QuestionQUESTION: My vehicle is a 2002 Chrysler Town and Country with a 3.3L engine. The vehicle has approximately 130,000 miles on it. I don't know if the transmission oil and filter have ever been changed (I bought it used). Yesterday, with no previous problems, a loud whine started while I was driving at about 45 miles per hour. At first I thought it was an ambulance siren. One mile later, the transmission stopped working as if it were in neutral rather that in drive. I stopped the car, turned it off and restarted. It drove for about a mile and then the whine came back and it stopped working again. There are no permanent codes and the check engine light is off. I hooked a scanner up and there are several pending codes- P0700, P0731, P0733, P0734, P0841 and P0846. The transmission fluid is at the proper level. The transmission does NOT enter the limp mode. What should I look for?
ANSWER: Hi Tom,
The 0841 and 0846 speak to there being a problem with the 2-4 and OD pressure switch circuits located in the solenoid pack. I would inspect the wiring harness to the solenoid/pressure switch pack on the side of the transmission that faces the front of the car (plug is oval with 8 wires) and the plug proper for any signs of damage. If none, then changing that switch pack out would be the next step. It is located on the side of the trans and is held in place by 3 vertical bolts and you first remove the air cleaner, then the input speed sensor just above the pack, and finally the bolts and the pack.
The 731,733, and 734 are about errors in the input/output speed ratios. These can be related to the speed sensor(s) themselves being defective or could indicate damage internal to the transmission that would prompt a removal/rebuild. Perhaps changing out the pack will solve the ratio problem, so try that first.
Perhaps before even doing that you might want to drop the pan and inspect for mechanical debris in the transfluid/filter which would be a sign of internal failure. You could then replace the filter and about half the fluid which would drain out when you removed the pan. Also check the valve body located just above the filter for loose mounting bolts. If that is not found, nor mechanical debris, and the fluid is not burned or discolored badly, then the solenoid pack replacement would be next. Finally the speed sensors could be replaced.
I am surprised that it didn't enter limp mode (driving in 2nd gear only) as that is supposed to be prompted by each of those codes. It may be that the trans relay switch contacts are stuck in the closed position so you might want to check that relay (2nd socket from the front/outboard side) between pins 30 and 87 which should be 'open' when tested for continuity with the relay removed from the socket. Those pins are the rear/inboard, front/outboard when in the socket.
Please 'rate/nominate' my answer/me (see the PS below).
Thanks,
Roland
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QUESTION: This is a follow-up for the benefit of others to see. I replaced the filter and fluid this evening. Afterwards I drove for about 10 miles and the problem seems to be completely solved. The other steps above will help in the future if the problem reoccurs. This is the second time that Roland has answered for me (2 different vehicles, one in 2011 and his advice is great. I will go and rate him next.
AnswerHi Tom,
That is very good news! I hope that it resolves the problem, but if not, since only about half the fluid was changed you might try it again so as to dilute further the old fluid.
Thanks also for the rating/nomination and kind remarks.
Roland
