Car jerk at around 50mph, at light up and goes away

[icpeanuts]

Hi,

My 2010 Mazda5 have around 65k miles and for the past 2 days, i am experiencing problem. It happened during my drive home where the car would jerk like it was stuck on on a gear. The AT light would come on and I got the CEL, AT and slippy car light. The code from the reader said u0101 and I can not clear it.

I followed some instructions and remove the - battery over night. The morning, everything back to normal. I was able to drive to work, now on the way back, the car would jerk at around 55 mph, the AT light came up, but it goes away, no CEL or any warning light.

Can someone give me some pointers on what could be wrong and a fix?

I started the car again and the u0101 error code came up.

Where is the TCM? I can not seem to locate it, It seems to happen when I drive, can it be a loose connector?

Thanks for any input.

 

[flcruising]

The TCM is under the battery on the back side of the transmission. Likely it needs replacing, but a shop with a VCM/IDS can communicate with it and tell you specifically.

 

[icpeanuts]

Thank you for the info. The code went away and for the past few days, I am able to drive the car without any issue. Twice in the past 5 days, the AT light would come on blinked and goes away, I do not get the CEL or other error.

I have been driving a lot slower, mostly local traffic under 30 mph. On Highway, I have been keeping it under 55. I will look for a shop with VCM/IDS, does any of the chain store such as Pep boys or Auto zone have that device?

How would I be able to access the TCM? take out the battery and the battery holder or I can access it from under the car?

 

[flcruising]

A mechanic shop would have the proper diagnostic equipment, not an auto parts store.
Yes, remove the battery and holder to get to the TCM. Due to it's location, I suppose it's possible that the elements can get to it and cause issues. I recently greased all the easily-accessible connections under the hood of our 5 because some of the contacts showed signs of corrosion. I suggest you do something similar with dielectric grease, it would not hurt. I also know how intermittent problems like this can be nerve-racking, so even though it isn't misbehaving currently, I would still pull it and perform a visual inspection.

 

[icpeanuts]

OK, as you can see, I am a newbe at Cars.

Can you let me know what connection should be grease?
I know the battery, head lights. Is it any connection that can be unplug should be grease?

I Google Mazda5 TCM, There seems to be 2 different items coming up.

1 - # L5A9 18 9E 1B - side of the battery with 2 plugs

2 - # L39C-18-9E1E - one plug. (This is the TCM?)

Which item is related to the problem I am having?

Thanks for your help.

 

[flcruising]

OK, as you can see, I am a newbe at Cars.

Can you let me know what connection should be grease?
I know the battery, head lights. Is it any connection that can be unplug should be grease?

I Google Mazda5 TCM, There seems to be 2 different items coming up.

1 - # L5A9 18 9E 1B - side of the battery with 2 plugs

2 - # L39C-18-9E1E - one plug. (This is the TCM?)

Which item is related to the problem I am having?

Thanks for your help.

That's the way I look at it, if it has a connector, then grease it. The purpose of the grease is to shield the metal contacts from the elements (oxygen), to prevent corrosion (oxidation). Oxidation = resistance. On a CAN data bus (wired network) which is what the individual modules use to communicate, bad connections lead to bad information, therefore errors.

Now I'm not saying that this is your problem, but it's the simplest place to start, and about the only thing you can do to stabilize the network. And the fact that it's intermittent, leads me to believe it could be part of the problem.

The one beside the battery is the ECM (engine control module), the one down below is the TCM (transmission control module).

 

[kw_da]

Unless the connector is fragile, it doesn't hurt to grease them all with dielectric grease like this (https://www.amazon.com (commissions earned)). Other types of grease may or may not work. Sometimes, just the action of reconnecting the connector wipes enough corrosion off the contacts so that it starts working correctly. On the other hand, with some poorly designed connectors with a lot of connections, you get get different intermittent problems every time you remove and attach the connector.

 

[flcruising]

Yes, that works. I use lithium (not silicone) wheel bearing grease myself.

Something like this would work great - https://www.amazon.com (commissions earned)

 

[icpeanuts]

Thank for the recommendations. I am new to these stuff,

Do I unplug, apply the grease on the connector, plug it back and clean up the excess?

 

[flcruising]

I press the grease into the female contacts with my finger. A little bit goes a long way.

 

[icpeanuts]

Thanks, I have added the grease on all the connectors I can see.

The issue with the AT light still happens.
Usually at idle and at gear 3.

For a newbe, I managed to remove the battery and the battery box, access the TCM (barely)

I did not remove the mount, but used a flat head and unplug the TCM. I put everything back and everything works. phew...

The AT light would come up after driving for 15 or 20 minutes at the low speed (gear 3 or idle). It will drive fine until I stop the car and leave to get a cup of coffee and a sandwich, The AT light and CEL will come up. If I let it cool, the AT light would go away. The scenario repeats.

I am wondering what other issue could this be? Should I go ahead and replace the TCM unit?

 

[flcruising]

Does the transmission still jerk like you described initially?
I would pull the code again and confirm that it is the same U0101.

 

[icpeanuts]

It is the same u0101 code.

It does not jerk violently like before, it is more of a bump now. When the AT light come on idling, I did not feel anything. I drove the car twice. When it happens, I can still feel it when it is on Gear 3 (feels like the Carburetor needs cleaning) and notice the AT light.

When I took out the battery and box, there is a piece metal that blocks access to the TCM,
Also another square metal plate under the battery box. Do I just unbolt to gain full access to the TCM?

I read on another thread, the Center Bolt is what is holding the Transmission in place, What do I need to do to gain access to the TCM? Thanks

Update: Spoke too soon, I went on the highway today and drove around 50 to 65 mph, on the lower end, it did jerked violently around 50 mph, once, gear 5. The AT light came on and off. I got to my destination, parked the car. When I went back to the car, the AT, CEL light came up with the u0101 code.

 

[icpeanuts]

With some help, I was able to access the TCM,

Here is a pic of it, is that a signal that it has been fried?

https://drive.google.com/file/d/0B9VEjB-gSVOuLTVIUGNWSkxjOHc/view?usp=sharing

I ordered a replacement. Hopefully this is the fix,

 

[flcruising]

You can't tell visually if there is damage to a circuit under the resin.
Hopefully a new TCM will solve your issue. Report back here with your results.

 

[icpeanuts]

I want to provide an update and Thank you all for the information. I am lucky.

After installing the new TCM, I have been driving normal for the past 2 days. I hope this is the end of the u0101 error.

Should I do anything else since for the Mazda? I have replace the Transmission Fluid, replace the filter, Clean the pan few weeks ago.

Most importantly, I hope my experience can help another person fixing this problem. The Part that I replaced is L39C 18 9E1D, The part I replaced with is L39C 18 9E1E which is the same module.

With guidance, I did this my self. Thank you Mazda Forum and Google.