Coil and ICM Input Test

[Edgeauto]

DIY Coil and ICM Input Test
Disclaimer: The following is provided as a GUIDE ONLY, and neither myself nor Ozhonda take any responsibility for the outcomes of someone else doing the following. You follow these steps at your own risk.

I have notice a few threads with people with no start/cutting out problems, so i thought i would make a DIY article to try help out. NOTE these specs are an average as most models have different specs so if you readings are close they are probably correct.

Undo the 3 bolts and remove the distributor cap. Remove the rotor button, it may have a screw in it if so remove it if not use a screwdriver to gently pry it off. Then remove the leak cover.




IGNITION CONTROL MODULE INPUT TEST

1. Remove the wires from the ICM

2. Turn the ignition switch to ON. Check that there is battery voltage at the wire that came off terminal C and body ground

3. With the ignition still on check there is battery at the wire that came off terminal B and body ground. If there is no voltage test your coil.

4. Check for continuity between the wire that came off terminal D and the ECU

5. Check for continuity between the wire that came off terminal A and the Tacho

6. If all test are normal replace the ICM



TESTING A COIL

1. Grab your multimeter and put it on the Ohms setting. Measure the Primary Windings resistance between the A and the B terminals, it should be about 0.7 Ohms.

2. Now change your settings to Kohms and measure the Secondary Windings resistance between the A and secondary winding terminal C, it should be about 17 Kohms.

[ECU-MAN]

absolutly awsome DIY dude. love your work

this should come in very handy like you said, very common problems start here.

good stuff

[solitz]

good work champ...nice labeled diagrams btw

[ThEbLaCk]

Thanks alot. I haven't tried it yet since the car is fine now after fixing up the relay.

Where are the wiring for the ECU and Tacho by the way?

Nice work champ once again.

[Edgeauto]

Tacho=instrument cluster

ECU=OBD0 pinB15=OBD1 pinA21

[Kaji-FMP742]

Hate to sound like a noob, but if I were driving at 100km/h and the car just randomly dropped power, then picked back up again, I should do this test? I'm running an F22A6. Honda motors are new to me.

[Jazzle]

does it happen only at 100km/h or more?

[dsp26]

+rep for you... even though replaced the icm coz i knew the icm was rooted.. this would have been awesome earlier

however, my issues was getting erratic tach signal at high rpm due to a semi-rooted icm cause by spark leak.

i'm assuming it would have still shown continuity right? or it would have had some sort of resistance?

***EDIT***
oops already repped you a while back and forgot about it

[Edgeauto]

Yes it would still have continuity. A erratic tacho is a tell tail sign of a rooted icm and sometime accompanied by an engine miss too.

[Kaji-FMP742]

... engine drops with the tacho wiggle!

Thanks man! I was scared as hell it'd be some strange unfathomable thing. This forum's already saved me from expense!

[dsp26]

just wanted to add this vid:
http://www.youtube.com/watch?v=qYs67zlcKCo

the faulty over-revving is a result of a dead/dying icm.

Thanks to cristian for taking the vid

[Kaji-FMP742]

That engine sounds delicious.

.. do B20As sound similar? Or should I just continue on my quest to find an H22A Accord halfcut on this side of Australia? (there was one in WA recently..)