Code P0740

[BLZNHOT97]

Hello,

I'm new on this board :) and was wondering if anyone can help me out. I have a 97 Chevy Blazer LT 4X4 and I have this code P0740. This is the Torque Converter Clutch Circuit. What I need to know: is this internal or external? How long would a job like this take roughly? Sorry if I'm not explaining it right but I'm a girl that needs help since no one in my area (Toronto, Ont) can figure this out. :confused: If anyone has any info can you email me at kicker_livin_loud79@hotmail.com (kicker_livin_loud79@hotmail.com).

Thanks alot,

Jp :o

[chevybrat]

Hey! Welcome to the site! I'm also female, not many of those around on this site seems like. I'm Heather by the way, from Seattle. I have a 2001 Chevy s10 ZR2. I unfortunately can't help you with your problem but there are a ton of informed helpful people here who i'm sure can offer assistance in guiding you in the right direction. :-]

[Mikz86TA]

Welcome to The PLANET!!! The code is the TCC (torque converter clutch )circuit. It should throw above 50mph when the TCC doesnt engage. This isnt a big deal but will cause gas milage drop. The TCC it designed to 'lock' the motors input directly to the trans to not allow the normal slippage that the torque converter posesses naturally. RPMs lower when its engaged and it saves gas milage. Could be the wiring is loose or a bad TCC solenoid. Inside the tranny. It sounds expensive but its not. Dropping the trans pan (like you do when servicing the tranny and replacing the filter) gives you access to it. GM dealer or a tranny shop should be able to narrow it down. IMO, I would have it diagnosed, have a full service done with filter change and have the solenoid replaced all at one time. If that ends up being the issue for sure. Hope this is helpful =)

[BLZNHOT97]

Well, I brought my truck to Mr. Transmission and I have serval codes! One is a htr o2 sensor (bank 1 sensor 2), the other 2 are (i think) solonoid 1-electrical, and solonoid 2-electrical and shift timing (im not sure exactly the whole name) but the guy at Mr. T says he doesnt understand it possiblely cant be all the solonoids but if it is saying "electrical" it might be electrical. he says it might be my alarm or stereo set-up. If anyone has any input on this (i know i might not be explaining this right... sorry) please email me at kicker_livin_loud79@hotmail.com

thanks everyone,

[87wildside]

Sounds like a ground problem for the solenoids. Could also be the electrical connector by the transmission. BTW welcome to The Planet.

[BLZNHOT97]

Thank you for the welcoming!:)

[Mikz86TA]

BS!!! Its not the Alarm OR Stereo. Just because he cant narrow it down is no excuse to blame something un-realated. If 2 solenoids are showing up defective its most likely a bad ground, shortened wire or the solenoids are chained together in series.

[BLZNHOT97]

So this is an electrical problem? Sorry for all the questions, but I'm so super pissed that these asses are making me run around with a truck that doesnt run properly cuz they don't know what's going on!!! I'm just tryin to understand this. My guy friends told me the same thing that it is not the stereo or alarm! It might be the o2 sensor. Do you think I should try bringing it to an Electrical shop?

[87wildside]

The first code is for an O2 so yeah, that is probably bad. Are there any drivability problems? If so give an idea to what it's doing.


I think Advanced Auto parts will check the codes free for you. Go there have them pull the codes and clear them if they will. This is just to see if the codes come back and if these guys were giving you BS. It' an ongoing joke here but are the names of the guys at the shop Bubba or Junior?

[jswag5]

i need to change out the harness and electrical system in my blazer too, i had it out when i rebuilt, but negleccted the electrical, its not expensive, just a little bit of a PITA

BTW http://www.transmissionpartsusa.com/4L60E_transmission_parts_s/ (http://www.transmissionpartsusa.com/4L60E_transmission_parts_s/642.htm)has the whole harness and switch setup like 40 bucks