Bronco Forum - Full Size Ford Bronco Forum banner

Engine light on Code P1351

16976 Views 4 Replies 3 Participants Last post by  miesk5
Fixed a issue with teh vacum leak my old brake booster was causing. Now I have another code which is

P1351 - Ign Diagnostic Monitor input Ckt

Any Ideas what could be the cause? engine seams to be running fine.
1 - 5 of 5 Posts
Here is the Ford OBDII information

See page 31 for your code. Not sure if it helps much..
If there is not an IDM edge (coil firing) for every PIP edge (commanded spark event), the PCM will look for a pattern of failed IDM events to determine which ignition coil has failed. If the ignition coil cannot be identified or if the engine is running and there are no IDM edges, the IDM circuit is malfunctioning (P1351).

So how do I go about repairing this issue?

Actualy I think I know why the code is coming up now.
Before I did the Hydro brake booster swap I had a engine light coming up for a vacum leak cause my old vac brake booster was leaking. during that time as I was gathering parts stil for the hydro booster I had swaped out the ignition modulle, and it ran fine. looked at the old ignition module and new one and realized the last 2 alpha letters had been both different. I went over to teh dealer and had the parts guy run both numbers and the old one pointed to a different alpha letter as well. So I' waiting for tuesday to get here to get the new one that I need. I read on the board somewhere that thye had created 2 different Ign modules and one sends a signal to the ecm telling it that the spark had fired to the coil.
See less See more
I think you have it solved.
by David S in Motor Service, June, 2001 via

Should be Black in color for the CCD Type Module.
Sorry, filed to add this due to lag by Comcast and I then I over-wrote it.

DTC P1351 Ignition Diagnostic Monitor Circuit Input Fault "...P1351 can occur if the Igniton Module was replaced with the Gray one instead of a Black one. The ICM Should be Black in color for the CCD Type Module. Many Ford parts sources are incorrect and show that this vehicle should have a Grey module. The Motorcraft part number for the Black ICM is a DY-679..."
1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.