HELP me diagnose a 4L60 issue please
 

Just sold the tranny in my 01 SS to a gentleman on this site and after the install of it he is having issues.

After the install he drove it to work and back home no problem and then washed the car when he got home. Now as soon as he puts it in gear the car stalls.

If he jacks the rear end up and puts it in gear and lets the car idle it is fine but as soon as he hits the brakes the car will stall.

he is getting a P0740 tcc circuit malfunction code.....car has a stock stall converter BTW.

thanks in advance!!!!

Kevin

Theres a problem with the TCC circuit. Could be a pinched wire, could be a bad tcc solenoid, 740 is an electrical fault. Don't have him just replace parts, find the problem. Check the wiring harness right on top of the bellhousing, make sure he didn't pinch some wires in there during installation.

Might end up needing to ohm out the tcc wire from the trans connector to the computer. and check all the wiring in the trans pan for shorts to ground.

thanks!!!....anyone else???

Thanks for the reply its my car and I just got off work. Going to get the car and start checking things out. Will keep you posted on what i find or dont find.

So far the tranny does work in limp mode with tranny unplugged. Found no broken, pinched or anything else out of the ordinary. Which leads me to believe the lock up solenoid is stuch. Still the only code is P0740. Any other ideas out there. Thanks Shawn

If it was an internal transmission problem a stuck tcc solenoid will still be stuck with no power.

P0740 is an electrical code for the TCC circuit. P0742 would be a mechanical problem.

It could be anything in the circuit from the tcc solenoid coil to the PCM, and all the wiring in between.

The easiest test I can think of is to cut the tcc ground wire in the big plug, I guarantee it'll either unlock or the wire has a rub through to ground inside the pan. This will tell you if the wire has a ground fault on the harness side, or in the pan.

And even if that works it'll still throw the 740 code because of the break in the tcc solenoid wire.

Just got done pulling the pan still no pinched or bare wires. My repair manual doesnt have a diagram to show me which solenoid is for the lock up so if anyone has a link to one that would help.

Are you doing an M6 to A4 swap? if you are you have different problems.

The TCC wire on the big plug is light tan with a black stripe.
https://ls1tech.com/forums/attachmen...se-tan_blk.jpg
It goes to pin 42 on the red pcm connector.
https://ls1tech.com/forums/attachmen...lease-ccon.jpg
As far as I know the solenoid is powered with 12 volts and operates by the pcm grounding it.
https://ls1tech.com/forums/attachmen...please-sol.jpg

Its just a simple a4-a4 swap I drove 34 miles to and from work with no trouble then start it and this happens. I still have the old tranny laying on the floor beside the car. If i knew which solenoid it was i would just switch the because the old one worked it was missing 3-4 gears. Thanks Shawn

Also tranny came out of an 01 ss and I have it in a 99 TA. Wiring is still the same correct? I also noticed with the rear end off the ground it would stay running but if you tapped the gas the gas peddle pulse back out right away. Thanks Shawn

I think your gas peddle issue is traction control. You mean the gas peddle pushes your foot back?

The tcc solenoid is the bottom pic in my post above, heres another view of it.

The pwm solenoid needs to be removed to get the tcc solenoid out. The pwm solenoid is held in with a clip that sticks out of the slot in the valvebody.

If you swap out the tcc solenoid you need to cut and splice the wires. I'd cut the negative wire and ohm it to ground (the harness side) if it's grounded then the problem is not the solenoid.

Well it is done, it ended up being a bad lock up solenoid thanks for all the help. the only problem now is the tcs off light is on all the time, cant turn the tcs back on but i will figure that one out later. Thanks again Shawn

glad u got it figured out....sucks you only got to drive it 34 miles before you had to swap out a part lol