i have a 97 cav convertable automatic 2.4L. So whenever im coming to a real slow stop and or drifting slowly as well as making a sharp turn at low speed my car just shuts off. (starts right back up afterwards though) took it to a shop they said it was my egr. got that fixed and well a day later same problem only now its worse. took it back, they told me its a sensor in my transmission that doesnt know what gear to put the car in so to protect itself it shuts the car off. He said its cheaper to replace the tranny than to fix the sensor b/c its in the transmission and you have to take it all apart to get to it. What sensor is he talking about b/c i cant find anything like it in the chilten maneuel, especially one that needs the tranny to be droped and taken apart to get to it. (the shoped claim that there book said its a 22 hour fix). could the tcc siloniod be doing this?

If anyone could help diagnose my problem i would be greatly appreciate it.

dark nights wrote:i have a 97 cav convertable automatic 2.4L. So whenever im coming to a real slow stop and or drifting slowly as well as making a sharp turn at low speed my car just shuts off. (starts right back up afterwards though) took it to a shop they said it was my egr. got that fixed and well a day later same problem only now its worse. took it back, they told me its a sensor in my transmission that doesnt know what gear to put the car in so to protect itself it shuts the car off. He said its cheaper to replace the tranny than to fix the sensor b/c its in the transmission and you have to take it all apart to get to it. What sensor is he talking about b/c i cant find anything like it in the chilten maneuel, especially one that needs the tranny to be droped and taken apart to get to it. (the shoped claim that there book said its a 22 hour fix). could the tcc siloniod be doing this?

If anyone could help diagnose my problem i would be greatly appreciate it.

First off the shop is lying to, simply put. There is no sensor "in" a transmission, I've rebuilt tons of them, and there arent sensors in them, there are clutch packs/bands etc. The car isnt going to shut itself off to protect itself either. Is this shop a chain store or what, whatever the case I wouldnt go back there.

An EGR that isnt closing would cause a stall but at idle, since the EGR is open during off idle crusing, it is off during idle and accleration and deceleration.

The TCC solenoid, applies the torque convertor clutch to achieve full lockup of the torque convertor, if your TCC was applied all the time, your vehicle would stall instantly as soon as it was in park due to the load it puts on the engine, that isnt your problem.

Lots of things can cause your problem though, do you have access to a scan tool to look at any live data?

Check engine light on?

Do you have a fuel pressure gauge?



- 2004 Cavalier - 124k, owned since new

check engine light is on.
dont have any gauges. or scan tools.
since it starts back up everytime though would we still be leaning towards a sensor?

Do you know the check engine light code, that would possibly point you in the right direction.



- 2004 Cavalier - 124k, owned since new

no sorry. what sensor though would the be talking about or would this not be a sensor issue?

go to autozone or somewhere like it, they will most likely be able to read the code that is causing the CEL to be on, and tell you what it means. to me it soulds like it could be the idle air control valve. if its sticking, or not working properly it could cause the car to stall out when the engine is decellerating to an idle. the IAC sits on the front of the throttle body all the way on the left side. it has 2 Torx bolts holding it on either a t-25 or t-27 take it off and look for excessive carbon buildup on the valve, or in the hole on the TB and go from there. and your mechanic is either a @!#$ moron or hes trying to rip you off.

could this be a crank sensor going bad?

TCC solenoid...

as stated above... yes, if it was open all the time, your call would stall instantly or not start at all.... however, it only needs to stick open while decelerating to the stop to stall the car out.. once it finally shuts/disengages, your car will start back up like nothing happened.. also if it were completely stuck open, you'd be throwing DTCs.. so it is a very likely cause of both our problems (currently having the EXACT same issue and its narrowed down to the TCC)...

im trying to find out whats involved in replacement but the tranny forum seems dead,, lol

thanks. let me know what you find out please. how much is a new tcc?

paul bateman wrote:TCC solenoid...

as stated above... yes, if it was open all the time, your call would stall instantly or not start at all.... however, it only needs to stick open while decelerating to the stop to stall the car out.. once it finally shuts/disengages, your car will start back up like nothing happened.. also if it were completely stuck open, you'd be throwing DTCs.. so it is a very likely cause of both our problems (currently having the EXACT same issue and its narrowed down to the TCC)...

im trying to find out whats involved in replacement but the tranny forum seems dead,, lol

bingo, just unplug it. If it stops then you know for sure thats what was causing it..

can u drive it around unplugged?

from what i understand myself (as i said, im looking for more info in the tranny forum), you can drive around with it unplugged as some have claimed to be doing just that rather then replace it... you'll just burn more gas.. think of it as being like 500-750rpm higher at the same speed when cruising...

now as for replacing it... you do have to do some digging into the tranny... apparently on some models, its a simple job... on others, the cars design makes it impossible to do while still attached to the car...

dont quote me on any of this.. passing along what i have heard/read so far... I myself am looking for clarification on this as well... same issue on my 99 z24... tho its not constantly happening to me, my commute is about 1km to work and its all 50km/h and under.. only happens when im coming off the highway (or if i was having fun on the backroads..lol) as i dont think the tcc engages until 45mph/80ish km/h..

from what i understand myself (as i said, im looking for more info in the tranny forum), you can drive around with it unplugged as some have claimed to be doing just that rather then replace it... you'll just burn more gas.. think of it as being like 500-750rpm higher at the same speed when cruising...

now as for replacing it... you do have to do some digging into the tranny... apparently on some models, its a simple job... on others, the cars design makes it impossible to do while still attached to the car...

dont quote me on any of this.. passing along what i have heard/read so far... I myself am looking for clarification on this as well... same issue on my 99 z24... tho its not constantly happening to me, my commute is about 1km to work and its all 50km/h and under.. only happens when im coming off the highway (or if i was having fun on the backroads..lol) as i dont think the tcc engages until 45mph/80ish km/h..

and the tcc is available from partsource for $70.. tho im sure i can find it cheaper... but its the labor that will hurt on this job...

First of all, What transmission do you have? 3spd or 4spd? These two are vastly different in tCC operation.

If you have a 4 speed 4t40E try driving it around in 3 instead of Drive...this is 1,2,3 manual operation w/o TCC. If its a TCC issue you should not have an issue. Personally its a rediculous idea to go and unplug things inside the valve body or chopping up wires to disable it when you can do it

If its a three speed you should be able to drop it in manual 2 and do the same.



Buildin' n' Boostin for 08' - Alex Richards

i would think by his info hes got the 4t40e like i do... and i agree, i didnt like that whole idea of unplugging it or cutting the wire itself.. I wasnt aware 3 didnt use the TCC, thats something i will try out but i always thought it would engage in any gear once maintaining speed for awhile. isnt that its entire purpose?? i had only just read about it not engaging until 45mph.. i hate the internet.. hahaha

yea i have the auto 2.4l 4t40e. it doesnt shut off every single time but a few times a day make it annoying. and when going sharply around turns it shuts off and thats dangerous, but im kinda broke so im trying to figure out the problem so i dont get raped at a shop;

I am having the exact same issues as the original poster is right now, with my 1997 Pontiac Sunfire 2.4 4T40E convertible. I would like to know how to unplug the tcc solenoid for testing purposes. On my 95 2.2 Sunfire 3-speed automatic, which also exhibited the same symptoms, I just unplugged the harness going into the front of the transmission, and the stalling, etc. instantly went away -- therefore, I knew that the tcc solenoid was the problem. I could try manually shifting the transmission as Alex Richards suggested, but if the harness that goes into the front of the 4T40E transmission is for the tcc solenoid also, I could simply unplug it and test the vehicle that way as well. If anybody has any further information on this topic, please chime in! This issue is a very big problem right now.


I can't type in cursive!

Here's how to replace it: http://www.domesticcrew.com/tony/TCCreplacement.pdf

I think you'd have to cut wires in the harness to disconnect JUST the TCC... as the transmission only has one big plug going into it, if I recall correctly. Been awhile since I had an automatic J-body, sorry.

i could tell you which wire it is coming out of the main harness... but thats not a good idea.. lol..

I havent actually gotten down in the snow to take a peak at it to see if it has a connector outside the tranny.. the haynes manual is useless for anything transmission related as they just say you cant do it so there not gonna tell you how.. nice.. lol

drove into work this morning in 3.. the car definitely drives better but to be honest, my car would only ever stall after cruising at 80-100km/h or hard driving.. maybe i'll take er out at lunch and see if i can get her to stall in 3... could always in drive, accel to 100-120 and lift on the gas.. rpms will drop normally til 1000 or so where it should stay.. then they very quietly fall off and the car stalls... i dont even notice it happen, it does it without any shake or anything... almost like i turned if off...

actually... you say your car shuts off when making a sharp turn?? i recall someone on here having that problem and it was a wiring issue i believe.. something with the wheel turning pulling on a harness or something along those lines... might be worth a search.. it was recently..

im guessing its the plug in play where you would connect the autotrans interceptor if you would have one? anyone know which wires for sure to cut? ill do it cuz im pretty sure thats the problem from what im hearing from other cav owners. cutting the wires you only really lose a few probably unnoticable miles to the gallon in gas mileage

also ive heard you only have to get the car up to 45mph to get the tcc to lock up or w.e. then when you slow down sometimes it doesnt disengage and you car shuts off.

i have the same problem you have, but yea when i slow down and if its a sharp turn the combination turns the car off almost everytime unless i give it a lil gas through the turn or pop it in nuetral of course.

i wouldnt recommend cutting the wire...

but its not safety related so its up to you i guess... its the brown wire in the main harness... there is only the one wire for TCC operation.. its clearly marked in the haynes manual diagram which i would strongly recommend looking at before cutting anything!! lol.. just to be safe..

one guy cut the wire and ran it to a single pole switch in the cab and was manually turning it on when he hit the highway and off when exiting... seemed like an idea.... although i think that would only work if it was the ecu signal that was bad... manually cutting power to it will have the same effect as the ecu cutting power to it... nothing... its stuck! lol

Quote:

then when you slow down sometimes it doesnt disengage and you car shuts off.

exactly.... at least exactly how i see it... haha

well i was talking to a few people 1 a mechanic who pulled the tcc plug out. on the 2.2l its a stand alone plug. it fixed the problem. im told since the 2.4 put all the wires in one plug you would have to cut the wire to have the same affect to fix the problem. i have a chilten manuel ill have to look it up in there to be sure. i figured wires can always be twisted back together. i have friends that are electricians. still debating it though.

yeah.. its just never a good idea to cut anything in your main harness (do you know what GM wants for a new one??? eek)
but yeah... you could always just re-attached the wires, its not really rocket science... lol, Im still hesitant to do it too though... If i pay attention to what im doing. i can keep my car from stalling so it isnt urgent in my case...

Thanks to John and others for the input. Has anybody come up with a solution yet?


I can't type in cursive!