QuestionQUESTION: I have an 2005 dodge magnum rt with 119k miles, recently I filled up at a nearby gas station started driving home and the car went into limp mode. It was wet and very cold out the day it happend. Once I got home I checked the codes thru the ignition dance and none were showing to be the tramsmission. All were throttle related. I was told the throttle body had to be replaced so I replaced it, once on I drove the car a few miles everything worked fine, later that evening I took the car out again and it went back to limp mode. So then I replace the battery and the throttle pedal with sensor thinking that would fix my issue. Again same result, after a lot of research I decide to replace the ecu, so I got a reman and flashed ecu, again same result it worked fine for a few minutes then it just went back in limp mode. This all happend with out throwing codes. I have now given up and its in the shop, they are telling me I need a new throttle body which I have already replaced. I have told them to check the transmission out because I think that is the only issue. It's not showing any trams codes, where should I go from here? Sometimes the bas light will come on with the etc light.
ANSWER: Hi James,
By Ect light you mean what? Is that the check engine light?
Limp mode is of course the transmission only running in second gear. The codes for the trans have to be read via the socket under the dash as it will only readout engine codes via the odometer window.
If there are indeed no transmission codes but it is doing "limp" mode, then I would think it might be the transmission control relay itself, because that not activating is what limp mode is, only it is done for a purpose when such a code is recognized.
Which transmission do you have: the 4- or the 5-speed as the wiring for the relay differs.
Roland
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QUESTION: Sorry etc light (lighting bolt),and it's a 5 speed. It's currently at Firestone they have plugged up a scanner to read the codes but none are transmission codes.
AnswerHi James,
That lightning bolt light is about the electronic throttle control (ETC) but so far I haven't found a description of what might be the implication/cause of that and whether or not it would affect the transmission. In any case, when the light goes on it should have caused there to be trouble code stored in the powertrain control module memory.
The transmission control relay is powered from the ignition switch and from the switch the current goes through Diode 1 located in the power distribution box at the rear of the car (at the corner of the end of that box which is just opposite of the remote battery post) and from there through fuse 37 in that same box. So if you are in trans limp mode with no trans fault codes I would check diode number 1 and fuse 37, and if those are alright then try switching out the trans relay with another one of the same part number in that box which is not critical for functioning, and see if that cures the limp mode.
