How did you fix it??

Explaining the how you broke down the diagnostic process is a big help. But like Smitty below, as soon as I'm staring at an issue, I forget every video I watched. Like Scannerdanner says, you have to have time in the field to be proficient. Thank you doing these videos. I always enjoy your lessons Mike.

4 channel both ecu's, perfect. Learn tons from your channel, and today it's easier and faster to communicate and learn than 1993 when I was just starting out on vehicles professionally. Thanks to all the professional instructors out there paying their dues and passing it on. Thank you!

I feel your pain , I once spent nearly 8 hours going through a wiring loom only to find a very thin wire which had broken and had the greenies. 5 mins of soldering then an hour of reassembly 😖😖😖😖😖😖. The owner had paid three other shops good money to fix it, but he only wanted to pay me for the soldering.....I was losing the will to live

That's how we learn. You found it and you fixed it. As long as there are small pins like that one, with very small currents and signals running through them, pin fitment will be a problem after many years and miles.

U0101: Top reason is almost always a loose connector on the TCM 99% of the time!!! This bulky connector sits vertically on the TCM thus loosening with time between the cable harness and the TCM. Inspect, clean and secure the connection is one of the best first steps ever.

Had exact same, identical problem many years ago, on same 07 mazda 3. My first dealing with can bus communication, ( like a lost child with my vantage 2500) replacing the tcm got the car out of the shop, but thanks to your video, I'm skeptical that it was maybe, just maybe a connection issue....thanks again for another education.

Check the connector before taking the harness apart, on the basis of looking for the easy things first. Plus, the connector is going to be 1000x as likely as the splice since it's a lot more mechanically complicated. If both sides of the connector have a pigtail you can often test continuity through the connector which helps too

I had one years ago on a 1982 Mitsubishi Lancer Turbo. This car was an ex Rally car and the owner complained that he could not get it to start. We rigged a bypass so he could get the fuel pump to work. At the weekend we later discovered that the fuel supply connector at the ECU had drifted back away from proper contact with the pin. Turns out he had been swapping ECUs just before it got its problems. Nowadays at my age I always use a bright light and magnifying glass to inspect the ECU plugs.

Thank you Mike. Have a blessed and safe week to you and your family. Thanks for the redkap shirt info. Got mine today. Nice shirts.

Incredibly helpful for the home diy, really great process of elimination.

@GoTech Mike, I've run into that kind of problem, with my own car, a 2004 Dodge Neon R/T, with a cam sensor issue. Kept getting the P0340 code, checked the wiring and replaced the sensor. Later figured out that the problem was the tabs inside the pins in the connector. The tabs had spread, causing an intermittent contact issue. It didn't help that the wiring harness was moving when the engine moved under acceleration. I simply pushed the tabs back in, fixed the issue for good, That was a few years ago. Have not had any cam sensor issues since. It is likely the same issue with this issue, and why the pin feels loose when the backprobe pin was inserted. Another issue that i've found is that sometimes the pin will not be inserted all the way into the connector so that it gets locked in, and that causes issues like this. When the backprobe pin was inserted, it pushed the pin in far enough to lock it in and make better contact with the other side.

Deja Vu. Our shop encountered this exact same problem on this exact same vehicle. All testing was initially done using the "back probing" method but every test showed no problem. To make matters worse, it was an intermittent problem. It would work great for a while then error out. I made the call that it must be an intermittent bad TCM, replaced the module, and the car drove fine ... for a while, then the issue returned (yes ... I ate the cost of a TCM). We switched to the "vampire tap" method for continued testing and that's when we found the problem. We were not able to find a used connector and had to replace the engine harness.

Excellent work. I always look for the mechanical failure in electronics first. They are more prone to fail that the electronics themselves.

I've experience a similar issue on Toyota Landcruiser GXR. It was the connector pin of the Transmission.

Great tips; you quickly narrowed down where the problem had to be, and you learned a lesson about checking the integrity of the actual connection instead of relying on back probing, which takes the actual problematic, low-socket-tension connection out of the tested circuit. If you had started by popping the white cover off of the sockets, you may have been able to spot the loose female connector by visual inspection before back probing that circuit and using new wires to go around the possible problem areas you had quickly identified. Thanks for making this video. I have a similar problem I am getting ready to dig into today, and the sharing of what you learned is extraordinarily helpful to me.

And it probably didn't need a TCM in the first place. Like I always say it's always something stupid. Most times we never get the whole story from the customer. Thanks for the video!

Nice find, Mike! I don't get many jobs like this, so on the rare occasion I do, I find myself fumbling like a rookie and wasting more time than I care to admit. 45 minutes ain't bad in my world, LOL - I bet I'd quadruple that! No matter how many vids I watch on this, I seem to forget everything as soon as the vehicle is in front of me, lol. It's like stage fright! I'll get it one of these days! My 10 year plan, HAHAHA! Great stuff as usual man. 👍🍻

Thank you Sr.for your time and communication

I deal with many 5 vdc connectors similar to that in late model domestic refrigeration and MANY times have found an invisible micro-corrosion has occurred. It can throw off a 2-5 kilo ohm sensor to alter a compartments temperature wherever the sensor is in control . Slightly feeezing or not cold enough, and in certain environments, unshielded and unprotected connections will cause a 12vdc fan motor or baffle actuator to stall. It is uncommon for those components to be the problem, but if you do not test anything and blindly replace the part, the action of disconnecting and reconnecting that will certainly make it look as if was correctly diagnosed since the connection was refreshed from the reassembly act. I usually dry fu-xk the connector a half dozen times and tweak both members of that union, and maybe use electricians tape to create a barrier, and that will buy it a few or more years. Almost never happens on the line voltage connectors. And it's usually the N side of the DC circuit .

Personally when dealing with a problem like this I try to have some one monitoring data communications on the scanner when I even have to move a wire just in case comms comes back. Have run into connection problems like this many times in the past 40 years. One of the reasons I warn customers about the perils of intermittent connections and the possibility it may temporally fix it's self and remain so for a long time.

Great advice fixed my problems IV been battling everything from pcm tcm wire harness I pulled every wire out didn't find no breaks in wres seen your video did probe test with a needle that was right size as pin found my bad female plugs thanks I've spent lots money time if only I seen this video first 😂

Having similar issues with my 2020 malibu rs....chevy can't even figure it out and its under warranty still. To the shop 3 times almost 2 months later still has not neen resolved. Great video !!

Had many issues with this problems,some cars are flood cars that were fixed by replacing modules and fuse boxes,which fixed the issue,but many yrs later we end up trying to figure out this issues,not knowing it was a flood car four yrs ago ,creating many pins to corrosion.

Thank you, it is great you saved me so much time.

Watching from philippines. Thank you very much for this technical idea sir. Big salute to you. Its very clear.

Haha, love it. It was probably someone jabbing it with a back probe in the first place that did it.

With this whole pandemic going on right now, there has been a lot of cases of male to female pin problems 😁 usually ends up in a no communication 😆

Amazing video it really helps to know what probably going to be done at the auto electricians in town with my ve commodore to find the problem I have with a pending U0100/P0700 fault codes

I currently have this U0101 code on my 2014 Chevy Malibu. When the TCM is down, the car is stuck in third gear (limp mode) and gear shift is not illuminated. When I drive 20-30 minutes in limp mode , the TCM does come back and stays as long as I keep driving. When I shut the engine off and wait about 10 minutes and turn engine back on, the TCM fails again, so it's an intermittent issue. Chevy dealership has no answers after I paid them 224 dollars in diagnostic fees. They wanted an additional $1300 to further diagnose it and obviously I declined that, so now I'm stuck with a TCM that goes in and out. Very frustrating. I have taken that TCM connector off and on so many times that I've lost count. Nothing is working.

Good reminder Mike. Tight is good. Thanks.

Great video. Use to hate piercing wires until I ran into same issue

These is a great check to the connector that could save $ 200 or more foa tcm reprogram or replacement.

I fixed a similar Mazda my buddy a mechanic replaced with new tcm, and still didn't work checked for tcm power signal with my autell no power did connector wiggle test power came on removed plug retighned terminal was fixed

Great video, and I am hopeful that it will help me fix my Rainier issues.

Great video and good lesson to learn, as always I appreciate what you do.

Good video and good tips to diagnostic thank you

Same thing happened when I was running parameter diagnostics on my TCM and T/C my Jeep was making a lot of loud noises from relays. Got better after a few restarts

Yes Thank you for the indepth quick video. Now to fix my $700+ dealership diagnose with already computer flash for the ecm. I didn't think to ask will that fix the problem for my u1000. But now u1000&u1001 are friends. How in the future to fix it....

Great tip Mike,I’m glad all is well! 👍

This was a text book lesson of the birds and the bees. Things got a little frisky there at the end with the connector.

What kind of program/software do u use that has the wiring diagrams on them?

Omg thanks so much I can start my diag with the connector… Michigan cars bro 😭

Thank you for sharing your knowledge.

Excelente información gracias.

I owned a shop from 90 to 2000 I wish we had the info back then that ur audience has available to them now

@gotech. My transmission is stuck in limp mode and responds slowly in reverse to 80% pedal pressure. only DTC U0101; U0402. It's TORQUE FLITE 8HP70 transmission. I can't believe my transmission has failed at 40934 mi.

I got it: how do you know that female connector is bad if you don't get lucky, the story of men's life, and also it was a good video!

Had a Cadillac cts abs com issue. Eventually found the blue slide in wire retainer in the connector was broken and allowing the wire to back out when installed. No room to properly check connector. Only found the problem when i disassembled the connector in desperation!

Always love pin fitment issues, they can drive you nuts. Most of the ones I get are intermittent to the point they happen once a year. Enough to make you want to start drinking..

I can’t even locate TCM on the car I’m working on (2011 Altima Hybrid) . Identifix illustration is different. Very frustrating. Most thing I hate about electrical is figuring out which wire is which.

Good day i am talking to from trinidad and tobago my problem is that my mazda 3 keep going into forth gear while driving for it to go back to drive i have to take it off the engine and put it back on again for it to drive nomal again

Great job ❤❤

You can fix very fast, Thank for this class.

Thank you for sharing your diagnostic process, sometimes the simplest thing is in front of us. Keep it simple ;-)

At least you double-checked your work before returning it to the customer. As the saying goes, "Measure twice, cut once." That's still better than tossing a TCM at it for nothing like the customer did in the first place.

This is an excellent video my guy, same exact thing happened on my 06

Thank you you sir. Have a Merry Christmas and a happy new year!

Very interesting on your work

where are you located I like how you go about in doing diagnosis on the vehicles I got a vehicle where nobody can find why is burning too much fuel I was wondering if you can tackle that job

Hey Mike so What was you recommendation for repair? To Replace the whole harness, Connector, or remove that one pin and repair it. If you do pin level repair can you please make a video on that

How do i know for sure if the TCM is bad and needs to be replaced? or there is no way to tell ?

Good teaching, and thanks for the video👍👍👍👍👍👍👍👍👍👍

Thank you for this great lesson. Apreciated

WOW, I will try that. Thank you.

Very educational!! Thank you!! 😊

Good video thanks! Any suggestion with lost power steering on subaru crosstreck?? Thank you so much

nice video, thanks! what program did you use to get the wiring diagram-I like the way you were able to clear everything out except what you really wanted to look at-made it very clear then!

U said u were working on a wisconsin vehicle. Are u located in wisconsin. I am looking for some one that can trouble shoot the electrical. If not can u recommend some one. I prefer not to be the guy that just starts replacing things. I already have 1500 into it. Mechanic said we just have to start replacing parts. Had 2 different places lookk at it. Any help would be appreciated.

Interesting,, will have to keep this in mind,,

Hey, Mike. I am not really familiar with the CAN Network. I was hoping one day that you would do a lecture on. My main issue is the can controller and the can transceiver. Is the can transceiver incorporated in the can controller? Should I expect a communication code with a bad transceiver? I am expecting the answer to be no, because they always tell you to disconnect modules to find the one(s) with the bad transceiver(s), but I may be wrong. Your answer would be greatly appreciated!

Where can I get a tcm that's programmed for my vin?

great info

I really need that scanning tool for Mazda please, from Zambia

I have u1001 code on 2014 Chevy impala trying to figure out if I gotta replace my wires or my whole tcm assembly

I was getting the u0101 code. sen the tcm off to get fixed installed it. now im getting transmission solenoid malfunction codes

Thanks brother thats good work i probably would had miss it

Hi, great video. Can you remove the pin and squeeze it lightly with a pliers to add tension or does the pin need to be replaced? Thanks

Hello Mike, always enjoyable to learn fro the master and always appreciate ur time more communication videos please would be great and would be even better if you can explain how the can buss work and is communication system universal with all manufacturer and car maker like K line L line can hi and can low would be greatly appreciated. cheeeeers

Good job

hello mike what's the version of launch , autel and snap on are you using ??

I wld love to c u implement today to yesteryear testing

Had a U101 no communication with and module which disabled the abs skid control that actually was set because the downstream O2 sensor kept setting the PO420 and you have no idea how long it took me to figure this out lol

Yeah the first thing I would have looked at is Communication pins from the transmission to ECM

Hey mike how r u brother? Keep up the good work 👍

Does a new TCU need to be 'programmed' or if I order one from Amazon do I just plug it in? Asking for a friend.

Great vid. Thanks for sharing.

I got a Mazda3 2.3 115k 2004. I accidentally did a parameter reset in the pats ic. Now dashboard doesn't display the transmission selection at all. No communication to the pcm I can't even communicate with it. How do I fix this? It started out as head gasket job, smoking out the tail pipe. The orginal pcm had water damage. Now I can't even this thing to crank nor start. I will pay for help. Please help me

Sir Good diagnose I have question if any of them control module defective how to diagnose

So if you could do it again what would you do differently?

great tip thank you

Good information

EXCELLENT JOB CLEAR INFO!

I have a similar issue with my mazda 3 2005 2.3. It jumps when goes into second gear when engine still cold mostly . Could this be the TCM as well or wiring or conector ?

Could a battery that puts out only 8 to 9 volts cause a U0101 code? My car starts off a little rough but it still runs just fine and has no problems when driving.

Great info as always Mike and always a pleasure even if I can't have your shirt, lol. Does the NGK email still work? Want to send you a little live data video for possible feed back. Everything seems wrong but no codes type thing.

Thanks for sharing

Does the TCM need to be reprogrammed if replaced? Purchased a used one and replaced mine but didn't know they had to be programmed

Well done!

Do you have a website to show exactly pictures what you did because I have sent my tcm back to many times (all Computer repair parts). I just got it back and it's still acking up