jkpiitch

Weird shifting issue that just "popped" up overnight .... hard/delayed upshifting and downshifting when the car/transmission is cold ... after about 15 mins of driving, it resolves and shifts normally.
ALSO associated: when cold, the "Sport Mode" shifting will not work, no digital gear counter, no ability to upshift or downshift ... NOTHING .... then around the same time the COLD shifting problem resolves, the "Sport Mode" begins to work.
Has anyone seen this or have any ideas ? Is there any thermal sensor or feedback loop to the transmission ECU that might explain this ?

Thanks for any help !

whitetiger5

how cold are you talking about?

jkpiitch

Interesting,.. 14F ... but my experience has been just chilly mornings .... maybe in the 40s or 30s .... But it has been predictable, and repeatable .... makes me wonder how it works, could I have a faulty sensor ?
The car is a 99, with the 4 spd .... 208K thousand miles ..... had the transmission rebuilt at approx 170K
Thanks for the reply.

Davius

Sounds like your oil might be more viscous than normal? Cold oil = Thicker oil. Thicker oil causes problems. I hope they used Honda ATF. 3x3 drain/fill would be my first move to know that the oil is good and then start to check for other faults .That's if you even want to chase it. Could just warm it up every time you drive it... Good Luck!

whitetiger5

Manual states that it's the transmission temp, so perhaps the ATF temperature sensor is on it's way out but hasn't given any fault codes just yet?

jkpiitch

I think so ....definitely seems like a sensor could do this .... it was fine one day then the next it was not. Its not especially cold here .... GA in the springtime ... rarely gets below freezing. It did briefly show the TCS light, so that's transmission or ABS right ? .... it only light up once.

bbsitum

https://acurazine.com/forums/second-...-while-991193/ Some solenoid is acting in cold weather.

jkpiitch

Thanks for the reply ... I'm going to try cleaning out the solenoids. I had this tranny (99 TL 4 spd) rebuilt two years ago, but I'm thinking maybe the shop did not do anything with the solenoids.

bbsitum

https://acurazine.com/forums/2g-tl-p...-again-929434/ . This guy put video about it.

Saudade

While you're in there I'd suggest you change your trans filter as well.

jkpiitch

Well it been a while since I posted about this .... if anyone is interested here is what I did and learned .... Since it was obviously a temperature thing (transmission behaved normally after warm-up) ... checked the ECT (engine coolant temp sensor) ..... found it broken... literally snapped. replaced it and xmsn shifting problem instantly solved. The ECT send temp signals to the ECM .... the ECM also controls the transmission .... the ECT signal into the ECM was probably way off at startup .... bad data (garbage in garbage out) thing. Also learned something else interesting about this sensor on Honda J series engines (probably others) The sensor screws into the engine coolant system at a point where air pockets tend to form if your system is not properly purged of air. In very hot conditions the ECT can be reading the temperature of basically superheated air(steam) inside the coolant manifold. if that happens then again its garbage in garbage out. I read many posts regarding hard restarts when the engine was hot having sat for a short time ... sometimes refered to as "vapor lock" .... Anyway we had that happen several times summer of 2021 & 2022 .... I purged all the air out of the coolant system and it has not happened again.

Hope this helps someone.

jkpiitch

PS .... this problem had NOTHING to do with solenoids ..... although I considered doing that job ... never did. tranny runs very smooth