New to the forum, I have a 2001 Supercrew with 5.4. Truck was running great until yesterday. P0352 code tripped. Replaced the coil, same issue. Thought the new coil was garbage, took it back and bought the more expensive one from O'Rielly, installed it and same issue. Thought the connector might be the problem, replaced that, same issue. Anyone know what might be going on? I have owned this truck for a year and it has been a good truck so far. Scratching my head over this one though. What have I not looked at?

 

Move the coil on cylinder 1 to cylinder 2 and see if the code moves to cylinder 1. Did you check the spark plug? You can also check the hertz of cylinder 2 with a multimeter. Could be bad ecm.

 

Bad PCM. Sounds like a lost ground in the PCM.

 

I didn't try moving the coils but I did go around and unplug them. There was a difference in all of them except #2. The spark plug looked good. I used my multi meter but had it on ohms. When I replaced the coil it read the same as the others.

 

If it were a PCM issue wouldn't I have a problem with all of the coils then? Does the PCM have a ground strap?

 

The PCM has individual coil/injector drivers for each cylinder.

 

Try swapping injectors, noid light both injector and coil to check PCM signal, check compression. Do it in that order, you'll find the problem.

 

Guess I should mention it is possible to get two bad coils out of the box. Specially if they weren't Motorcraft. So you might want to swap coils before preforming a compression test..it's easier to do.

Also with the noid, -usually just check injector signal with them but, they work for coils as well (COP). Coils will have a lower volt signal vs injectors so the light will blink dimmer that's all.

Never plug a noid directly into your harness connector if it isn't a flat blade. You can ruin/deform your harness connector. Use a clip jumper (short jumper). Crank the engine, the noid will flash as the PCM grounds.

 

I didn't know that. Okay thanks I will check into it.

 

I will try the steps you mentioned above. Seems like I need to become a better mechanic. I am used to old school stuff. Either way I will be learning a thing or two. Sounds like I can rent a noid light, and I have a compression tester. I will try those and let you guys know. Thanks for all of the good info !