QuestionQUESTION: I have a 2002 300M that has a check engine light on and a P0700 code when I have it scanned at AutoZone. I did the on/off/on/off/on with the key and the odometer just said 'done' and "------' no codes where given.
The symptoms are as follows:
The first occurrence was a rough down shift when I was slowing. The car shifted into 2nd gear and would not shift up or down from there. When I made it home, I was close, it shifted hard into park. I also pulled the shifter back into the AutoStick position and all the gear indicators lit up, so that on the odometer the transmission showed it was in all positions, PRND1234, all at once. I shut the car off and restarted and it shifted into drive and park fine and seemed fine. It drove normally the next morning. The car exhibits the same symptoms each time it has an episode, a rough downshift into second, where it stays until I park and shut off the car and turn it back on. After the restart the car will shift normal until it has another episode and down shifts roughly into second. It seems to be happening more often the longer I go.
I have the VIN if that is needed.
ANSWER: Hi Bobby,
The 0700 code means that there are other fault codes stored in the transmission's control module which are specific to exactly what are the causes of this behavior. The Autozone scanner didn't have the ability to read those codes. You would do well to go to a garage that you trust which would have a more powerful code reader which can get those extra codes to readout. Don't do anything further than getting the code numbers, ask what they mean, and ask what they recommend and what would be the cost. Let me know the results and we'll compare that with the shop manual information which I have.
The behavior you describe is called 'limp-in' mode and is a self-protective technique built in to the transmission which purposely shifts it into second gear which because that uses the fewest parts but allows the vehicle to be driven.
Please read the PS below and respond to it.
Thanks,
Roland
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QUESTION: OK I got the codes read at a Transmission shop. P1776 was the code. Some solenoid pack error. The guy said its not uncommon on a car as old as mine. 140k miles. He said the pack needs replaced. Quoted $600 for the job. Suggestions?
ANSWER: Hi Bobby,
I am a bit concerned that the mechanic jumped to the conclusion that the solenoid pack replacement is the only possible solution. There are several other possibilities for that code which should be checked out and which if one were found to be the cause might very well be a less expensive repair: the transmission control relay (an in expensive electrical component that plugs in), an issue with the electrical circuit that controls the Low/Reverse pressure switch sense circuit (an electrical connection issue) or it could be the transmission controller or something else internal to the transmission (which would be more expensive than the solenoid pack itself). I can copy the pages from the '04 transmission diagnostic manual that show how to go through the process to diagnose exactly what is wrong using the reader box and a Transmission simulator tool (Miller tool #8333 and adapter tool 8333-1A). I wonder if the shop you went to wants to try that diagnosis or just assume that the solenoid pack replacement will do the job. I would suggest you ask them about that approach and see if you think they would actually do it. If not or you have your doubts try another shop, asking them what there approach would be to a 1776 code and see what they say (there should be no charge to just tell you what they would do and for how much).
Tell me your email address if you want me to sent those pages. But don't use the @ symbol as that causes the address to be erased. Instead use 'at', and also you can check a box to make your response to me 'private'.
Thanks for the rating and nomination. You are entitled to do both again for this answer is you would care to.
Roland
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QUESTION: Please send me the pages you mentioned. Is there any way I can test the relay or connection you mentioned myself?i am fairly mechanically and electrically inclined. I restored a 68 mustang. Send the scans to Wilson.raATinsightbb.com.
Thanks!
AnswerHi Bobby,
Yes, the easiest way to check the relay would be to switch it with another one of the same part number in the power box in the engine compartment. Choose one that is not necessary for the operation of the vehicle (wiper, a/c compressor clutch) and see if that solves the problem.
I can also send the pages that show the transmission wiring diagrams and you can check the wiring based upon those diagrams for the circuits that are mentioned in the pages about the 1776 code I also will send to you. Let me do that copying tomorrow morning and get them into an email then.
Thanks again for your rating/nomination/kind remarks.
Roland
