TCC Solenoid? please help

[roush028]

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i own a 2000 Grand Prix GT- 3800 Series II. while im driving around if im going up a hill or step into the gas a little bit and try to get it to go a little faster or if im going up a hill and im trying to keep my speed up, the car shutters pretty bad and jerks almost like it doesnt want to shift. it will eventually shift down after a few seconds of doing this and go. but if you just step into it hard and make it kick dow it will and go just fine. but just easing on the gas to keep speed up a hill it likes to jerk and hestitate first. any ideas of what it could be? its pretty annoying. its almost as if it doesnt want to shift down when you need to pick up speed unless you stomp the gas really hard.

someone said it could be the throttle position sensor and i replaced it but got nothing. so it was a waste of 50 bucks!


also i dont know if this has anything to do with this problem but when im driving normal on flat highway everything is perfect except right when it shifts into overdrive when the rpms go down it will jump up about 200 rpm right after shifting into overdrive and then it goes back to normal. it justs jumps very quick?

any help would greatly be appreciated!

[GTP Dad]

This certainly sounds like the TCC is going bad. Unfortunately it is not a DIY job and will cost about $500 at a transmission shop to repair. Take the car to a tranny shop and have them check it with their scanner. They should be able to tell you the exact problem within a few minutes. Most shops will check it for free but some do charge a diagnostic fee. Of course it is better than replacing parts and finding out that was not the actual problem.

[BNaylor]

When it comes to suspected tranny issues it would help to post your current mileage. Also, when the last tranny service was performed such as ATF change and screen filter. Further, last basic tuneup such as plugs and wires.

Your are experiencing a common problem known as "fishbite" or "chuggle" which is the TCC locking and unlocking when it should not. In addition to a flaky torque convertor clutch (TCC) or TCC solenoid or valve body issue it can be caused by secondary ignition issues such as spark plugs, ignition wires or coil packs. When they get marginal can cause the "fishbite" and may not trigger a SES/CEL light since there is insufficient crank variation detected to store a misfire DTC.

Note that replacing the Throttle Position Sensor (TPS) per the GM TSB out very seldom if ever is the cause or cures the problem so that normally turns out to be a waste of money as is insufficient or improper diagnosis of the problem.

[troy1]

shifts into overdrive when the rpms go down it will jump up about 200 rpm right after shifting into overdrive and then it goes back to normal. it justs jumps very quick?

any help would greatly be appreciated!

Thats really common, my car does it and I've been in numerous others that do it too. Its bad slow MPH/light throttle PCM program. Get your PCS checked out before you jump on the TCC solenoid.

[roush028]

how do you scan that and what exectly is a PCS

[BNaylor]

The PCS is Pressure Control Solenoid. Located at the valve body and it controls the transmission line pressure via the PCM module. You need to use a scanner capable of detecting tranny codes or extended GM codes like P1XXX. Look for a P1811 DTC which does not trigger the SES/CEL light but stores in history for retrieval.

Also, you failed to post your mileage and reply to queries about last transmission service and tune up status. This would be helpful when looking for assistance.

[roush028]

ok so do you know where i could take it to have it scanned? and sorry about that...it has 145k miles on it. i really dont have a clue when the last tranny service was since i bought the carwith 132k on it. so im lost on that.

[GTP Dad]

Take the car to a transmission shop. AAMCO, Cottman or a local shop will be able to scan the transmission for you. Usually the larger companies will scan it for free. With 145K miles you can expect some issues. Don't flush the transmission but you can have a fluid exchange or at a minimum a fluid and filter change. This may help the problem but the scan will be the definitive indicator of what is wrong.