (inop)?

I am trying to learn in the process of fixing it...

The main relay is not working because the ECM has failed. The ECM controls grounding through main relay Terminal 8. Until I developed the K-Test, this was the most difficult Honda problem to solve--now, it's a piece of cake. Buy a remanufactured ECM and you will have your car running in 15 minutes.

OK that explains a lot thanks soon as I get the ecu I will let you know

O.K. If you buy a remanufactured ECM, shop for warranty as well as price.

I install the ecu starts fine , now I have other problems , I'm getting code 41 oxygen sensor I gess and code 30 A/T FI signal A and I have no idea what to do... any ideas?? I know you do...

Code 41: Replace the oxygen sensor or clean the oxygen sensor pigtail connector with jeweler files. Here's how to replace the sensor:

https://www.askmehelpdesk.com/cars-t...tml#post223376

Remember to stay away from generic oxygen sensors--go with a Denso. Afterwards, reset the ECM.

Could I get you to take the K-Test Poll?

https://www.askmehelpdesk.com/cars-t...oll-51138.html

You are welcome. Good luck.

What is the k test?

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.

Never mind

Thanks for updating the K-Test Poll--it helps other people by chronicalling that Honda ECMs are not "bullet-proof" and that they can perform a fundamental test on their health themselves.

Is your new ECM an exact part no. match to the old one? Is it a remanufactured or new ECM?

After changing oxygen sensor and reseting the computer I still getting code 41 and 30 the car is running normaly... I put red line fuel injector cleaner before changing the old o2 sensor... any ideas

. Did you reset the ECM, after installing the new oxygen sensor?

. Is the new ECM an exact part no. match? If not, this may explain the Code 30.

I have a honda civic 1991 dx/automatic. When trying to start, it will get crank, but not grab (start). I have confirmed no spark to plugs and no fuel coming from fuel tank.

The led code light (on front passenger floor under carpet) blinks once to indicate it is working, but gives no code after that.

This is almost identical to earlier post by 1993 Honda Civic DX .

Solution there was to replce ECM.

Wanted to confirm from TXGREASEMONKEY that the ECM in question is the Engine Control Module or "Computer" of the $200+ variety?

jbrewster321, yes that's it. Remove your old one first and get an exact part no. match.

Dear TX Greasemonkey,

Refresher - 91 Honda Civic DX - Power to starter, no power to plugs, no fuel to cylinders.

Got a used ECM from an auto recycler. MY ECM had the following code on it.
37820-PM5-A80 - Assumed # to match
221-181656 ME - Assumed serial # of ECM
90.9.14. Stamped on the aluminum case

I made sure the 37820-PM5-A80 was matched on the ECM that I got. Installed and got no improvement. CEL comes on for 2 seconds and goes off. ECM LED flashes once and goes off.

Returned ECM for a second one (on basis that it might be bad). Same response with second ECM. Power to starter, no power to plugs and no fuel to cylinders.

Had not thought to listened for relay clicks, but noisy seat belt system has covered up any sound they may have made.

What do you recommend I do next to resove this issue?

Vr

Jim Brewster

Jim Brewster:

. Test all underdash and underhood fuses with a test light or multimeter:

https://www.askmehelpdesk.com/cars-t...tml#post252145

. Clean main ECM ground, located on the thermostat housing.

. Perform K-Test on the ECM:

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.

. Ensure you can hear the fuel pump in the gas tank run, when you turn the ignition switch to ON (Position II). When the CEL goes out, do you hear and/or feel the Main Relay "click"? If not, repair or replace the Main Relay.

. Check ignition switch for wear, pitting, or melting:

https://www.askmehelpdesk.com/cars-t...tml#post224652

. Read and perform tests in the link below:

https://www.askmehelpdesk.com/cars-t...ml#post1245523