Engine ECU issues

[RAYSTRASH]

I have a 2009 MRU, I'm having problems with a code that comes up (MID 128 Engine ECU, SID 232 5 volt supply, FMI 4) Inactive #19.

The ecm and wiring harness has been changed, and we are still having the same issue with the same code.

The truck will run fine for a day, the the CEL comes on and it goes in Derate. We have taking it to dealers and 3 party shops with no luck.

Anyone have any suggestions?????

[Challenger]

The electronic fan, boost pressure sensor, intake air temp and humidity sensor are on that 5 volt refrence. If one of those sensors or fan goes bad it can knock out the hole circuit causing the 5 volt refrence code.

Unplug the fan, see if the code changes.

Unplug the boost sensor, see if the code changes.

Unplug the air temp and humidity sensor, see if the code changes.

If the code changes that part/sensor could be the problem.

Other then replacing the fan and eecu, what else has been done? I would assume they check these sensors/parts before replacing the eecu. I've seen more boost sensors go bad then the rest.

[staxx]

The problem is that the 5 volt referance can short to ground for a second and log the fault active , when is actually inactive making it very hard to find the problem . Only take one small bare wire. Check we're the fan drive wires come out and follow back to connection turn wire around and check for wear marks. Also 16 pin connection on drivers side near back side of foot valve have seen crusty pins there before , good luck.