Fault code for multiple cylinder misfires

[BuckyB]

Picked up my 2018 transit connect 24K miles with a salvage title due to it was caught in a low level flood. Since I’ve had it if you run it under load uphill in sport mode in 4th gear about 3500-3750 RPM the check engine light will blink and if I keep my foot into it it’ll derate briefly and get my foot out of it power, AC all come back and logs a check engine light for multiple cylinder misfires. I can tell when I’m driving it normally it’ll stumbles like it’s missing but never logs a code and it doesn’t do it all the time just here and there. I’ve changed the plugs, coils, camshaft position and crank position sensors with no improvement. When it stumbles it never logs the code which makes me think something is wrong with the PCM. Buddy of mine thinks it’s a ground issue with the injectors, but again I’ve put 17K on it and has never broke down. 

[Don Ridley]

You need a scan tool to read the DTCs. DTCs will log even when a check engine light (CEL) won't illuminate.

 

Also, the main engine contol ECU, the power control module (PCM), is located low on the front of the vehicle. It can easily get submerged. IF the water leve was about 12" inside the vehicle, the body control module BCM under the glove box could be submerged. But engine problems are most likeley associated with the PCM.

 

 

Edited April 25, 2022 by Don Ridley
PCM info

[Fifty150]

8 hours ago, BuckyB said:

24K miles with a salvage title due to it was caught in a low level flood.

 

8 hours ago, BuckyB said:

I’ve put 17K on it

 

 

 

After that many miles, and whatever amount of time, it's probably electrical.  Whatever got wet, is probably now corroded.  Corrosion can be anywhere.  Inside one of the car's many computers, or at the electrical connections.  I would start by inspecting the connections.  Look for obvious signs of corrosion.  I know.  The car is full of wires, and they all have connectors everywhere.  The car's computer operates the car based on information collected from sensors.  Those sensors also have electrical connections which could have corroded.  A lot of trouble.

[G B L]

A good wiring diagram with all the plug locations will be a great help, pull clean and wd-40 every plug  you can find.