converter kicking in too soon, sensor related?

[candyman74]

took the truck by the tranny shop yesterday cause it would feel like the truck was at a loss of power and the engine was bogging down. they drove it with the scanned and it was showing that everything was operating fine except the torque converter is being told to lock up too soon. the tech told me a sensor on the engine was telling the computer to lock up the converter prematurely. so which sensor would do that? im not getting an engine soon light or anything and it takes off fine and idles fine. anyone in the st louis missouri area that can help me out?

[NEUMANNZZ]

The control module controls converter clutch lock-up,
upshifts and downshifts based on transmission temperature, system
voltage, throttle position, transmission oil pressure switches (5) and
transmission input (engine) and output (transmission) speed sensors.

what year truck and transmission?


check tps sensor for smooth linear response. clean maf sensor. could also be an issue with the vss sensor. does the speedometer work?

[candyman74]

its a 2001 tahoe with a 4l60e. ill check the tps and clean the mass air and see what that does.

[Pauly]

This is all PCm controlled and any errors would set a code.

My truck did the same thing with the stock tune. OD revving 900rpm at city speeds makes for no throttle response and very poor acceleration.
I doubt there is an issue. Sounds like your trans guy is reaching.
Try pulling teh selector down into 3rd or 2nd, or get a PCM tune that raises your TCC apply point.

peace
PAuly

[candyman74]

This is all PCm controlled and any errors would set a code.

My truck did the same thing with the stock tune. OD revving 900rpm at city speeds makes for no throttle response and very poor acceleration.
I doubt there is an issue. Sounds like your trans guy is reaching.
Try pulling teh selector down into 3rd or 2nd, or get a PCM tune that raises your TCC apply point.

peace
PAuly
if i start in first or third it takes off fine. if i start in second it boggs down. it has 141,500 miles on it and i have not changed the fluid or filter on it. im getting ready to trade it in if i cannot fix it.

[NEUMANNZZ]

putting it in second the transmission will start in second.(normal)

[candyman74]

putting it in second the transmission will start in second.(normal)

it started doing this not too long ago. i really dont want to waste money on a flush or changing the fluid with that many miles its a wonder its still working. but on the other hand i guess its cheaper to do those than a rebuild, which i want to get done too. decisions decisions.

[Pauly]

if i start in first or third it takes off fine. if i start in second it boggs down. it has 141,500 miles on it and i have not changed the fluid or filter on it. im getting ready to trade it in if i cannot fix it.
Wasnt talking about from a dead stop, I am talking driving around in 2nd or 3rd to keep you from locking up IN od.

sTARTING FROM A DEAD STOP IN 1 OR 3 OR 4 will have the trans in 1st gear. Starting in 2nd, is designed into the trans program to help to get moving in snow/ice.

peace
PAuly

[speedracer326]

When you look at a stock tune, the only parameters that dictate when the TCC engages are TPS and vehicle speed. The values are different in each gear as well. If your speedo works, that only leaves TPS. I'm with Pauly thinking he's just trying to give you an answer because he doesn't want to admit he doesn't know.

[candyman74]

When you look at a stock tune, the only parameters that dictate when the TCC engages are TPS and vehicle speed. The values are different in each gear as well. If your speedo works, that only leaves TPS. I'm with Pauly thinking he's just trying to give you an answer because he doesn't want to admit he doesn't know.

thanks ill check the tps then

[juanillox8]

hey candyman, did you ever got your problrm fixed? im having the same problem on my 00 tahoe.