2004 Mazda 3 HB - AT problem?

[veblen]

Hello all,

I just got a 2004 Mazda 3 HB w/ 103,000 miles a couple of weeks ago and in the last few days, there seems to be a problem with the AT.

It upshifts fine but once it gets to 4th gear, it does not downshift when my speed drops or when I'm moving uphill. This results in my engine vibrating and I have to engage the tiptronic to manually shift down to 3rd to get extra power. Why is this happening and is there something I can do about it?

Also, when traveling on the freeway at about 75mph, the engine revs to 5000 RPM at 4th occasionally before dropping down to 3000. Is this normal?

Thanks for any help!

 

[chrissor]

could be transmission range switch, but i would lean towards the TSS (turbine speed sensor) it seems that its not reading the change in speed of the torque converter.

 

[vladjan]

i have a 2004 Mazda 3i, 2.0 L engine, i had a very similiar problem with my car. dealer was able to pull the code and that's what was causing it:
ok here is what my record states:
Concern: Cust sates at times "AT" light comes on and car will not come out of 3rd gear (transaxle Light)
Cause: Diganose code P0715
Correction: R & R Turbine speed shaft sensor circuit part retest ok
Part Number : MAZ FN01-21-550

 

[vladjan]

it was like a 120 dollar service including te labor, not too bad considerein i did it on the dealership, but i had warranty so only paid a deductible

 

[veblen]

Thanks for the suggestions!

I brought the car to a trusted mechanic to figure out what's wrong and he came up with a diagnostic code of PO732. It turns out that the 2nd gear ratio is incorrect and he said my reverse gear was shot as well - the scanner showed 4th gear when he put it in reverse. In any case, he told me to keep the engine running and take it to the dealer.

So I did and during the entire drive there, the AT warning light was on, I had no numbers in tiptronic mode and the car shifts really abruptly, jumping from 1st to 3rd gear (the 2nd gear light never came on). At the dealer, they told me to make an appointment.

Now that I restarted the engine, the AT light is off and the car shifts normally though the problem in my initial post is still there.

I will bring the car to the service center tomorrow and was wondering if this is a serious problem (i.e. how much it may cost me) and whether it will be covered by a limited powertrain warranty.

Any advice or recommendations will be greatly appreciated! Thank you!