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Discussion Starter #1
Alright guys need some help here, most problems I can tinker with and figure out but transmissions are particular mystery..lol.
Well my daughters 98 Wolfsburg edition 2.0 has suddenly thrown two codes and from what im guessing has gone into limp mode.
PO 730 = gear incorrect ratio.
PO 740= torque converter clutch circuit malfunction.
Now the car is hard to shift out of 2 to 3rd. Rpms gotta be around 5500 to shift. Feels like its trying to stop itself.
My question is as a complete transmission noob,, where would you start looking? Is there a relay that could be checked, or may be the tcm?maybe a wire , or harness?
Could one code caused the other? Moneys tight and its my daughters car whi needs it for college in less than a month, so I really could use some help not chasing my tail and wasting money I dont have. Any tranny ninjas out there?
 

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Hi, I am not transmission specialist, but my first port of call would be a gearbox oil flush and then new oil and filter. I think that most of these problems are related with the hydraulic circuit which would tend to get gunk and possible metallic particles from normal wear that would tend to wear out solenoid actuators and block passages reducing oil pressure and giving out all sorts of symptoms. It should be easy enough, you don't loose anything even if that is not the problem and should improve the overall transmission feel.
 

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Discussion Starter #4
Update, I have flushed the fluids twice, changed the filter, filled it... nothing.
I Pulled the pan again and tested solenoids for resistance. Look good, now I know that the two (ecc & tcc) can still be bad, but im wondering if I shouldnt be looking at the n88 solenoid as it controls the 1_2 &3_4 shifts. Or should I pull all of them. Still unclear if its the harness external or internal. Cant seen to find a good write up.
Im going to swap the n88 & the n92 and see if it shifts then. Just cant afford to replace all, for all that, I can probably poke around enough to find a used one.

Any ideas guys?
 

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I am just looking at the original error codes and if you have incorrect gear ratio, could it be an issue with a speed sensor in the engine vs gearbox inducing the ECU in error and not shifting?
 

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Well that didnt work, will have to drpp the pan again to switch them back. As it had no effect.will look into the speed sensor. As well as keep searching for the tcu pin number to solenoid harness wires.
 

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Discussion Starter #7
Ok so I went out and reset the (tcu?) By turning the key,gas, method and noticed a change when in D it feels like its stuck in third, but today( wasnt doing this the other day) when I manually downshift while driving it clunked into 3rd? And from a dead stop it feels like it goes from 1_2_3 and then I lose D altogether.the gear select indicator comes on when I manually shift, goes off when limping in D.....
So thats something.......
went to AZ and read codes again this time came up with 3, the same two as above and a new one,, po753 "shift solenoid A electrical" so im assuming that means the harness is reading the change in solenoids. Gotta find out which one is " A" and replace that one I guess......
This sucks....
 

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You should take care that the error code is not due to the swapping you did. Is it possible the circuit was energised when the valve was off? if so, that would have stored a code but it would not help you. I suggest you reset the codes, drive the car again after doing the DCU reset and then read them again. If it comes up again, at least you know it was not from the swap. Best of luck!
 
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