Possible Transmission Problems

[Bluefire16]

Hey guys, after my head build the trans decided it didnt want to shift gears. ( I no they are completely unrelated and i didnt touch the trans)

Well, after me trying to figure it out and getting frustrated its currently at a shop and they say its electrical and its the TCU. I have a new TCU coming that is good and in working condition.

They say the fluid is good and the trans is ok.

Im not totally confident that its the TCU (although I DO NO MINE IS BAD, but i have been running it for 2 years, bypassing it with my RoadSurge Box)

Well i have the new box coming, say it doesnt help, what to check next? I asked them to check the solenoids but i guess they didnt think it was the problem. What mechanically could it be? Something when i jacked the motor up a bit possibly?

 

[sniver]

Often grounds can cause major malfunctions. Start there if it doesn't work out for you.

 

[Bluefire16]

Thats the one other thing i was thinking. I moved 1 ground wire, and was thinking that maybe its not grounding fully now.

Its at the shop at the moment, so i think it could be the culprit but i wont no till i get it back.

 

[sniver]

Hopefully it's something that simple. Post up what you find, when you get around to it.

 

[the_mork]

What gear is it in?

Check if it is an electrical control problem by supplying power directly to the solenoids to shift them yourself (very similar to the roadsurge box but a lot more basic) just take some alligator clips, and two toggle switches so that you can supply power (solenoids are already grounded) to the two shift solenoids. This will tell you for sure if it is an electrical control problem, and if it is not then you need to pull and clean/rebuild the valve body.

yellow wire = shift B
orange wire = shift A

reverse is A off B on
neutral is A off B on
first is A in B off
second is A off B on
third is both off
fourth is Aon and B off


These instructions are paraphrased from the Translab tech help page.

 

[Bluefire16]

^^ The guys at the shop actually tried this ( i believe)

 

[the_mork]

Results? If that worked then yes there is an electrical control problem in which case I would suggest that your roadsurge box has gone bad.

 

[Bluefire16]

Well they checked everything and said its just the fried TCU.... but thats why i was also asking for other possible ideas.

Like i said a new TCU is coming. I think i might have a bad ground wire as well. So i will check in a day or two once the TCU arrives.

 

[the_mork]

I suspect the roadsurge box can operate without the tcu, but I think having one would be nice for when you just want to go on a road trip and it should get your car running again.

The ground issue could affect the roadsurge box/solenoids if the transmission isn't grounding well but IIRC if that is the case then I believe that your starter would also be having issues.

If for nothing else a tcu is nice for diagnostic purposes.

 

[sniver]

I know for a fact a shift box can operate w/o a tcu, I had one for a year or two w/ no tcu.

Sent from my Droid

 

[Bluefire16]

Hmm looks like i will be looking into my ground wire (its the only thing i i can think of) Simply because its a ground that looks like it comes off THE SAME WIRE LOOM that goes to the TRANS wires.

If not i hope to god its just the TCU... im really getting tired of this

 

[Bluefire16]

MORE PROBLEMS! So i got a NEW TCU. Put it in the car... still in limp mode. This was a perfectly good working condition TCU.

While i took it for a quick drive, the speedo went CRAZY. Well good i thought, if its a bad speedo it can put the car in limp mode. Bought a NEW VSS. Still in limp mode.

The shop that had it for 2 weeks, looked at all the wires, reconnected and traced them all down. Bascially everything electrical is done. (except for inside the trans electronics)

I do not no what else to check or try other than check that valve body.

 

[the_mork]

What gear is it in?

Check if it is an electrical control problem by supplying power directly to the solenoids to shift them yourself (very similar to the roadsurge box but a lot more basic) just take some alligator clips, and two toggle switches so that you can supply power (solenoids are already grounded) to the two shift solenoids. This will tell you for sure if it is an electrical control problem, and if it is not then you need to pull and clean/rebuild the valve body.

yellow wire = shift B
orange wire = shift A

reverse is A off B on
neutral is A off B on
first is A in B off
second is A off B on
third is both off
fourth is Aon and B off


These instructions are paraphrased from the Translab tech help page.

This test proves if it is the valve body or electrical. Don't bother pulling the VB if this makes it work fine. Have you pulled codes again? Either there isn't signal going to the solenoids and the issue is between the tcu and the solenoids as a signal issue, or the tcu will give codes unless it is bad.