2017 - 2019 L5P T87A TCM Tuning | HP Tuners

Benefits:

• Increased transmission line pressure
• Revised shift schedule
• Improved shift timing
• Re-designed torque converter lock-up strategy
• Allows power transfer from the engine to the wheels more efficiently
• Allows transmission to handle the larger earlier torque curve that can be delivered by the L5P

Requirements:

• Requires a TCM Exchange
• 4 HPT credits
• MPVI Flash Device
• TCM Exchange Core refunds the core(s) must be received and inspected before refunded.  Cores with bent pins, missing pins or broken connector will not be accepted and refundable core fee(s) will be forfeited

 IMPORTANT: 

• All transmissions require a Windows based computer for the flashing of your transmission with your tuning option.
• Transmission tuning requires a TCM Exchange. 
• TCM tuning require an HP MPVI Device + Licensing for deployment.
• TCM Exchange core refunds the core(s) must be received and inspected before refunded.  Cores with bent pins, missing pins or broken connector will not be accepted and refundable core fee(s) will be forfeited. 

The factory TCM tuning from GM in the T87A leaves a lot to be desired when it comes to proper shift control and torque converter lockup (TCC –L/U). The programming, combined with a weak 7/8/9/10 clutch pack and overdrive drum arrangement leave this transmission vulnerable during loaded scerios and when power had been increased. Factory 10 speed trucks under full throttle from a stop shift in the order of 2/3/4/5th - TCC lockup/6th TCC lockup/7th TCC lockup/8th TCC lockup/9th TCC lockup/10th TCC lockup. This shift pattern arrangement makes for an uncomfortable pattern and shift control that users coming from a 6 speed Allisons do not perfer.

Additionally towing in the mountains or at grade GM has conventionally used a poor TCC and downshift scheduling. We find many users including ourselves have needed to place the truck in manual mode to be able to control engine breaking speeds and make the ride more enjoyable when loads are approaching max GVWR.

Furthermore the factory 10 speed operates with partial EEMC (partial lockup) of the TCC clutch nearly all the time. This is used by GM to make on and off throttle transitions more comfortable. We have found, after testing that we will be removing most of this partial EECM anytime the truck is under load to keep TCC slip down and efficiency up. There are no downsides to this. In fact most of the Transmission failures we have seen have been from torque converter failure.