ChewX4

Hello. New to the forum, but I've been reading through the various posts for quite a while. I have a 2012 Ram ST Dually, which I bought used about a year ago. It was a one owner truck with great service records and had 98k on the odometer. Randomly, it will decide to go into limp mode. I've taken it in to the dealer several times. So far they have done a software update on the computer, replaced a loose sump filter in the tranny, and replaced the wiring harness that connected to the exhaust system (I was getting several 02 sensor related codes). The truck seems to run great, except for the intermittent limp mode issue. I'm not getting any other codes. I've talked to a few people and they believe it's related to the DPF system. I try to "run it hard" on the highway when I can. Only once did I get a Regeneration message, which indicated 90% full. I ran it on the highway for 45 minutes and haven't seen it since. Yet, I still can have it go into limp mode. The limp mode doesn't last long (30 sec to a minute) and I can usually make it quit by either putting the car in park or by shutting it down and restarting. Just wondering if anyone else has this issue and if the DPF is likely the culprit Thanks!

johnh

how would it be to have a truck with all the emission problems that i don't have?

Busboy

I was going to suggest pulling the transmission pan and having a look in the bottom, clean the pan and replace both filters, but you say the dealer was just in there so all should be good, I would however check the transmission fluid level. A momentary transmission fault will put the truck into limp mode and can reset itself. It could be an actual fault or a wiring problem like a internally broken wire touching end to end or a pin pushed back in a connector. The transmission wires go through one of the multi pin connectors by the drivers front wheel well and while they are sealed connectors the rear of the connectors are open to the elements and corrosion. They are also a known problem with pins being pushed back.

ChewX4

Thanks for the suggestion, Busboy. It's been frustrating as otherwise the truck runs great. I do plan on doing he stealth DPF delete, mainly just to be rid of the regen headache.