2013 F-350 Multiple PCM faults, sensor at defaults -40F and 4.99v

billbled · November 26, 2019

Hi,
I'm new to posting here - but wanted to see if any of you have run into this scenario before. It's on a 2013 F-350, 6.7L, Mfr 6/13, last VIN is DEB64640. I'm at the NC DOT here in Winston, and it's one of our IMAP trucks (that run Interstates all day helping motorists). Mileage is at 227k-ish.

It came in with the MIL on, the thermometer symbol in center dash on and the "Reduced Engine Power" notification coming up.
We have IDS here since we are a Fleet customer of Ford, so I scanned it with IDS 115.06. It came back with the following faults, all current/present, with one exception (the P040D fault):
U0401:68-0A - HVAC - Invalid data rec'd from ECM
U0401:00-8A - IPC - Invalid data rec'd from ECM
P007D:00-27 - PCM - Charge air cooler temp sensor circuit high
P0118:00-27 - PCM - ECT1 Circuit high
P0183:00-27 - PCM - Fuel Temp sensor A circuit high
P0193:00-27 - PCM- Fuel Rail Pressure Sensor (Bank 1) circuit high
P02E9:00-27 - PCM- Diesel Intake Air Flow A Position Sensor circuit high
P040D:00-64 - PCM - EGR Temp Sensor A Circuit high (Previously detected but not currently determined etc)
P2185:00-27 - PCM - ECT2 Sensor circuit high

Also, running the PIDs - I got temp sensors at -40F and everything was at reference voltage, 4.99v or 4.98v that I checked, such as the charge air sensor and both ECTs, and the fuel rail temp sensor.

I know that's a bunch, but that's what was there. I ran thru the pinpoint test on the ECT faults, pinpoint K, and it came down to the end and told me to correct the short to voltage because I had the 4.99 volts present on pin 1 of ECT 1 & 2. All of the resistance checks from both ECT connectors back to the PCM connector checked fine.

I don't see any wiring short that's causing the voltage to the ECT connectors. I'm thinking the actual problem is inside the PCM.

So here are my questions:
1- Does it seem likely that it's a PCM gone bad? This entire situation came on all at once, not in dribs and drabs over a period of time. It was Ok one day, the next it was in reduced power mode with all the warnings and MIL.
2- Have any of you all run into a similar situation as this?
3- Do Fords have many PCM problems? I come from a BMW tech background (dealership level) before coming to the DOT so I'm relatively new to the Ford arena and still learning Ford tendencies.

Thanks for reading all this and thanks for any pointers.
--Bill

lmorris · November 26, 2019

All those sensors share signal return. PCM connector Pin 4. You most likely have an open or high resistance in that circuit somewhere. The splice is in the area of the main alternator. These also are bad for the harness rubbing on the EGR cooler gaskets.

billbled · November 26, 2019

Thank you! I'll take a look there tomorrow.

Keith Browning · November 27, 2019

Agreed on that advice. The two-wire sensors reading reference voltage indicates an open circuit and with that many sensors showing the same fault then the common circuit is likely open as Leon stated. After inspecting the harness for obvious damage I would disconnect all of the sensors on circuit RE-405 GN-WH: those mentioned and the intake throttle actuator sensor and the CCV connector sensor before testing that circuit. It is recommended to load test and check the voltage drop while doing that... not just test resistance... and you can kill three birds with one stone by performing a wiggle test at the same time.

Generally PCM failures are not common as the modules are very robust. BUT if you are confident that you have tested the relevant circuits and pin fit at the PCM is good then the PCM is suspect.

billbled · November 27, 2019

Thanks for the additional details!

billbled · December 9, 2019

Hi everyone,
I wanted to circle back to this post with the solution to this that we found. Hopefully this will help someone in the future. And thank you all for the feedback and testing ideas. I truly appreciate them.
We did all the wire testing recommended here and running through the pinpoint K testing from the Ford IDS side. Everything ended up pointing to a PCM replacement. (which has always made me nervous.)
Got the new PCM, did the PCM replacement procedure, cleared the faults and the truck was fine, and has stayed fine. I think it really is fixed, since it was a duplicatable problem and the faults were active, repeatable faults and now they are gone.

Thanks again for everyone's help!

Bill