P0715 and replacing the transmission

girmann

Member
Okay,

So I had the dreaded P0715 code about 4 months ago (3 times in 3 weeks). Took it to the dealer and they said that the sensor was OK, but the transmission was shot. They said that the trans is usually $3000 and without any haggling, they said they would give me $1000 off. I've never known a dealer to do something like that, so I was a bit suspicious. Something in my gut told me something was wrong.

I decided to check the sensor myself and replace it if necessary. The sensor checked out marginally ok, based on the check procedure by wrench. I replaced the sensor and everything was fine for 3 months. Three days ago, I had the transmission slip from 4th to third, the AT light came on and so did the CEL. I'm thinking my transmission is cooked. I haven't checked, but I'm pretty sure that the code is going to say P0715.

I followed the dealer's recommended trans fluid, but did use the automanual quite a bit.

So my question is twofold - one: if I get a new trans, how likely is this to happen again? If likely, then would it be less expensive to convert it to a manual?

Thanks for your help!

Oh: it's a 2005 Mazda3Sport 5 door(hatch) 2.3L automatic
 
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Don't know where you are, but if you have any transmission shops in your area I would take the car to them for an opinion and estimate of repair/replacement cost. It would usually cost less at a local repair shop.

Switching to a manual is rather involved, you need a clutch with all hydraulics, pedal, flywheel, some electrical parts and perhaps a different ECU (not sure about the ecu).
Of course you need a transmission. I would think it would be more expensive to switch unless you can do all the labor. It may be difficult to find someone willing to do a conversion.

If your car has high miles and needs any other work you may want to consider replacing the car.

Welcome to the forum.

Clifton
 
Hello - I also have a Mazda3 hatchbk 2004 with automanual and about 68K mi, replaced the speed sensor two years ago when I got the AT light 51K mi. Also, had trans flush service done at 58K mi. Fluid level is good. Lately AT has been stomping hard from 1st to 2nd gear when engine is cold (warms up within a mile and never comes back unitl next morning). Has anyone else experienced this and is it a bad omen? THX.
 
Hello - I also have a Mazda3 hatchbk 2004 with automanual and about 68K mi, replaced the speed sensor two years ago when I got the AT light 51K mi. Also, had trans flush service done at 58K mi. Fluid level is good. Lately AT has been stomping hard from 1st to 2nd gear when engine is cold (warms up within a mile and never comes back unitl next morning). Has anyone else experienced this and is it a bad omen? THX.

It's normal for it to shift hard from 1st to 2nd when its cold. It's called shift shock and I believe there was a software upgrade to help with it but not get totally rid of it.
 
Question and update:

Question: someone around here mentioned that they fixed a loose wire and their P0715 codes went away. A whole bunch of Google searches and I can't find it anywhere. If anyone has a suggestion or link, I'm all ears. I ask because I'm getting all kinds of electrical weirdness now and am wondering if it has anything to do with the wiring.

Update - Had the transmission input speed sensor replaced by a transmission shop and the fluid and filter changed. Still getting the P0715, although it didn't happen for 3-4 months after getting the sensor changed. I'm not sure what all this means. Dealer said at the time that the transmission could leave me stranded at any point in time. There are a few stories on the internet saying exactly that (it must be true, it's on the internet!). However, the problem doesn't seem to be getting any worse, and I'm now 9 months since the first AT light.

Oh, and I gave up on replacing the auto with a manual...
 
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Update from mid-November: Someone told me to start using the automanual more often and work up to 50% usage rate. Used it only intermittently before. Have done that and the shift shock has disappeared except on the coldest mornings (below 10 F).
 
I have a 04 RX8 Automatic....is the Input Speed Sensor located IN the transmission or on top? I have read that it's on top but the dealer says it's IN the transmission.

Any help, greatly appreciated!!
 
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