Re-occurring P1233- FPDM offline.
11-19-2019, 08:23 AM
#1
Re-occurring P1233- FPDM offline.
Hello, I'm hoping someone may have some insight for me as I seem to have run into a wall with this problem. I have a 2006 F-150 5.4. Time to get an inspection sticker on the truck, and I had just replaced the battery, so I obviously needed to drive the vehicle to ready the monitors. Long story short, 02 monitors will not run and I have code P1233 stored, but no CEL illuminated, and no driveability issues whatsoever. I replaced the FPDM with a cheapo unit- code returns immediately when engine is fired up. I did some research, and following wiring, I inspected every connector and accessible harness for the circuit from PCM to the FPDM- no corrosion or any obvious defects. I measured the resistence of the signal wire from FPDM to the PCM pin- .5 ohms. Figured the cheapo unit I bought was garbage, so bought a Dorman unit and installed it- same problem. Only thing left I can think of is a PCM issue, but that seems improbable. Any help is appreciated.
