Need help with check engine p0740 code tcc circuit transmission???? - BMW Forum

97 bluebeamer · 08-09-2007, 11:47 PM

Hey guys,

I'm new to this site, I always used automotiveforums before. I have a 98 bmw 318i w/ 150k(auto). My check engine light came on, had the codes read and it is p0740 which is tcc(torque converter clutch) circuit malfunction. I got so many possibilities from people on what it could be like low fluid but that is not it because the level is fine, torque converter( I hope not b/c the gears seem to shift fine). Bad connectors or solenoid.

My question is that I want to know if anyone had this problem and what they did to fix it? Do u think I need a new solenoid and do u know if the whole tranny needs to be dropped to get to it or is it inside the pan which I can remove and replace the thing myself. Any help would be appreciated. I know it has to be electrical b/c I cleared the code and started the car without even putting it in drive and it came on. Somedays the light does not come on at all.

any help would be appreciated.

thx

mal

Starmavin · 08-10-2007, 10:57 PM

This is a performance code and comes up it's because the computer is not seeing a proper RPM drop when the tcc solenoid is commanded on because the tcc is not holding or engaging properly. Have the tcc solenoid replaced asap, they stick sometimes or the screen gets crap in it and it'll often fix it. If it gets ignored, it will kill the transmission. Drop the pan and check for glitter like gunk, metal or very "fuzzy" magnets. IF you find this start looking for another one or call a transmission shop. And if it comes out might as well rebuild it or replace it.

97 bluebeamer · 08-11-2007, 07:32 AM

thx for your help, I did my research on it and others r telling me it is a performance code and I will replace the solenoid today.

97 bluebeamer · 08-13-2007, 06:01 PM

I changed the solenoid, the fluid was dark brown but did not smell burned, I saw a little bit of glitter in the pan and on the solenoid but nothing major. My issue now is that the tranny seems to shift fine but the check engine light came up again, checked the code @ autozone and it is p0740 tcc circuit. It comes on as soon as I start the car, I dont even have to put it in D. What else can I be missing, I doubt it is the fluid level because if it was low there would be a delay in shifting into gears.

sportster 94 · 11-09-2009, 07:35 PM

I know it's been a while since you posted thiss; did you solve the problem? Can the solenoid be replaced with the tranny in the car? If so, where is it?