94 F150 5.0 shut off suddenly while driving. Towed to me. I have PIP signal to ICM. ICM has good ground, all grounds are good. Coil has 12v to pos and neg side. Crank engine, pos side is steady as well as neg side, no blinking. Replaced ICM, no change. Removed spout, no change. Unplugged PCM, no change. Tried coil bypass test by gounding PIP wire with test light, can't get coil to fire. Replaced coil, no change. I'm at a loss now, I've watched every youtube video and read all the archived posts and not sure where to go now. Any help would be appreciated, Thanks.

 

No ideas huh?

 

Are you getting any trouble codes?

 

Did you check to see if the distributor is actually turning with the cap off while cranking? Just thinking it could be a sheared pin on the gear. If it is sheared, there could be other problems like a locked up oil pump.

 

Dist is turning, I have a good signal to the ICM from the PIP. I have not checked for trouble codes yet. I've been concentrating on finding the source of the no spark issue.

 

Sounds like a wiring problem going to the ICM.
Check all voltages at the ICM.
Check to see if the wire between the coil and the ICM pin is open.
Check to see if you are getting power on the ICM power pin.
Leave the PCM unplugged until you get spark back.
Do you have a Black ICM?

 

Sounds like the coil to ICM wire is broken.

 

Subford, can you give me the correct values at each pin on the ICM to answer you questions?

 

Back probing the ICM plug with the distributor and PCM unhooked and the key on for all test below.
Top pin #1 PIP = zero volts DC. This pin only will have battery voltage on it with the distributor hooked up with the PIP blocked by the shutter and the key on.
Pin #2 SPOUT = zero volts DC
Pin #3 IDM = Battery voltage with the Ignition Coil plugged in and zero volts with the Ignition Coil unplugged from its two wire connector.
Pin #4 Battery power = What ever you battery reads ~12.5 VDC.
Pin #5 COIL = same as the power you will read at the coil NEG (-) terminal, close to the reading at pin #4.
pin #6 Ground = zero volts and low resistance to the battery NEG post.

Note the color GRAY in the below diagram refers to the color of the plug and not the ICM that is Black in a 1994 F-series truck.




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Thanks, I'm not near the vehicle at the moment, but there may be an issue with pin #5 which would make sense. IIRC it had low voltage like 1-2 VDC. Negative terminal on the coil has a full 12VDC. Not sure what that means.

 

I edited the voltage in post #9 above.

 

Thank you so much!

 

It means that your coil to icm wire is indeed broken somewhere, or the coil negative connection is corroded.

 

Ok, so everything checks out except pin 3 and 5 both showing 1.2 volts. If I momentarily ground the negative terminal of the coil, the coil will fire, so the coil is good. Does the wire from the negative terminal of the coil run directly to pin#5? It seems this wire may be broken and the source of my problem.

 

Yes it goes right to the ICM.
But you might have a problem at C101.


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