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sprinkles08, Chrysler/Dodge/Jeep master tech
Category: Dodge
Satisfied Customers: 22526
Experience:  ASE Master and Advanced Certified, Chrysler/Dodge/Jeep Master Certified, Trans and Hybrid Specialist
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I have a p0354 code which means no. 4 ignition coil is defective,

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I have a p0354 code which means no. 4 ignition coil is defective, i've replaced it and nothing happens. performs the same.

Hello and welcome to JustAnswer!


Which side of the engine was the coil replaced on? Was it the left (driver's side) or right?


Customer: replied 7 years ago.
Driver side. I replaced the ignition coil driver side middle. Also replaced spark plug. When motor is running, I pulled the wire to check if motor was going to idle roughly, it did not then checked compression on all six cylinder, no. 4 had only 60.we checked the obdll and still shows same error code P0354.

Do you have a test light to do some electrical testing?

What were the compression numbers on the other cylinders?


Customer: replied 7 years ago.
all except the the #4 cylinder were averaging 95, no. 4 was 60.

Do you have a test light to do some electrical testing?


Customer: replied 7 years ago.
the mechanic had one and there is current passing through, could it be electrical someplace else? the windshield washer works, the wipers don't, the radio works, although ther's no audio. you think they're connected?

The other problems aren't related.


I didn't know a mechanic was working on it, I had figured that you were. Do you have the car now or is it still at a mechanic? If you have the car and a test light I'd like to do some testing.


Customer: replied 7 years ago.
It's parked like seven miles from my place. The mechanic is off till Monday. What would you want me to do next?

Do you have a test light and want to do some electrical testing, or would you just like some possible causes?


Customer: replied 7 years ago.
Just instruct me and/or possible causes. I hope it's not the cylinder head nor the engine. Please advise.

This code sets when the control circuit for the number 4 ignition coil isn't a complete circuit from the ASD relay through the coil back to the engine controller (PCM). It may or may not be related to the (possible) low compression that was found. We need to look into the electrical circuit first.


Start by disconnecting the number 4 coil and find the dark green/orange wire in the connector. Attach the alligator clip end of the test light to ground, use the probe end of the test light on the dark green/orange wire. Start the engine and see if the test light lights up.


If it doesn't that means there is a broken wire that we'll have to find.


If it does light up then attach the alligator clip of the test light to battery positive and probe the other wire in the coil connector. Start the engine and watch the test light, it should rapidly flash while the engine is running. If not, then there is either a broken wire or the coil driver is burnt out of the PCM. The next thing we would need to do from there is go right to the PCM and check the coil driver there.

Customer: replied 7 years ago.

how do we check the coil driver in the PCM? test light also? i might take the car back with me. the mechanic insists on the low compression issue. i know they're out there to make money, but I've spent enough for penalties and other fees from the DMV. So the last thing I want to hear is there is a problem with the motor.

Since we have this fault code set I'd like to pursue it first before telling you it's time to open the engine up. Normally this code is just an electrical problem, but once in a while and obscure problem can happen where a misfire can set coil or injector codes. 60 psi on one cylinder when the others at 90 is a problem, but alot of variables can go into a compression test and niether of us where there to see it done.

We're checking the coil driver by attaching the alligator clip of the test light to battery positive and probing that second wire in the connector. If we find it to be not flashing then we'll go right to the PCM. If the wire isn't shorted to power or ground and it won't flash right at the PCM then the PCM can be condemned. It's not unheard of on these cars for a coil to fail and actually take out the coil driver requiring the PCM to be replaced.

Edited by sprinkles08 on 6/12/2010 at 12:26 AM EST
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Customer: replied 7 years ago.
Thanks for your help. Unfortunately, needs a new cylinder head. it was rediagnosed with no. 4 cylinder, low compression and a bunch of other codes stating that there is a major problem with it.

Sorry to hear about the bad luck. Thanks for the update, and good luck with your car!