93 Dodge Intrepid, code 66

Hello,

I posted here awhile back about my problem with my '93 Intrepid. It will randomly drop into second gear and the speedometer drops to 0. It stays this way anywhere from less than a second to around thirty seconds then goes back to normal. The output speed sensor has been replaced my mechanic has gone over everything he can think of. The odd thing is that, up until now, it has never produced any error codes.

After a trip home where it did this 6-8 times, I tried the key trick just for the heck of it. It got 12 66 55. So I took it to the mechanic today so he could check it out with his code reader. The reader said there were no error codes. We tried the key trick and 66 was still there. He was able to look up 66 but is not sure exactly what circumstances would produce this code.

BTW, does anyone have a definitive answer to how long it takes for the code 12 to clear and what specifically triggers it? I think I might have an interruption of power somewhere and the code 12 might also be a clue.

Thanks for any help, DSF

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The diagnostics in the FSM always tell you: verify that the problem isn't one with the connection to the sensor before replacing it. In this case, so many of these sensors fail that it's reasonable to shotgun it and just replace it first. But now that you still have the same symptoms, it's time for someone to start taking a real good look at the wire and connector that go to that sensor. Bet the problem is in there.

--Geoff

Reply to
Geoff

Code 66 means that the body computer or transmission computer has not communicated with the engine computer for at least 10 seconds via the CCD bus. causes for this include; an open in the CCD + circuit an open in the CCD - circuit a failed PCM no power to the transmission control module a failed transmission control module

Reply to
Neil Nelson

I appreciate the response, but the first paragraph of my message was meant to bring anyone replying up to date. The speed sensor was replaced months ago. Since then pretty much everything involving the sensor and it's connections has been gone over.

Thanks, DSF

Reply to
Audiofile

Thank you for the info. The part about the 10 second interruption is very interesting. Although I said above that the effect can last anywhere from less than a second to around thirty, I'm beginning to think that most times it's shorter than it seems to be. (When you're driving at highway speeds and it drops to second gear, it can seem like a lot longer time!) I believe one of the most recent occurrences passed the 10 second mark, which is why there have been no error codes previously.

I think the best possibility might lie with the last two reasons you listed. I like the "no power..." reason better since it's probably the cheapest. Let me toss a scenario out there and see if there are any faults with it. The TCM loses power. Since the TCM drives the solenoids in the xmission, any that are on turn off. I would assume that leaves the xmission in 2nd gear. It would make sense to design it this way: no power=limp mode. The output speed sensor feeds the TCM. Since the TCM is dead, no forwarded signal for the speedometer, etc. Power returns < 10 seconds: Everything returns to normal. Power returns > 10 seconds: The PCM reports error 66.

How does that sound?

DSF

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Audiofile

Reply to
mic canic

Sounds like time to pull the PCM and TCM connectors and do some cleaning.... as well as double-check all the ground strap connections.

Reply to
Steve
[snip]

You've got it.

Reply to
Neil Nelson

Thanks for the comfirmation. Any idea which pin(s) (or wire color(s)) on the TCM connector is used for power?

DSF

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Audiofile

{snip}

Thanks. That's one of the first things I did. No help. :(

DSF

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Audiofile

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