My engine light has been coming on a lot lately, then the AT light starting coming on, preventing my automatic transmission from shifting into 4th gear.

Sometimes, I'll be driving and neither light is on.. all of the sudden both will come on and it will shift down into 3rd (not good on I-85). Does anyone know what this is ? and how costly it will be ???

 

find someone with a code reader - or buy one - or head to autozone or similar shop, they sometimes scan codes for free.

But generaly, check your trans fluid and such, could be something like a slow leak.
BTW, what model & year is your ride?

 

Thank you ! I will def. try that..

My car is a Mazda 3, 4 door. 2006.

 

Kendall: Did you ever find out the cause of this problem ? I am experiencing the same thing with my 05 Mazda3 hatch. Dealer said I should change the tranny fluid, but with less than 20K miles on the car it would appear doubtful that fluid could be the cause. If I bring the car to a complete stop, transmission immediately returns to normal again, but check engine light stays on for another hour or so and then it too goes of. Consequently, it does not give me adequate time to get the code read.
Could you email me your response, if any, to Alfisto@ aol.com. Thank you.
G. A.

 

My car does the same thing. AT light comes on, won't shift out of 3rd.. but when I completely stop, it goes off. Aggravating.. I went to Autozone and got some "Stopleak", I believe that was the name. I told them I didn't think I had a leak in my transmission fluid but it wasn't running right. So they advised me to put some of that in it. I did, but it still happens every once in a while. Not as often as it was. I am thinking this is going to be a bigger problem than just transmission fluid. ugh...

I'll let you know when and if I find anything else out!! You do the same!

 

It definitely is not a transmission fluid problem or the result of a leak, so do NOT put Stopleak in there. In all probability it is a computer glitch. With my car, it is now happening only sporadically, fortunately. It happens at no particular time but generally at slow speeds driving in town. I shall let it go for now but if it does re-occur, it is easily fixed by stopping the car. If it does happen again and becomes more of a problem I shall take it into Mazda and have the computer "flashed". This should also take care of any upgrades that may be necessary. Good luck with it.

 

Hey guys, new to the forum.

I'm having the same issue with the AT Light. It kicks on and doesn't let me get out of third gear.

It seems to happen most oftern when I'm driving in this middling speeds in suburbia....almost like it gets stuck in 3rd. I don't think I've ever had it downshift me to 3rd, but if it rides in 3rd too long, it seems to happen. If I get it up to 4th, I think I'm OK.

Anyway, does anyone have any updates on this problem. Kinda glad to see I'm not the only one.

I have a 2004 Mazda3, ~67000 miles.

 

"'m driving in this middling speeds in suburbia." Mine does the same, so do what I do - stay out of suburbia !!!
Actually, it is happening less. Maybe once a month or so, when I visit my daughter in the 'burbs. Best thing to do is pull over to a stop and the tranny will immediately revert back to first and all will be well again. It is definitely a computer problem.
GA

 

Yeah it seems to be a Safety mode for the transmission. Samething happend on my 99 BMW 323i. POS French GM Transmission. The computer kept saying the trans was under a stronger load then it was, i got the trans rebuilt and it was fine afterwards.


Are you able to place it in manual shift mode to get it out of 3rd?

 

Mine generally does not happen under load. Generally at slower speeds around town. It sticks in 3rd. and will neither change up nor down automatically, will not downshift by depressing pedal, and will not work in Manual mode. Only remedy is to come to a complete stop and immediately take off again.

 

The code readers are free to use at Autozone, only thing is they read a "P" Code (ex P121, P0120) these codes are different from what a mazda diagnostic reader would see. But you can look in a repair manual to see a generalized breakdown for the Engine Light. In this case its prolly a trans sensor or multiple ones. If your within your warranty, id DEFINATELY take it in for service. Get the work done under warranty when you can.

Self-diagnostic/self-repair will come down the road.

 

I have issues with AT light as well on my 2006 mazda3i. and my situation.. well, while driving down the I-5 I noticed that my car wouldn't go faster than 65, and my rpm meter would skyrocket each time I try to pass 65. then once I got off the freeway onto the city, I would try going up hill and then it would stick on 4th gear, and at the time I'm going 40 or so, and rpm would skyrocket if I tried to speed up. even if I slowed down it would stay stuck in 4th. I stopped the car, and started it up again, then it's fine, but I'd prefer to find out what the hell's wrong with it.. thanks guys

 

My engine light has been coming on a lot lately, then the AT light starting coming on, preventing my automatic transmission from shifting into 4th gear.

 

The sticking in gear is definitely a limp home mode - the autozone code reader may read something, but it depends where the problem is. The standard readers only read limited systems - like the engine computer, and may not show codes for the transmission or other vehicle systems.
Don't have them clear it, but if they find something you may want to try to fix it. The dealer is able to read all the codes, and much better suited to solve the issue if it's a code in a specific system. They are also privy to recalls, common issues etc...

 

well, my transmission is busted, but repairable.. for 2 grand.. hopefully you guys have better luck. I highly suggest checking your trans fluid if anything. I got a used car a month ago and the owner didn't replace it, and it's 1k miles over warranty.. yay..