my transmission keeps slipping when i have the boost set to 18-20 im currently at 15psi running at 248hp but my trq is at 260 but when im at 20psi my hp is 260 258trq.
why does my transmission keep slipping and going into limp mode, meaning its shuts off all power to the car and then im stuck there with a hard idle, with the dash reading Transmission service needed. PLEASE HELP

I was told by my tuner that the transmission has sensors on both sides of it, that when either one of them senses even the slightest slip, it shuts of the car

P.S I'm noticing it more when I hold the throttle half way in third gear, so it has part throttle and big boost, it seems like it doesn't like that, so it sends my car into limp mode. This normal?

 

Do you have the factory(OEM) tune saved on a computer somewhere? If so, I would flash your car back to stock and see if you still have the problem. If the problem continues to happen after doing that, then you need to take the car into the dealer for service. However, if the issue clears up after flashing back to the factory(OEM) tune, then you know that the problem has something to do with your custom dyno-tune.

 

sounds like someone has been flooring it at 2000 rpm in auto normal/sport modes too much.

 

well could the manual booster controller that i have be the problem? cause I didnt installed the boost pill cause the tuner wanted to use the controller. I have a 3in exhaust, intake, hks sqIII BOV, so im similar to you slee256 but your running a lil more, and dont seem to have any problems.

 

Sounds like the tuner forgot to raise the boost limits table. Most tuners max it out to 300+ to stop the computer going into limp during boost spikes.

 

well we did max out the turbo that was the goal of the whole tune, but he said once he got to 260 the tranny didn't Ike it, so i guess most ppl that are close to me or above in hp and especially Trq dont really dog on their cars when they reach this level.

 

is the correct way to test the boost PSI is to set it to a gear and floor it slowly , correct to see the max PSI? cause sometimes if i floor it hard it'll go over 20pis then settle somewhere between 18-20psi

 

Sounds like the DTC disables (airflow/torque limiters, etc) weren't used when you where tuned.

This will cause the high idle and the car going into limp mode.

Nothing wrong with the transmission itself being able to hold that power. Especially with the stock turbo.

 

Thanks Bryan, that's what I was trying say!

 

you're the expert here, while i'm still trying to learn, but wouldnt it be throwing maf codes (p123x or p124x) if it was something the dtc disable could fix? it seems like if the transmission service lights are coming up its more of a torque limits value issue? obviously with that torque level, on any dyno, a proper tune would not allow this to happen, and i'm not trying to be a jerk, just trying to understand how the ecu/tcu interpretations work

 

ya if it is truly throwing tranny codes, then im going with he has some kinda poor tune setup that isnt setting tables high enough and is causing the car to shut itself down as not to harm it cuz it is not in its normal limits