2003 Gr Cherokee transmission slipping in stop and go traffic?

[xtroll]

Hi everyone. I tried searching the archives with no joy so I'm hoping someone can help. My wife owns a 2003 Grand Cherokee with about 37,000 miles. After about 15 minutes in stop and go traffic, the car shudders from a start position. The tach is spiking which indicates to me that the transmission is slipping versus problems with the engine. The Dealership says "they can't reproduce the problem so there is no problem". Any ideas guys?? thanks, Dan

[ChadEbert]

If it's slipping that badly, the OBD should be recording the issue. Maybe they can't "reproduce" the problem, but is the OBD logging it? Maybe they need to look at that. Secondly, is there another dealer that you can go to? I'd assume it's warranty, correct me if I'm wrong. So I'd ask the dealer if they have looked at the OBD to see if the computer recorded the slippage. Then go from there. Or just wait til the thing goes completely, if warranty still applies! Good Luck!
CME

[dksob81]

what do u mean by shudders,
are u sure it's slipping, it could be a bad CPS (CrankShaft Position Sensor), it determines the RPMS of the engine ,and timing of the Injection and spark, but if you are sure it is slipping - maybe u should have the Filter and Fluid changed in the tranny, it should be done every 30,000 miles.

[xtroll]

Originally Posted by dksob81

what do u mean by shudders,
are u sure it's slipping, it could be a bad CPS (CrankShaft Position Sensor), it determines the RPMS of the engine ,and timing of the Injection and spark, but if you are sure it is slipping - maybe u should have the Filter and Fluid changed in the tranny, it should be done every 30,000 miles.

by shudders, I mean the car moves forward from a standing stop after 15 minutes in stop and go traffic in a series of fitful movements - somewhat like trying to start a manual drive transmission in 3rd or 4th gear. The tach is jumping around during this period which I believe suggests that the transmission is slipping and not that the engine is laboring. The engine was tuned recently by the dealership.

I believe that my wife had the transmission serviced on schedule at 30,000 miles but I'll double check to be sure. When you don't have stop and go traffic, everything is fine.

[dksob81]

ok next time in stop and go traffic, put the thanny in 1st gear, and then put it in Nuetral, then start to go, and c if runs better. I think it might be what u said maybe it's starting off in 2 or 3rd gear.

[Cam7]

It almost sounds like your Torqe Converter is trying to lock up. Has it stalled when it shudders?

[xtroll]

No it has not stalled when it shudders. Took it into the dealership this morning and the read the diagnostic codes. There was nothing recorded. However, the service manager asked a strange question. He asked why was the battery disconnected 40 engine starts ago? The codes indicate that the battery was disconnected 40 starts ago.
My Answer: no one has touched the battery and the original battery is still with the car.
The service manager thought that Poster - dksob81's suggestion about checking to see if it's starting in a higher gear is the tactic to try next time it starts to shudder again. He suspects that it is a manual valve that is hanging up.
I take it in for repairs next Tuesday evening (they're full up with 4 cars with transmission problems until then) so I'll see if we can isolate the problem and try the downshifting into first gear suggestion.

[Myrtle Beach]

Where did your wife take it to get the tranny serviced? Sometimes these quick lubes use cheap fluid or the boneheads working there will even use the wrong fluid. Not sure if thats your problem but it is atleat worth looking into before you take it to the dealer with the wrong fluid in the tranny (then it probably won't be covered under warranty).

[dksob81]

yea Beach gotta point, I would think about having the fluid changed, make sure u use ATF+4. I recommend getting it from the dealership also, not getting an aftermarket brand ATF, like AAMCO - altho I trust them, they say it is OEM type fluid, I wouldn't take the chance I would just get the original fluid from the factory.

and xtroll, I had the same problem when I took my jeep to get the computer scanned for codes, they said it was cleared within the last 12 ignition cycles, I told him 12 ignition cycles, that was yesterday, i started the jeep 12 times yesterdy alone and i haven't d/c'd the battery for about 2 weeks. so I had to pay $30 for them to scan the Computer for them not to come up with anything, I am sure glad I found out about the ignition trick to check fault codes,

[rykrdsfamily]

What is this ignition trick about checking the fault codes?

[dksob81]

well I don't think u can do it on the WJ, but I will give it to u and u can try.

turn the key ON, Off, ON, Off, ON, and leave it on. the Check Engine light will come on then go off shortly, then it will come back on FLASHIGN.
count the FLASHES, the codes will be in double digit form.

CHECK ENGINE LIGHT flash = \
\ pause \ \ = 12
\ \ \ \ \ pause \ \ \ \ \ = 55

there will be a long pause in between codes. like this

\ pause \ \
pause pause pause pause
\ \ \ \ \ pause \ \ \ \ \
code 12 and 55
12 - Power was lost to the PCM (battery was disconnected)

55 - End of fault codes.

code 55 will be the last codes that comes up. and u will get 12 if the battery has been disconnected in the last 50 ignition Cycles.

like I said I dunno if this will work on the WJ's but u can try.

[Myrtle Beach]

Originally Posted by dksob81

well I don't think u can do it on the WJ, but I will give it to u and u can try.

turn the key ON, Off, ON, Off, ON, and leave it on.

like I said I dunno if this will work on the WJ's but u can try.

This will work on a WJ-the codes will be displayed on the odometer. The 55 code isn't relevant on the WJ as the Odometer will display
-DONE-

[dksob81]

ok thanx, I wasn't sure if it would work or not.