Originally Posted by MtnDewJoe

Unfortunately this problem continued to happen. They tried tightening up the pins again, and before they even bent anything they were able to get it working again simply by disconnecting the sensor connector from the top of the transmission and reconnecting it, then tightened the pins/sockets again for good measure. It worked fine for a few weeks, then back to its old ways (AT and Check Engine lights on, hard shifts into reverse).

Most recent is that they replaced the "E" solenoid wire. It's still working fine, but if it goes bad again, next step might be to replace the entire wiring harness, which won't be cheap. Not just that connector - The entire harness all over the engine.

I know I'm kind of talking to the wind, but hopefully someone will find this information useful someday.

Originally Posted by Mazdagrl5

Hi everyone. All my weird symptoms were attributed to my fuel pump goin out on me. Car wasn't getting enough fuel to push out rpms. This is an expensive part so I ordered mine online At advanced auto parts for half the price That the shops were trying to charge me. I paid for labor only and it's been running good ever since. I hope this helps. By the way the diagnostic is an overnight process you would have to leave your car

Originally Posted by Skeller777

Hey I had the Same problem as you, to fix the problem just simply replace or clean the your fuse box first before you replace the harness, unplug all the wires and take the bolts of from the fuse box pull it off and check under the fusebox and I think u will find some corrosion, clean it off or if its very bad than get a new fusebox, if its looks good than replace the harness but I think u gonna have problem with the fusebox cause unfortunately water passing trough there do to the bad design and it gets corroded, but before u take the fusebox out u can do a simple test start your car and try to move the whole fuse box and see if the car stop running or check engine goes on or the gear light start flashing or disappear that's should be a sign for the fusebox problem, so Good Luck!

Originally Posted by MtnDewJoe

This has been a great car for me but I'm at the end of my rope with this one. Maybe someone here has some insights before I pour more money into it.

I have a 2006 Mazda 3s sedan, with the 2.3L engine and automatic transmission.

Back in December there was one goofy shift around 2nd gear which caused the AT light and Check Engine light to come on. I took it into a local transmission shop that seems reputable, and they checked all the easy stuff (sensors, etc) and said the problem must be internal, and wound up rebuilding it for $3700. They said it had a bad servo, whatever that means.

After the rebuild, the CEL and AT light weren't on anymore, and all appeared to be well except for a few oddball shifts that I attributed the transmission "relearning". But then around New Years, the AT light came on again, shifts from first to second revved too high, and putting it from park into reverse was a violent affair.

I took it back to the trans shop, still under warranty, and they found that there was a blown fuse. Here's their diagnosis:
"Shifts great 1-5 gears. Cel on. AT light on. Arsh reverse engagement. Scan tool displays no codes in PCM, TCM, and KOER. Install quick scanner. Does not power up. Try another techs scan tool. Indicates it has no power to DLC connector. Check wiring diagram for DLC. Fuse panel under passenger kick panel. Fuse F47 10 mini fuse blown. Replace fuse, still no codes. Start vehicle, all fail lights are off and has normal transmission operations."

Relief, right? Well a few weeks later it started acting up again - Violent shifting into reverse. This time I checked Fuse F47 before bringing it to the shop and it was fine, so I brought it back. They had the pan off, checked a bunch of things but said the solenoids and everything in the pan checked out OK, and it was a wiring problem and not covered by warranty. I told them to halt and that I would take it to the dealer, which I did. Trans shop's notes say:
"Code Po471 TCC performance or stuck off.
P0771 Shift Sol E performance or stuck off.
Clear codes. Immediately come back. Hard fault. All solenoids ohm. Fine through trans connector.
P0745 Shift Sol A hard fault occurred once."

Took it to the dealer and provided them with the above info. Dealer's diagnosis:
Checked and found codes P0745 and P0733. Checked pressure solenoid and shift solenoid 'E'. Tried to actuate solenoids with scan tool, would not actuate. Checked connector at transmission, appears OK. Possible TCM problem. Would like to remove transmission pan and check connections at solenoids, estimate of 1085.00.

Having already spent $3700+, and knowing that they wanted to replace the TCM, I knew I could replace that with relative ease for about $150 so I figured that was worth trying before letting the dealer rack up four-figure charges. I got a TCM from a nearby salvage yard but unfortunately installing a different TCM made no difference.

I can take it back to the transmission shop, who knows the history of this particular car pretty well now but not Mazda3's overall, or I can take it back to the dealer and pay and arm and a leg per hour with no assurance that even thousands of dollars worth of work will result in a fix. Has anyone else come across anything like this? I came across one similar tale on here where the TCM replacement appeared to solve it, but unfortunately that didn't pan out for me...

Shifting into reverse is still rough - I've been driving in such a way so as to avoid using reverse at all times. Downshifts from 5th to 4th can be slightly clunky sometimes, as is coming to a stop. Upshifts are generally good with the exception of 1st to 2nd, where the RPMs sometimes go higher than they should.

Any thoughts are appreciated. Thanks in advance.