[rhajri]

Hi. I have mazda 3 2010. when shifting my car it always shows A/T, I dont see D, N, or R. while going reverse the car shake and then move backwards. I changed the TCM but still the same pronlem

 

[Grendel65]

Welcome to the forum.

 

[Grendel65]

I suggest getting your ECU/TCM scanned using a professional shop grade Diagnostic scanner connected directly to your OBDII Diagnostic connector and get the codes first before guessing anything.

 

[Akmnhg5A]

Hi. I have mazda 3 2010. when shifting my car it always shows A/T, I dont see D, N, or R. while going reverse the car shake and then move backwards. I changed the TCM but still the same pronlem

Read the ODB codes and post back.

 

[Milanomike]

You stated the TCM was changed, was that a rebuilt unit or a new unit from a Mazda dealer. Not all TCM's can be repaired it turns out.

 

[Grendel65]

The problem seemed to have occurred before the TCM change if you read the first post. His quote ["I changed the TCM but still the same pronlem"] unquote. Most TCMs having communication issues for transmission operation will generally have DTC when scanned properly to check for them.
The best advise at this point is what I and Akmnhg5A suggested.

I would recommend not to change at random guessing any parts until a scan has been done.

Mazda as well many auto manufactures have offered for some time both new and tested re-cycled ECUs,PCM,TCMs. very few aftermarkets as well as the used units offered by auto manufactures are actually rebuild them because of the labor time to disassembled and replace failed electronics. They are usually tested for continuity and re-flashed with the most current programs available. A widely thought misconception about rebuilt ECUs,PCMs,TCM!

Unbuildable is another of the widely thought misconception about rebuilt ECUs,PCMs,TCM!

 

[Elefteria]

Sounds like the TCM 4 sure

 

[Elefteria]

Hi. I have mazda 3 2010. when shifting my car it always shows A/T, I dont see D, N, or R. while going reverse the car shake and then move backwards. I changed the TCM but still the same pronlem

- I have the same car and it was the TCM-- I sincerely hope you went to an authorized Mazda dealer and purchased a NEW TCM. As well the location of the TCM was changed in 2010 since prior it was to close to the exhaust manifold , which could cause the wires to melt and the TCM to get fried- It is still in a place that gets hot , so check the three cables that junction at the TCM for any unusual heat damage -- If you do a lot of city driving in a hot place ...it could be the wires - also make sure they are connected properly- it was difficult for me to get leverage to get them connected properly --I had to buy a specific pair of extended needle nose plyers to get the cables inserted all the way -- that was the hard part -- Its under the battery which is easy to remove.

 

[Grendel65]

- I have the same car and it was the TCM-- I sincerely hope you went to an authorized Mazda dealer and purchased a NEW TCM.

There really is not a need nor necessity for a OEM new TCM. In fact Mazda offers "rebuilt TCM,ECU and PCM for some models and years. It just more matters that you purchase from a supplier that will guarantee the unit and will exchange it should it not work.
We change out several dozens of these each year and rarely have problems. As I think I said we also do health checks and Pass-throughs to insure workability. So bottom line you really do not need a NEW OEM unit!

Use your contacts at CS with VT and talk with the techs that deal with ECU,PCM and TCMs.

 

[Elefteria]

There really is not a need nor necessity for a OEM new TCM. In fact Mazda offers "rebuilt TCM,ECU and PCM for some models and years. It just more matters that you purchase from a supplier that will guarantee the unit and will exchange it should it not work.
We change out several dozens of these each year and rarely have problems. As I think I said we also do health checks and Pass-throughs to insure workability. So bottom line you really do not need a NEW OEM unit!

Use your contacts at CS with VT and talk with the techs that deal with ECU,PCM and TCMs.

Without doing thorough hands on testing - its difficult to properly diagnose any issue- being online in a forum has its limitations thus the scope of fix reccomendations differs from popping the hood and getting into it - My personal experience has been that OEM parts cause me far less headaches than gambling on something thats not - When I changed my TCM , I just looked at the code and the mileage - suppose I got lucky , but it dialed everything back in . Can you get good non OE stuff- of course -.but I dont like doing the same work 2x - cutting the odds on that happening - starts with using new OE parts -It eliminates part of the guesswork in the troubleshooting process as well - hope the issue gets resolved at a minimum cost & headache -

 

[Grendel65]

You do realize that a substantial number of OEM parts are now and have been manufactured from outside the OEM and in the private sector for several years now? Some right alongside aftermarket replacement parts.
So, the information of assuming that oem is better than aftermarket as far as reliability or quality is hard to distinguish unless it is an unknown brand of aftermarket parts.
BTW we were talking about ECUs new or rebuilt/re-cycled (whatever the supplier wants to call them) in which all are still 100% OEM only health checked and programed. And in some rare cases an ECU is open and circuit boards replaced. Very Rare.

 

[Milanomike]

Have not seen the PO for a while maybe he/she got it fixed. My experience, yeah, I know a statistical analysis of 1, says go OEM or Mazda rebuilt for this one. Many advertise they can rebuild these, in my case, they could not.

Of course, tough to diagnose online like this as no DTC's were posted.

Hope the PO comes back and lets us know if and how it got fixed just for the record.

 

[Grendel65]

Have not seen the PO for a while maybe he/she got it fixed. My experience, yeah, I know a statistical analysis of 1, says go OEM or Mazda rebuilt for this one. Many advertise they can rebuild these, in my case, they could not.

Of course, tough to diagnose online like this as no DTC's were posted.

Hope the OP comes back and lets us know if and how it got fixed just for the record.

I have a contact that did the actual ECU/TCMs for Chrysler during the 1996-2015 and know what it takes to do a "repair" as he described it. He corrected me that ECU, PCM,TCM are not rebuilt. When they are opened up and if 90% of the components are in specification working, they may repair the fault boards of panel. But it takes hand soldering and labor extensive time for that process. He indicated that the fail rate of repairs like this is close to 50%. The only time most all ECU vendors offer repairing it if obtaining a usable core is hard-to-get.
I have had to a few times for customers to seek out cores with recyclers that are nationwide connected to find an acceptable one. Let me tell you some good health checked cores came to my with cob webs dirt and rust they phisicaly looks like going through a battel zone. Try selling them to a customer. Nope I had to clean them up mask the original VIN and other id stickers and paint them. Even if once installed you could never see them. I suppose I was lucky and did get a good core that proved to be health check positive and only needed a new update pass-through to get it working for the customers vehicle.