Bypassing the torque converter???

[jakewaze]

Hi
My transmission stuffed up a while back and I ended up getting another one out of a wreck and had a mechanic install it. (No Garauntee unfortunatley).
The transmision is fine, but I noticed the other day (on the fwy) that the torque converter isn't engaging. This causes the engine light to come on and then everytime it shifts gears its very harsh/quick and doesn't feel like its good for the transmission. If I turn the car on and off its fine again until I go over 80km/h for more than a few seconds.

Is there anyway of bypassing the sensor for the torque converter or something to stop the computer picking up a fault??

[Brett_jjj]

What car is it in?

[jakewaze]

My bad
its a vr v6

[acarmody]

What do you mean 'the torque converter isn't engaging'? Do you mean it isn't locking up?

[jakewaze]

Well it drives fine but once im at 100ks it revs a bit over 2000rpm and the engine light comes on. So i dont think the torque converter is locking up

[Brett_jjj]

If its VR or onwards then Id be checking what type of transmission it was that was installed.(4HDD,5HDD,6HDD,7HDD).All these transmissions will all bolt straight up and fit no problem,but the trans electrical plug doesnt always fit 100%.Some plugs have 12 pins ,others have 13 pins,and if you dont have the right one,it can set error codes.If the electrical connector on the transmission matches the number of pins in the cars connector,then Id be checking for a bad connection somewhere in the auto transmission wiring and connectors between the trans and ECU .Also it might just be that you got a transmission thats got a problem with it.Id also try clearing any error codes logged in the ECU by disconnecting the battery terminal for a minute or two.You can check what error code is being set when the engine light comes on by reading the link at the bottom of the post.It only takes a minute, and is as easy as 1-2-3 to do.This test should confirm what you are saying about the torque converter lockup playing up.(it should give you a certain error code. Example. code 67 means transmission torque converter clutch ON-OFF solenoid control ciricit fault)
---Checking error codes VR/VS (Revised)---

[Jacko84]

+1 you know your stuff brett jjj

[The1]

it could just be the on/off solenoid for the convertor as above, the trigger points can be changed in the memcal, so if it turns out it's a bad convertorand you dont wanna fix it, it could be tuned out.

[jakewaze]

Wow, very detailed reply Brett, thanks.
I'll start with checking for error codes and work out what transmission I have. Just gotta find the time now lol

Cheers everyone.
I will post up the outcome

[hako]

it could just be the on/off solenoid for the convertor as above, the trigger points can be changed in the memcal, so if it turns out it's a bad convertorand you dont wanna fix it, it could be tuned out.

Or you could just cut the wire to the lockup solenoid.

[WAFFEN SS]

What would happen if you cut that wire? Will the lockup solernoid stay locked all the time or will it slip all the time and never lock?

[The1]

the pcm would command the solenoid to lockup but because the wire is cut the solenoid wont move and it wont lockup.

[WAFFEN SS]

wouldent that be a bad thing to do then?

[The1]

i personally wouldn't go cutting the wire cause i can tune it out

[jakewaze]

Sorry for the late reply guys, got a motorbike recently and havent put any time into the car.
Results from checking the computer for fault codes
26 - Mass Air Temp Sensor Unstable Voltage
46 - No Reference Signal While Cranking
47 - 18x Reference Signal Missing
68 - Transmission Component Slipping.

Im Not too sure of what transmision I have, but after I went back to ask the mechanic that installed it he said that the plug was different on the new transmission. He obviously didn't see it as important to tell me this when I originally picked the car up.

So any more ideas lol from the new information??

[Brett_jjj]

It sound like the box is a VS box which has an extra pin in the transmission electrical connector.The VR box has 12 pins in its electrical connector,the VS box has 13 pins in its connector.You will need to get a 4HDD box instead which are 12 pin..As for the error codes,clear them by removing the negative battery terminal for a minute or two,then check the error codes again to make sure they have cleared and its just showing a continuous code 12,then after driving it for half an hour or so,recheck for any error codes again.If any return,check the wiring and connectors to the faulty sensor,if the wiring and connectors are ok,then renew the sensor,they wear out just like any other part.Cheers.

[James39]

Would this help?
1870 Fix - 4L60E "TCC Mod" 95/6 -> 94 also fixes P1870 - Impala SS Forum

[hako]

I'm only guessing here, but I figure that Brett is correct that you have a VS box with the extra pin (remember Jake?) and this is preventing the TCC from engaging.....this then makes the trans oil heat up as the trans is still slipping...this sets the code 68 as the oil is hotter than it should be with the TCC locked. Do a Google for "disable TCC lockup 4l60E" and you'll find posts like: '93 Lock-up torque converter problem - Car Questions, Answers, and Discussion
They will suggest cutting the TCC wire but it seems this then sets another code, so then they cut the PCM (or PWM?) and this makes the changes softer....anyways, have a read of the search results - you'll probably get totally confused.
I also recall seeing something about wiring up that extra pin - somewhere on JC so maybe a search on this forum.