Granddaughter just bought my nephews 2010 Mazda 3 wagonwith 140000 miles, he got rid of it because AT light came on and not shifting. Dealership said it had communication codes to trans stored, they sent TCM off because could not get one but that did not fix it, said it needed transmission. Been parked for a year, son-in-law said when cold it goes into gear and shifts up to 5th gear then down ****s to lower gear after AT light comes on. Turn car off and it will manually shift into all gears then let off an AT light comes on and it down shifts to a lower gear but keeps on moving just to higher RPM, any suggestions

 

Welcome ot the forum
Take it to a specialized transmission service shop.

Do not replace any parts before they have shown to have failed. Nothing showed me that the diagnostic was done correctly and there was an assumption (GUESS) to have the TCM rebuilt???

When was the last transmission service done and what was it before the transmission started to have problems?

If you don't know and no one kept service records then expect you are going to get an estimate for a rebuilt transmission.

 

nepew had it to Mazda dealer for the work done, I got a look at the paperwork from their shop which they said it had communication codes which they said they checked connectors and harness and decided the TCM had problems which they had 3 cars waiting on TCM's that were backordered so thet sent his off for repairs. Got it back and car did same thing then they were told to service trans and they drained and put 5qts back in it and NO FILTER. the fluid is dark which I was going to change filter an fluild after I gave someone a chance to answer on here, I dont like throwing parts at something. But I doubt if filter has ever been replaced, good place to start.

 

Re-read my response.

I may add that while I was pointing the results of have a better qualified service shop evaluate you transmission I was being “polite”!

based on all you information the best thing you can is start looking into a low mileage with warranty transmission and then finding a cheap grease monkey to install it. It does not require skilled individuals the RnR a transmission just basic auto mechanical skills.

If you want to know for sure and cheap …send a small sample of the oil to be analyzed. It’s about 30
https://www.blackstone-labs.com

ASE

 

Thanks for answering me, just to get a feel for the service dept at that mazda dealership I checked with all the parts stores to see if the trans in the car uses a replaceable filter, went on line and checked and all show to have a replaceable filter. That mazda dealership told me it was a screen up inside the trans that was not a replaceable filter. Do you know if it is or not?

 

I need the engine size and trim level?

Example of random look up for approx. information you gave
transmission filter part number example:
FN01-21-500A

 

Just so you know, based on what you posted even limited and incomplete so far you have a lot more going on mechanically with your transmission.

ASE

 

thank you

 

Your welcome. I am sorry to be blunt but I have serviced or have had many in the shop from customers and know the signs of a less then a regularly serviced transmission and information . I truly hope I am wrong but that would be pretty rare.

The good news at least in the USA is that there are many business that offered low milage trans mission with a warranty much better cost then a rebuilt or new one.