1997 Civic Ignition Module & Coil Replacement?

[njohnson]

Hey Everyone,

My brother and I believe the ignition control module on his 1997 Civic is going bad. He is going to replace it in the next couple of days, but, he was wondering if the ignition coil should be replaced at the same time? Is it a good idea to replace both?

Thanks,

 

[jayjr1105]

There is a good Eric the car guy video on this and he explains what to look for and if other components should be replaced.

https://www.youtube.com/watch?v=RpJpIWLbi2o

 

[SubyRoo]

If it's in his budget I would go ahead and replace the coil also. He might as well since he will be right there and its just two screws and two wires holding it in place.

 

[nthach]

Before swapping out the ICM, I'd test it - Honda has the procedure outlined in their service literature. They rarely ever fail. The coil is easy but I'm leery of non-OEM parts.

Have the valves ever been adjusted? Might want to do that first on a cold engine. It's an oft-overlooked item on Hondas and can do wonders for driveability.

 

[mk378]

The typical ICM failure is that the engine will work fine for several miles then suddenly stall completely dead and crank but not start. After a few minutes to cool off it can be re-started. Testing during the time that it won't start reveals there is no spark.

If the car does this it's very likely the ICM. If it does something else you should check further.

The coil is prone to blow out and stay dead. A coil bad in this way will make small sparks to a grounded test wire with the cap off, but they aren't hot enough to fire the engine. Firing into an open circuit (bad spark wires or spark wire removed while running) is a lot of stress on the coil.

 

[njohnson]

Originally Posted by mk378
The typical ICM failure is that the engine will work fine for several miles then suddenly stall completely dead and crank but not start. After a few minutes to cool off it can be re-started. Testing during the time that it won't start reveals there is no spark.

If the car does this it's very likely the ICM. If it does something else you should check further.

The coil is prone to blow out and stay dead. A coil bad in this way will make small sparks to a grounded test wire with the cap off, but they aren't hot enough to fire the engine. Firing into an open circuit (bad spark wires or spark wire removed while running) is a lot of stress on the coil.


That is exactly what is happening. He drives for a couple of miles, the engine stalls and after pulling over to the side of the road, it cranks but won't start. After a few minutes, it restarts and then doesn't do it again for the rest of the trip. That is why we think it is the ignition control module.

He was thinking if he should replace the ignition coil while we are replacing the module.

 

[njohnson]

Originally Posted by nthach
Before swapping out the ICM, I'd test it - Honda has the procedure outlined in their service literature. They rarely ever fail. The coil is easy but I'm leery of non-OEM parts.

Have the valves ever been adjusted? Might want to do that first on a cold engine. It's an oft-overlooked item on Hondas and can do wonders for driveability.


Where is this Honda service literature? We don't know how to test the ICM ourselves without it.

 

[Dave9]

Most things like this are online somewhere.

https://honda-tech.com/how-tos/a/honda-civic-how-to-test-and-replace-ignition-control-module-374873

I would not replace the coils as long as they seem to be working, unless you plan long trips where it is likely you'd need to tow it to a shop and pay someone else to fix it... but then you could rationalize at least several hundreds of dollars worth of pre-emptive repairs. At some point if reliability is paramount, it is time for a newer vehicle for longer trips.