Hey all! Ive got misfire and stutter on my 04 5.4L and throwing P0353. I have checked for chafing around accumulator, chanced out the COP connector, zip tied all wires away from the accumulator, swapped out COP. Is the next step untaping the wire harness and following it back to the PCM to check for damage? I found an article on testing the wire and conection with a voltmeter but I didnt understand the termenology. Any suggestions would be greatly appreciated.

 

The easiest way to check is to use a noid light, plug it into #3 coil connector and with the truck running the light should flash rapidly, with out a noid light you can check for 12 volts on the red/light green wire at the connector, the power wire is the same for all coils, the PCM is going to trigger or cycle the ground on the white/pink wire, that is the driver circuit for the coil, but you will need a meter or a light to test that. noid light are not expensive and your local parts store will have them

 

Thanks FT. I will try tonight

 

well the light seems to be flickering as it should but then again it was not acting up at the time I tested it. I got in this morning and it was a really rough idle. Had to get to work so I could not check it. I will wait until tomorrow when it is acting up and check again. One thing I did notice was that when I would put it in drive with my foot on brake, it was stuttering and the interior light with door open was diming with the stutter. Would a bad wire to Cyl. #3 cause this or does that change where I should be looking? I am going to use a ohm meter tmrw to check at conector and ECM to get resistance read but I wonder why my dome light would flicker from a cylinder wire?

 

O,K. so I checked #3 cylinder in this maner

pulled cop connector started truck and measured
AC hertz. got a 3.4. Checked #6 to compare and it was the same.

Checked DC voltage at driver connector to see if any voltage was found. None...so no short to voltage.

Disconnected pcm connector and checked for continuity to coil connector and it has continuity.

Checked resistance between ground and coil connector and it was infinite resistenceat coil driver (white/pink) wire on connector. which it should be.

SO.....Any ideas???? PCM bad for just that cylinder? Cam positioning Sensor or Crank sensor? Throttle body sensor. I have heard these items mentioned as a stretch but do not believe that is it. Please Please. Im out of ideas.

I don't want to get smoke blown up my A#$ by the dealer at $90 but might have to!

 

ya its at the dealer. i will post what they say.

 

I guess all this time #1 had a miss and they do not know why pcm was saying #3. That is what I focused on for 3 days and as soon as I put a new coil on (2min.) #1 it was fine. I had read about making sure to do a balance test on ALL cylinders but did not (idiot). We will see if pcm starts throwing cylinder #3 code again and if it does, dealer says new pcm is in order.

 

i hope that fixes your concerns and you do not need a pcm