2014+ owners having issues with their truck?

[Tavio511]

Down shift for acceleration or under decel???

While deceleration from 35MPH to 30MPH and from 25mph to 20mph.

[Stex]

While deceleration from 35MPH to 30MPH and from 25mph to 20mph.

 

Not good. Have this on my 09. Tune to turn off AFM helped.

 

Drive in manual and see if it still does it. Let the TCM down shift in manual. do not use the manual control. Mine would not buck in manual.

[Tavio511]

 

Not good. Have this on my 09. Tune to turn off AFM helped.

 

Drive in manual and see if it still does it. Let the TCM down shift in manual. do not use the manual control. Mine would not buck in manual.

 

 

It does it on manual too!

[joshw1303]

It does it on manual too!

Look for updates, I had my ecu remapped and just other day they remapped my transmission for surging. My truck knock on wood, drives awesome now. Don't feel the surge in D mode, that I use to!

[Stex]

It does it on manual too!

 

Dang, not good. Have they discussed flashing the ecm tcm? New trans? Is it a hard buck or just a clunk of the drive?

[Stex]

Look for updates, I had my ecu remapped and just other day they remapped my transmission for surging. My truck knock on wood, drives awesome now. Don't feel the surge in D mode, that I use to!

 

Was there an ecm/tcm update for your truck? Or they just flashed to see if it would help?

[Tavio511]

 

Dang, not good. Have they discussed flashing the ecm tcm? New trans? Is it a hard buck or just a clunk of the drive?

Both.

[Tavio511]

Look for updates, I had my ecu remapped and just other day they remapped my transmission for surging. My truck knock on wood, drives awesome now. Don't feel the surge in D mode, that I use to!

I really appreciated the suggestions!

 

Look for updates, I had my ecu remapped and just other day they remapped my transmission for surging. My truck knock on wood, drives awesome now. Don't feel the surge in D mode, that I use to!

I really appreciated the suggestions!

[joshw1303]

 

Was there an ecm/tcm update for your truck? Or they just flashed to see if it would help?

Nope GM said there was a bulletin on file to update computer for transmission.

[Tavio511]

 

Was there an ecm/tcm update for your truck? Or they just flashed to see if it would help?

Just flashed. My dealership hasn't got a clue on what to do.

[Stex]

Nope GM said there was a bulletin on file to update computer for transmission.

 

Man, would sure like to find that bulletin. My dealer says no update yet???

[Daryl LBZ]

Just flashed. My dealership hasn't got a clue on what to do.

 

 

Replace the transmission maybe?

[NitroCherokee]

Man, would sure like to find that bulletin. My dealer says no update yet???

Ask and you shall receive

PI1029: Upshift Clunk, Firm Downshifts - (Aug 2, 2013)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Subject: Upshift Clunk, Firm Downshifts

 

 

Models: 2014 Chevrolet Silverado 1500 2014 GMC Sierra 1500 Equipped with 5.3L Engine (RPO L83) and 6L80 Automatic

Transmission (RPO MYC) Built Prior to July 3, 2013

 

 

 

Condition/Concern

 

 

Some customers may comment on upshifts that clunk when the driver lifts off

the accelerator pedal at the beginning of the shift or about firm downshifts at

lower engine speeds.

 

Recommendation/Instructions

 

 

 

A revised calibration has been developed to address this concern. Update the

engine control module (ECM) and the transmission control module (TCM) using the

Service Programming System (SPS) (select ECM/TCM Sequential Programming) with

the latest software available on TIS2WEB. Refer to the Service Programming

System (SPS) procedures in SI.

 

When using a Multiple Diagnostic Interface (MDI) for reprogramming, ensure

that it is updated with the latest software version.

 

During programming, the battery voltage must be maintained within the proper

range of 12-15 volts. Only use the approved Midtronics® PSC 550 Battery

Maintainer (SPS Programming Support Tool EL-49642) or equivalent during

programming.

[Stex]

Thanks, That should help Tavio511 and his '14. Checking with my service mgr. now to see if just applies to '14s. And if he can find the one GMMan1303 was talking about for his '11.

[joshw1303]

Thanks, That should help Tavio511 and his '14. Checking with my service mgr. now to see if just applies to '14s. And if he can find the one GMMan1303 was talking about for his '11.

When I get home, ill look at my dealer invoice and see what the mechanic wrote down.