I've got an issue that is stumping most everyone.

I joined the forum in hopes that someone can give me some insight to the issue that my beloved Tacoma is having recently.

Every time I make a left hand turn, with the blinker on (fast blink like the bulb needs to be changed), and with any amount of acceleration, the transmission will not upshift. This also happens when changing lanes to the left. As soon as I turn the blinker off, it shifts as normal.

If I do not use a blinker at all, it shifts appropriately.

I feel like it's an electrical or a computer issue because of the dependency of the blinker, but I don't really know enough to be sure.

The guy at the shop where I was getting my smog test done said that was a new one for him and that with 187k miles on it, it probably wasn't worth looking into it because the chip was in the trans and they would have to break it down to get at it just to see what the problem is. I called a dealership to see if they have ever heard of this, they haven't, and it would cost $100 just to get it in the bay.

Has anyone heard of such a situation?

 

Did you change your blinker blub, or any accessory bulbs to LED?

If I remember correctly, some older vehicles need the resistance in incandescent bulbs to for the voltage to remain consistent in the circuitry. We had some issues with a Peterbuilt on my ranch when we changed the accessory and blinker bulbs to LED, and the issue was resolved when we switched back to incandescent.

 

Last time I changed them was in 2015 and didn't have this issue until about a month ago.

 

I had a weird anomaly with one of my toyotas, When you turned the wipers on and headlights on the lights would decrease/flash/dim with movement of the wipers. Turn signals also affected the lights. Turned out to be a bad connection at the battery negative cable grounding. I cleaned off the ground and it worked great/no problems after that.

 

At the very least I'd see if a bulb fixed the turn signal (could be a relay??). That would eliminate that portion of what may be a larger fault. Gotta say it's an odd one to see tied together.

 

I have a buddy that had this Durango. It needed an exorcism more than a mechanic. His turn signals, radio, lights ect would come on randomly with or without the key in it. He also had to pull the starter relay to turn the engine off lol. It was the the TIPM causing all the problems.
Good luck.

 

did you change the LEDs in your shifter console as well? P_N_R_D

 

Changed what to what?

Like mentioned, I'd check all your grounds. And wiggle some wires.

 

Fix the 'fast blinker' issue first, and see what happens to the collateral nonsense that is going on.

 

Ill try this first and report back.

 

I didn't mess with anything prior to this issue. When I changed the bulb I just replaced a spent one with a new one. (this is probably frustrating for folks that know what they are talking about)

 

Time to change your blinker fluid... Kidding

Check body/frame grounds, Fix your fast blink like Bama said

 

As others have suggested weird behaviors like this are usually the result of a bad ground someplace. These can be a real pain to find. One that commonly corrodes or gets loose over time is attached to the frame just by the rear driver side wheel. That would be the return path for all the tail lights including the signal lights back there. If it is flaky that current will find some other path to get back to the battery and can freak out anything along the way.

Like everyone else is saying fix the fast blinker issue. That is easier to diagnose because you can do it with the truck stopped while you poke around! Hopefully fixing the blinker will result in finding the electrical or grounding issue that is also freaking out the AT.

Good luck!

 

And????????????

 

https://youtu.be/IkdmOVejUlI

 

Pull the bulb out of the fast blinking turn signal and see if it does it then. Just leave the bulb out completely

 

Sorry folks. Got distracted with the Grand Prix in town this past weekend and then life.

I pulled the bulb from the fast blinking light and replaced with a good one and it did not fix the fast blink or the shifting problem. It might have made it less drastic but that could have also been hope.

Ill give updates as I get them. So far, sounds like an electrical issue -- hopefully something easy like a loose ground wire -- but either way, I'll have to so some serious learning to identify the problem. Any tips on where to learn more about the electrical system?

 

Reminds me of my '82 Firebird. When I pressed the rear window wiper/washer button, the radio would switch to an AM static frequency. Then, as I accelerated, there was on overtone in the AM static frequency that raised in pitch as the engine RPMs increased. The whole cacauphony came through the stereo speakers.

 

there should be a ground from the firewall to the back of the engine block or intake manifold depending on motor. Another from the battery to the body, easy ones first.

 

And clean your battery terminals.