long read ahead:


Shortly after I purchased my Grand (used but by a very knowledgable and honest individual), the check engine light came on. I had the guy who sold it to me pull the code with his scanner and he got a "Transmission Control Module Malfunction" reading but as the engine light wasn't blinking I decided to continue on home.

On the 600 mile trip back home the EVIC chime sounded about six times and the message "Service Rear Park Assist" came up, followed by the PRND boxes all being boxed out as if every gear was selected. Usually shortly following this but sometimes occuring on its own, the car would abruptly lose all engine power and lurch forward as if it had just downshifted into first. Jabbing the pedal would do nothing for about 3 seconds and then the vehicle would jump forward and everything was kosher again.

Shortly after I arrived back home, the check engine light went off and neither problems persisted. Then it came back on and both problems reared their heads about twice over the course of a week, then the check engine light went back off.

The next day I went in to the dealership (scheduled a day after I got back home, quickest they could get me in) and told them what was going on. The service tech had no idea what was wrong but said they'd check into it. I requested that they flash the computer as I figured that would take care of the problem. When I picked up the vehicle he said that there were no stored codes but they flashed the computer and over the course of a 30 mile test drive ( :rolleyes: ) couldn't get either the "Service Park Assist", engine light, or lurching issue to manifest themselves.

I left uneasy but the vehicle performed fine over the weekend in a variety of conditions. This morning (cool weather, less than 70 degrees, not driving aggressively, sitting stopped in traffic actually) the "Service Park Assist" message came on the EVIC for a second, the PRND all boxed out. Then as my time came to turn, I gave it some gas and the car started to take off normally only to lurch (causing the guy behind me to get a little too close to comfort) and then after a 3-4 second delay began to accelerate again.

I do not want to bring my vehicle back to the dealership that originally could not find the code to have them drive it for hundreds of miles "trying to find the problem" (especially after an acquaintance that works there told me "we drive the piss out of the cars we get here, especially the SRTs and turbod PT cruisers"). I'm at a loss as for what I should do. The vehicle is currently driving fine but this problem is very unsettling and could potentially cause an accident. I vaguelly recall that someone at SRT will entertain these kinds of questions from owners (maybe a PR guy?), does anyone have information regarding this? Has anyone else heard of or experienced a problem like this?

Personally I think that the transmission computer is probably shot but I don't want to go to the dealership (there's another dealer close by that I may try too, but again I don't want the dealership to have my vehicle to beat on and I also want to enjoy my new toy) without knowing whats likely the cause so I can have the process expedited as much as possible with as little "test driving" as possible.

Thanks for any help you guys can provide,
Dave

uhh anyone?

I have had the exact same problem! But the vehicle only lurched wildly once. The parking assist has been going on and off and I have tried cleaning the eyes on the bumper. The lurching happend last weekend and has since been fine. But the parking assist still is flashing. I am also puzzeled and wanted to see if it happened again.

Sounds to me like some wiring is chafing and shorting out somewhere. I had that happen with a Barretta I owned some years ago. It can really cause problems throughout the electrical system.

When the problem happens again I would bring it to the dealer as it is happening,if the is possible

Bring it back for the same thing three times and put it in for lemon law,get an 07 out of the deal,you bought the car its not even a year old and having computer problems,you shouldnt be going through this,I would be a little more aggressive with the dealer.Tell them to fix the problem with no more miles put on the car,or you want a new car.Your problem sounds to me is you might have a short somewhere maybe a wire is grounding out somewhere,you say it happens when your driving, maybe when you hit a bump a certain way it happens.You can also try another dealer that knows how to use the computer there has to be some sort of history code lock so they can see what is going on.Later!

It happened to me when I was coming up a very short semi steep right hander while merging into traffic. Luckily no one was coming up quickly behind me or I would have been rear ended. I am going to take it to the dealer tomorrow.

It happened to me again.... I was at a stop light making a down hill right turn and then all of a sudden just as I pulled out into traffic, it started bucking like a bronco. An example of what is going on is, it feels like a fuel pump going bad. Not say that this is problem but once the transmission is able to shift to second it immediately goes away. This is potentially a huge problem for safety and starting to worry me since it has re-occurred. If you are pulling out into traffic and can not accelerate as on coming traffic is approaching, this could be the makings of a rear end accident.

did you try changing the settings of ESP when this happens maybe there is a short or so but also maybe the ESP is intervening with the system next time it happens try to change the ESP settings it is only for you to get out of the problem but I think you should solve this problem right away as soon as possible because before I had a ZJ and it used to get off all power,engine electrical and everything when I take a hard turn and would stop at all and sometimes it restarts and other times I had to shake the car :) until the electic power came back on and the gauges read again and at last they found that there was a problem in the wirring after about 6 months of disaster.

The reason these intermittant problems can be so difficult is that when you bring it in the car is fine. They may be able to test everything, and have it all test out good because the problem is not occuring at that time. It isnt a matter of just plugging the computer in and doing what it tells you, it doesnt work that way at all. At best a DTC is just an area to start on, or with communications lost faults it may lead you down the wrong path.

I would start with the big connector under the hood between the fuse box and master cylinder. We have seen a few problems like this caused by this connector. You could even try this on your own, wiggle the connector and tug on the wires while somebody watches the PRNDL to see if that causes the problem. Then you could unlock the connector by pushing the button in the middle and pulling the lever open. Check for bent pins or pushed out pins, then relock the connector making sure it latches all the way. A zip tie or two around the connector to make sure stays locked couldnt hurt, and you could just try that to see if the problem goes away.