P1968 and a few other problems any suggestions?

My 99 Caravan (3.3 liter flexfuel) failed emmisions this week. The failure was caused by code P1968. Accodring to one source "there is no digital data communication from the the transmission controller OR from the body controller." I had a problem with the gages dying and the ABS light coming on. Also there is a beeping alarm that I believe is the key in the ignition warning, I can't lock the power locks when the alarm is beeping..

Last night I pulled the panel and looked over the connections and the parts under the dash and when I disconnected one of the smaller terminals from ther switch the alarm would go off and I could lock the doors with the switch on the drivers door. I don't remember which terminal it was.

I suspected the ignition switch was the cause of the gages dying so I replaced it today. My gages had been dead for over a day and they have come back on. I still have the beeping and I can't lock the power locks with the key out of the ignition when it is off.

I disconnected the battery and the check engine light went out. I haven't been able to check for codes but my resident emmisions expert says they aren't there if light went out it will pass the smog test so I will give it a try tomorow.

Does anybody have any suggestions?
George

My 99 Caravan (3.3 liter flexfuel) failed emmisions this week. The failure was caused by code P1968. Accodring to one source "there is no digital data communication from the the transmission controller OR from the body controller." I had a problem with the gages dying and the ABS light coming on. Also there is a beeping alarm that I believe is the key in the ignition warning, I can't lock the power locks when the alarm is beeping..

Last night I pulled the panel and looked over the connections and the parts under the dash and when I disconnected one of the smaller terminals from ther switch the alarm would go off and I could lock the doors with the switch on the drivers door. I don't remember which terminal it was.

I suspected the ignition switch was the cause of the gages dying so I replaced it today. My gages had been dead for over a day and they have come back on. I still have the beeping and I can't lock the power locks with the key out of the ignition when it is off.

I disconnected the battery and the check engine light went out. I haven't been able to check for codes but my resident emmisions expert says they aren't there if light went out it will pass the smog test so I will give it a try tomorow.

Does anybody have any suggestions?
George

code P1968. Accodring to one source "there is no digital data communication from the the transmission controller OR from the body controller." I had a problem with the gages dying and the ABS light coming on.





So... what was the fix?





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Loose pins at the instrument cluster. At the time I posted the question I didn't have it figured out. I tweaked the tims a little to get a good connection.

Loose pins at the instrument cluster. At the time I posted the question I didn't have it figured out. I tweaked the tims a little to get a good connection.


gkbiv,

Thanks for posting back - I fiqured at the time you had NOT fiqured it out, and once you did you had forgotton "where" you had posted the question -(Allot of people on the net posting on muliptle boards with such questions)

The reason for my post being I fiqured by now you had:

A) Fiqured it out
B) Would get e-mail notification
C) Post back the "fix" which may prove helpful to others.

You are to be commeded for posting back as allot of posters ONLY care about their problem, not realizing that with a future problem they may benifit from persons that have "posted-back" the "fix".



Another reason I posted was I have a 98 Dodge Grand Caravan with the 3.0 Mitsubishi 6G72 engine which has been experiancing almost identical symptoms.

In my case it appearing it being a bad connection at the TCM (Transmission Control Module) .... either that of the TCM is dying...
A tip off to this may be:

Gauges jumping, and or dying
The indicator which displays what gear you are in NOT responding to commands. (Move gear shift and displayed gear does not correspond)

In my case a tip off to it being in the TCM circuit being the above- and I would notice if I moved the gear shift and got a non-responding condition that several seconds later the gauge cluster would die.

Upon inspection I noticed what appeared to be ATF in the area where the multiplug for the TCM connects at the transmission - so my TCM may not be long for this world..

Related to the TCM- Anyone here know if the TCM can be done "in-car"? I assuming the TCM going bad does not TOTAL the tranmission, eh?

Another related question for those that may have replaced the TCM (Transmission Control Module).... as I will probally be going to a junk yard for the replacement (Yes I know why they call them "junk-yards")....

I was wondering "what" goes bad on the TCM (I'd rather repair the one I have to tell you the truth - reduce the chance of getting a bad one)


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Loose pins at the instrument cluster. At the time I posted the question I didn't have it figured out. I tweaked the tims a little to get a good connection.

Wow. A raritiy, especially after seven months. Better that than never. Thanks for posting the fix.

WeAreNotAlone - Another culprit could have been the Transaxle Range Sensor (TRS). It is the sending unit on the tranny that sends gear position to the indicator and other destinations via the TCM. A bad TCM can take the tranny with it but, generally a TCM change will fix many transmission problems. Make sure you get the same part number TCM at the junkyard. Yes, there's risks with junkyard parts but, they have fixed many vehicles too. What goes bad in a TCM? It's a solid state device full of IC chips and integrated circuits not normally repairable unless you have electronics training and can troubleshoot to the component level. An oscilloscope helps. Not impossible but, generally not done. What specifically fails? Call a repair facility.

RIP, thanks for posting- somehow I did not see your post. UPDATE (INFO for those having CODE P1968, trans not shifting properly /Gauges Dead, tach dying, jumping): Since my last post(s) 98 Caravan has been trouble free. "Fix" or problem area was the connection at the TCM. In my case no parts required, (loose/bad connection at TCM). That is until today 2011-05-04.... replaced the airfilter (LOL).... and the gauges died again.. Must have "bumped" the wiring leading to the TCM. Pulling on the main harness- that feeds into the harness that leads to the TCM and the gauges are working... at least for now... (Great fix, eh?) *************************************** TCM=Transaxle Range Sensor (TRS). It is the sending unit on the tranny that sends gear position to the indicator and other destinations via the TCM