left my truck sitting pretty much all winter. Drove once a week or less to keep it well. Today is the first time I took it out for some real towing, helping a neighbor haul some 10K LB logs. While it's pulling the trailer on a hill, it started to act up like lost some cylinder and power. The "service engine soon" light came on. Now I parked it on level ground and try to figure out what's going on. I have the DP F6 Infinity scanner on the truck and it read: Mil status is off; DTC code =P0381 glow plug / heater indicator circuit and P0475 exhaust control valve.

couold it be just some electrical? I can handle that if that's what it is. Would I be concerned about the engine or cylinder mechanically since it's running rough? help please. Thx. Erwin

 

Sounds like an issue with your EBPV. Have you checked to see if the butterfly valve is sticking? Maybe just from sitting all winter.

 

Thx. I agree. it's probably that. I ran some tests: buzzing, cylinder balance tests. All pointing to #2,4,6,8. must be the connector. The reason I was so nervous and a little upset is that my neighbor started the truck and pulling the load himself. It probably has nothing to do with him, but you always wonder when things happen when you are not the one behind the wheel. I'll stick to my guns never let anyone else touch my trouch from now on. Erwin

 

California truck? I would have expected a P1316 code.

Not familiar with the DP scanner, but I assume it will pull all the engine codes and not just OBDII codes since the OBDII codes look like all you pulled.

Either way, UVCH connector sounds like a great place to start. You can test the pins with an ohm meter if the truck is still in it's acting up phase to check for a loose connection or bad glowplug.

 

Sounds like the UVCH to me as well. With what I have experienced the passenger side is the first to go but get teo new harnesses. About $60 each side IIRC. Depending on their condition, also be ready to get new valve cover gaskets too. They can be reused but depending on condition or if one cracks or burnt pins etc.

Also check the wiring harness that goes over the drivers side valve cover. That is known to rub through and short the wiring on the underside. Just disconnect and check the wiring to be sure there is no excessive chafing.

 

If you have a scan tool, clear the diagnostic trouble codes from memory, and see if the P0475 code returns. If it does not return, then faulty connections are most likely the issue.

If the code does return, you will need to test the solenoid and its circuits. Usually there are two wires at the Exhaust Pressure Control Solenoid, and you must first disconnect the harness going to the Exhaust Pressure Control Solenoid.

With a Digital Volt OhmMeter, connect one lead of the meter to one of the solenoid terminals. Then connect the other meter lead to the other solenoid terminal. Please note that it should not be open or shorted.

Next you will need to determine if you have 12V on your Exhaust Pressure Control Solenoid power supply circuit. Make sure that your ignition is on. If you do not see 12 volts to the solenoid, or if there is 12 volts when the ignition is off, you will need to relay to the solenoid or repair the wiring to the PCM.

 

super frustrated! couldn't get the thing running well enough to move the truck, not much time to work on it. a cummings 4bt engine for my backup chipper is still on engine stand to be finished (forget it, will finish the coming winter then!). work gets very busy too this month. Have to get it running soon so I can at least move it out of the way and do an extensive maintenance later on. feels like my head is going to explode and can only think in circles!

took off the valve cover on the passenger side today. did all the measurement, all good, no burnt connectors. did not open the driver side. measure the pins. glow plugs measure well. buzz test did not come back with any wiring problem to any of the injectors. The engine will start (takes a few more seconds the usual), just runs rough and dies in a few seconds.The only code is P0476 exhaust press control valve. I kind of doubt it. even it stays shut, it should not die, just lacks power.

 

unpluged the drive side, start. unpluged passenger side no start. Now pretty sure something wrong with driver side.

 

found it, AND no surprises. driver side pin common to the 4 injectors. new parts ordered.

 

I was going to say, 2,4,6,8 is drivers side valve cover. But you found it. Glad to here it.

 

Glad you found it!