p1200 (injector circuit)

**Jomamma** · 09-04-2013

Code p1200 (injector circuit) popped up a few weeks ago, and my random misfires in cylinder 3 seems to be missing more often. It only really misfires at idle and while cruising on the highway, where it sometimes misfires up to 60 times.

I tested the resistance across the injector on cylinder 3 (~14.5ohms) and compared it to a cylinder thats not missing, ~14.5ohms again.

I noticed I had a small crack on the top of my maf sensor. That couldn't have anything to do with p1200, could it?

My spark plugs need to be replaced, but that still wouldn't fix p1200.

Any ideas what can be throwing this code?

1997 GTP.

**Jomamma** · 09-05-2013

Maybe I'll try swapping around that injector see if the misfire moves.

**FordMan77** · 09-06-2013

Swap would be a good start.

Try looking over the main harness and the harness to the injectors. I've seen this issue when wiring gets chaffed and corroded somewhere in the harness. It may be back in the harness further from the injector itself so look closely (like back to where the harness runs around the radiator support).

Other possibility is that the ECM is shot.

**Jomamma** · 09-07-2013

I did inspect the harness by the injector. I'll try looking by the rad support.

**GTPWINDYCITYBOI85** · 09-10-2013

i have this same code service engine flashing let me know if you figured it out i have a 97 gtp

**Scottydoggs** · 09-10-2013

Originally Posted by GTPWINDYCITYBOI85

i have this same code service engine flashing let me know if you figured it out i have a 97 gtp

most of the time a tune up can fix a flashing cel. (ever do a tune up?) flashing cel means you have a clogged cat or a ignition problem. (multiple misfires)

**GTPWINDYCITYBOI85** · 09-10-2013

yea i had a tuned like a week i had a p0302 code it cleared that code now i just have this p1200 they say its my number 2 fuel injector but i tried to swap nothing change or do i need to just buy a new one i notice on morning starts smoke come out the tail pipe on start up

**Seachicken** · 09-10-2013

a p1200 would mean that a incorrect voltage level is detected on a injector driver circuit for at least 5 seconds.

misfire history counters can be usefull in determining which injector circuit is faulty. Largest value stored in misfire history may tell you the location of the faulty injector or circuit. If harness checks ok, injector may be breaking down.

a flashing cel is telling you that your engine is running poor enough that it will ruin your catalyst

**GTPWINDYCITYBOI85** · 09-14-2013

where is the pcm located somebody told me i could have a bad pcm causing the p1200 code and cylinder 2 misfire does anyone have a pic of where its located

**Scottydoggs** · 09-14-2013

open the air filter box, its hiding inside there.

**Jomamma** · 10-10-2013

Finally got around to swapping the injector.

Still mostly missing on the same cylinder.

I really don't want to tear apart the wiring harness. Anything else I can check?

**GTPWINDYCITYBOI85** · 10-14-2013

Originally Posted by Jomamma

Finally got around to swapping the injector.

Still mostly missing on the same cylinder.

I really don't want to tear apart the wiring harness. Anything else I can check?

let me know if you find out what causing this mines still doing the same i change the injector my cylinder 2 still misfiring and still have the p1200 code if cylinder 2 only misfiring does that means thats the cylinder the bad fuel injector is on?

**Jomamma** · 10-14-2013

In my case it's not the injector that is causing the problem. It has to be something else with the injector circuit.

My guess is it's something in the wiring harness.