Stuck in 4th, but evap code also, then ok.

[rotwiler]

Last night I put some molded mud flaps on, put truck in reverse, when in D, noticed power was low, then saw 4 on dash and engine light on. Stopped on side of road, tried restarting and still was in 4, then after like 10 attempts was in Drive again, but 5 minutes later went back into limp mode and into 4th gear. So I went to dealer today, check engine light was on, but truck was shifting ok. Noticed eco mode was not coming on and auto start won't work. So dealer said they are booked up until Jan 2, 2018. I had them pull codes and came up P0750, which I expected, but odd code P0441 evac purge came up. Truck has never thrown a code before, so odd both came up at same time. So I thought, maybe will just get gas cap, I had filled truck day before when it went into limp mode, but had driven 30 miles with no code. So stopped at auto parts store, put new gas cap, started truck and there was no check engine light, truck drove normal and eco mode worked. Now I didn't start truck and let it idle before check engine light went off, instantly when I started it, was off, so I am confused if that was the issue or just coincidence that light went off at that time. Any suggestions appreciated. I only have 3 months left on power train warranty. Truck is 2013 Ram 5.7 QC, 2wd 6 speed.

 

[rotwiler]

Only thing I did that day when both codes came up, is fill gas tank, went to carwash with touchless jets, does underside of truck too. Drove 30 minutes, let truck sit 3 hours, when I backed out and put in drive, was in limp mode. Anyone ever experience odd codes from carwash getting pcm wet? Now truck cleared codes and is normal.

 

[rotwiler]

Now tonight it threw a code p0204 injector circuit cylinder 4. So now I have on scanner, P0750, P0455 pending, and P0204. Any ideas? Pcm maybe?

 

[ColdCase]

Some of these faults will remain active until three fault free ignition cycles, some reset immediately. So trying to correlate independent faults can get confusion. Just use the scanner. Remote start isn't going to work with most active faults. You will stay in limp mode until there is an ignition cycle. After an ignition cycle, normal operation is resumed.. until a fault is detected. Sounds like you got water in a connector or component.

Those three are pretty much unrelated except its the PCM that sets them based on electrical inputs. So perhaps one of the PCM connectors is damp, or the PCM, or you have a lose or bad ground somewhere. These signals all seem to go through C3 and C4, so its not just one connector.

 

[rotwiler]

Ya, 2 cleared, went off for about 24 hours then the transmission code and Injector code came up at same time. At least now truck is in D.