Need help on transmission diagnosis
 

No noticeable symptoms until today. Drove to Harbor Freight and all was fine. Got back out and went to back out of my parking space and noticed the first strange effect. Car just stopped while going in reverse. Gave it a little gas and is started moving again. Shifted into "3" and the car moved but was sluggish and the RPMs were high. Felt a little like it was starting in second gear. Continued to happen at every stop on the way home. Also, I never felt the car upshift. I may have missed it but I got it up to a good speed and let off the throttle and nothing would change, gear-wise, that I could tell. Checked the fluid and it is a very light and clean pink and the level seems good. There are no noticeable leaks that I can see. Looks clean underneath.

Re: Need help on transmission diagnosis
 

Tony, FIRST check the line pressure and make sure this is done properly as per the official manual.

Re: Need help on transmission diagnosis
 

Thanks Trevor. I will need to bring it to my mechanic for that. Do you think a short drive in 2nd gear is OK or should I get it towed?

Re: Need help on transmission diagnosis
 

Update:

Car sat overnight and I took it for a quick drive this morning. Temp this morning was about 80F or 27C. When I observed the bad behavior yesterday, temp was about 95F or 35C.

Car ran fine! WTH?!?! No CEL so I don't think the tranny overheated yesterday. So I am guessing one of: sticky solenoid, bad electrical connection, bad TCU or bad TPS.

I don't know how the TPS could cause what I experienced but I do know it is going bad and needs to be replaced. The car was already scheduled for inspection Friday so I will have them check the line pressure as well.

Re: Need help on transmission diagnosis
 

Here is the long awaited TPS solution

https://speedyefi.com/product/tps-ad...VvpUpxx-LZfH8U

Re: Need help on transmission diagnosis
 

More info:

Still no CEL BUT P1702 code is stored in the ECU per my OBD2 code reader.

I read the transmission service manual and it could very well have been stuck in 3rd, not 2nd, yesterday. That would point to a solenoid 1 or 2 issue and it being put into limp mode. Or, it could be a TCU issue.

Anyone have an OBD2 TCU?

Re: Need help on transmission diagnosis
 

Wow! That's fantastic. I'm pretty sure mine is worn out. At exactly 80 kph the tranny hunts up and down between OD and drive, TC lock/unlock.. If I speed up or slow down it doesn't do it.

Re: Need help on transmission diagnosis
 

Are you talking about TC lock and unlock? That's what mine is doing and, yeah, I have been assuming a worn TPS. I have the one I got in the junkyard that I am hoping will last a while.

Re: Need help on transmission diagnosis
 

Yes exactly. It's been doing it for a very long time. I should try adjusting it.

Re: Need help on transmission diagnosis
 

Nah, just replace it. You know it is worn.

Re: Need help on transmission diagnosis
 

Mine has always had that feel circa 90 kph. Have always assumed it was the torque converter locking & unlocking.