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Randall C
Randall C, ASE MasterTechnician
Category: Ford
Satisfied Customers: 12803
Experience:  35 years ASE Master Tech, Diagnostic , Electrical Specialist
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Ford F150 I have a 2001 Ford F150 with 2wd 4.2L V6. The engine

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I have a 2001 Ford F150 with 2wd 4.2L V6. The engine shakes badly after putting in gear ( automatic Transmission) , Seems to idle fine. Truck does not respond to acceleration. Seems to be held back. I took to auto parts and had the code reader pull codes from check engine light. Codes showed Ignition coil B failure and both banks lean. I have replaced the o2 censors , i have changed coil pack, spark plugs and plug wires already. Now the only code showing is the ignition coil B failure. Help, cant seem to find problem

Tracer :

Hello, My name isXXXXX will do my best to assist you. I am working with your question now. Will return shortly

Customer:

Hi Randall

Tracer :

the coil as you know is one piece. There are 3 different circuits within the coil as ABC with B being the middle one for 2 cylinders. On a V6 if you drop 2 cylinders, it will barley run off idle. The diagram below clearly shows the 3 wires directly to the PCM. The PCM controls each internal 2 plug coil so... you have one not working. Since you did the coil? you are left with one of 2 problems. Either the wire on middle coil is bad to PCM Or more likely, you have a bad coil driver for coil B within the PCm meaning a new PCM would be needed

Tracer :

The dark blue/ green wire should be the coil not firing

Tracer :

the lean code? really is not meaning the engine running but rather the PCm detected a rich condition forcing the engine lean. this will happen if 2 cylinders not firing

Tracer :

meant " running lean"

Tracer :

Rich because 2 cylinder not firing but fuel still going into cylinders

Customer:

the truck has some miles on it and i kind of enjoy learning about he engines so i replaced some parts as i was trying to figure this out. Can you buy and replace the PCM?

Tracer :

Yes,, they are offered for your truck as reman at local parts store or new through dealer. remans are just fine and cost much less

Customer:

how difficult is this process, I am not a highly skilled mechanic but i do have ability to do basic repairs. I dont want to make things worse.

Tracer :

The PCM is under the hood, right side, back near firewall. One 10mm bolt heat holds the big plug of wires to it. Disconnect battery, undo the plug, remove the PCM. Not too difficult. It is a rectangle box of sorts about 10"x6"

Tracer :

powertrain control module

Customer:

if I continue to have problems after I replace the PCM, any additional suggestions ?

Tracer :

first you would want to check the wire from coil to PCm with ohm meter. or have someone do this. if ok? then suspect PCM. really not much else as you did the coil which would have been first thought

Tracer :

hate to do this. I have to run down street an pickup "munch" :) my German Shepherd puppy at doggy daycare. I will be back online within say 1/2 hour if? you have any followups. have to get him by 5:30. I promise to be back shortly if you need me. Thanks

Customer:

ok , thanks , I will save conversation and get to work. Thanks Randall

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