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Transmission problem

I posted about this a while back but I have new information now and the old thread seems kinda dead, so here goes…

Hi, I recently got the transmission replaced in my 2001 Mercury Sable. I opted for a used part rather than a new one. Anyway, ever since, the “transaxle” light on the dash flashes occasionally (it’s a gear wheel surrounding an exclamation point). It seems like it usually blinks when I go from 2nd to 3rd gear, but it doesn’t do it consistently.

The mechanic who replaced my transmission didn’t know what it was and suggested I take it to the dealer to get it hooked up to their computer. I ended up taking it to Aamco, whose computer said the problem was “P0713 - Trans Flud Temperature Sensor High Input.” The transmission shop said I should take it back to the mechanic who installed it. My mechanic says it’s just an electrical issue and shouldn’t affect the car’s performance. He said if I want, he can put in a new transmission (the current one is used - I’d have to pay the difference to replace it with a new one). He won’t put in another used one, though, because he says he can’t guarantee it won’t have the same issue. Two questions:

1) Is it really safe to drive the car while this alert is still going off?

2) Is my mechanic being straight with me?



I think most people are waiting for “transman” to come through and give the definitive advice. In the meantime you really want to find out what the actual trans temperature is. It is possible that whatever measures the temperature is wrong - in which case there is likely no problem except that if your trans does overheat for real then you won’t get the warning.

If the trans fluid is actually getting too hot then you will damage the transmission.

Out of curiosity - what was wrong with the original transmission? Did you happen to have a check engine light or any other warning light that you ignored for a while? The thing is that your transmission has “cooler lines” that ship the trans fluid through the radiator to cool it. You could have a cooler line or radiator problem that is not cooling the transmission properly. It is possible that it killed the first one and it will then kill this one.

Whether your mechanic is being straight with you or not, no one can say. Not all mechanics can figure this out - b/c most are not transmission experts. Transmissions are a fairly specialized area (which is why transman would be the one you need to hear from. In the meantime my ramble will bump your post).

Thanks for the reply. The original transmission just cut out suddenly one day. There were no warning lights or change in performance. It just stopped working entirely and didn’t engage at all. My mechanic (who apparently is no transmission expert) concluded immediately - and without much investigation - that it needed a whole new transmission. That’s how all this started. Thanks for the info. Hopefully, transman will throw in his two cents too!


It sounds like your wrench is being reasonable about the issue. He’s going to be eating something on the redo. It’s why some mechanics include a bunch of standard “you pay” upgrades when they do a job. They don’t want comebacks. You can have a never ending story with some jobs done on the cheap …like air conditioning in a 12+ year old chassis.

It sounds like the wire to the temp sensor has a poor connection or something. I find it unlikely that the trans would primarily heat up in the 2-3 shift. That sound like a trans mount/motor mount puts stress on the connection or something. The condition wouldn’t appear and disappear that quickly. It would have some duration to it.

Well, do we know for sure whether the trans is running hot or not?? Your mechanic should try to find out if the trans is actually running hot. The transmission oil temperature sensor is pretty simple. Why does your mechanic want to replace the transmission?? I would replace the sensor first, its only an $8.00 part.


Well, I’m getting the impression that my mechanic doesn’t know much about transmissions, which is unfortunate, because he’s the one that installed mine. I think he only knows how to remove and install them, not work on them. He offered to replace mine with a new one without charging for labor, but I think that may be the best he can do. Should I take it to a transmission place to replace the sensor and find out if it’s running hot? I don’t think my mechanic would know how. Either that, or he just doesn’t want to. I don’t know.

Thanks for the help!