QuestionQUESTION: I have a 1992 Grand Caravan 3.3 AWD. When I first start it up, it shifts fine until I travel 3 or four miles. Then it goes into limp mode. Cycling the ignition key three times and counting the check engine light flashes, I get code 12 and code 15.
ANSWER: Hi Stephen,
Do you notice whether the speedometer also stops working? The code 15 says that there is no signal from the output speed sensor of the transmission being received by the PCM. That, if true, would also cause a limp-in of the trans. So that is one possibility as to the problem. The code though is based on the engine controller only. You could also readout the transmission controller via the data link connector under the dash using the Chrysler DRB II or equivalent code reader and the specific plug needed. But if you aren't getting speedo reading, then you might want to check the plug to the sensor which is at the very rear end of the side of the trans that faces the front of the van. If that is OK then replacing the sensor might well be the way to start on this issue. It simply unscrews and the new one should be torqued in similarly to a spark plug (20 foot-pounds). If that doesn't work then find a shop that has a reader and plug that will get you the trans fault codes. Then let me know.
Roland
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QUESTION: I did have a problem with the speedometer being intermittent. I found the transmission ouput speed sensor (just below the trans cooler lines), unplugged and replugged it and that problem seems to have stopped.
ANSWER: Hi Stephen,
That is more likely the turbine speed sensor, not the output speed sensor. Look on the other side of the vertical shift rod for the output sensor which looks the same. I don't think the turbine sensor would affect the speedo, but it's being flaky could cause the limp-in situation. So see what happens...
Roland
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QUESTION: I just wanted to post what I have found. After your last post, I found out that it was indeed the input turbine connector I had reseated. Also, after having originally taken the van to a trans shop where the technician told me there was so much gunk from a leaky power steering unit, and that my best hope was to clean it up and reseat all of the connectors, I degreased and power washed the engine and trans, located and reseated the output speed sensor. I then took it for about a 15 mile drive up and down some hills, stopping and starting. It consistently shifted as expected.
Also, I found yet another power steering leak in the process (so far I have had three, the pump, high pressure line and now one of the rack tubes). (Sheesh!!!).
AnswerHi Stephen,
If I interpret correctly, the problem with the trans and the speedometer are now things of the past. So, thanks for letting me know. Sorry to learn of the power steering unit leakage. Good luck on getting that resolved. It is good that the trans is performing properly as that otherwise is a large cost item. I hope it continues to perform well for you.
Roland
