Pete M wrote:
background: have been experiencing some sort of limp mode lately that comes on out of nowhere and completely goes away by turning the Jeep on and off. took the Jeep to a chrysler dealership that handles diesels with the hope of simply getting codes from it. they say it might take a day before they can get to it. the next day we get a voicemail that says they pulled 10 codes but now the Jeep won't start at all, just cranks. they insist that all they did was pull codes.
codes:
p0101/p0100 (maf has been unplugged for years)
p0672/p0673/p0674 (the 2/3/4 glow plug circuits)
p0234 turbo overboost condition
p0513 invalid key
p0093 fuel system leak detected
p0615 starter relay circuit (probably because I've bypassed the starter relay with a momentary switch in the cab?)
when I showed up today to check it out, I planned on bleeding out any air that might be in the heater head (that has happened before if it's been sitting for a couple months, but never for only a day) and noticed smoke coming from the heater wires (key was accidentally left in the 'run' position while I was priming if that matters). fantastic. so I stopped all research and decided to head home and regroup and ask y'all for advice on where to start, both with the no-start and the original limp-mode thing.
more background: we've already experienced the steering column no-start issue and installed an aftermarket pin. even with that new pin, the Jeep would occasionally not crank (almost always associated with the sun beating down on the dash). that's why I bypassed the starter relay. been working fine that way for a couple years now. I have no idea if the replacement pin has broken again or not. also the ABS system has been down for a few years now.
The heater element in the filter head likes to melt itself which then causes air to get into the head. My guess is you have air in there. Just unplug the heater wiring for the time being and check to see if there is fuel coming out of that plug around the pins once you do get the air bled out.
My guess is the limp mode may be happening due to overboosting. This is usually related to something wrong with the vacuum control system for the turbo or possibly stuck vanes in the turbo itself.