Hyundai TSB 21-50-003 Issued 23 July 2021 concerning 8 Speed automatics 2012-2015 Gens/Equus/Coupes

[deepevil]

After swap to new brake booster, transmission shocks disappeared

 

[Nfmosch3829]

After swap to new brake booster, transmission shocks disappeared

Why would that cause transmission shocks

 

[deepevil]

Why would that cause transmission shocks

The mystery about transmission hard shift is finally revealed (TSB for HARSH 2~3, 3~4 OR 4~5 UPSHIFT)

As the previous owner of a 2015 3.8 with the Hyundai Extended Warranty, I still experienced claim/honouring issues. Bought the car and Warranty extension out of Province, local Dealer repeatedly declined to acknowledge or respect it. Had issues with intermittent flickering headlights, Seat...

genesisowners.com

Here you will find the response

 

[Nfmosch3829]

The mystery about transmission hard shift is finally revealed (TSB for HARSH 2~3, 3~4 OR 4~5 UPSHIFT)

As the previous owner of a 2015 3.8 with the Hyundai Extended Warranty, I still experienced claim/honouring issues. Bought the car and Warranty extension out of Province, local Dealer repeatedly declined to acknowledge or respect it. Had issues with intermittent flickering headlights, Seat...

genesisowners.com

Here you will find the response

Ah didn't see that thanks buddy!

 

[Husam]

View attachment 38759

I'm interested to see this exact TSB if you managed to get a copy, please.

 

[JimmyJam]

View attachment 38759

Thanks @Roc! Finally purchased my first Genesis (6th Hyundai) a 2015, 3.8 with 141K. It has the Harsh or Delayed Shifting issue. Scheduling my appointment at Laird Noller Hyundai today. Will update thread after service. Appreciate all those who have come before me!
Nowe, to learn about the power trunk lift gate that unlocks and immediately shuts. It doesn't fully open.

 

[Sparty]

Thanks @Roc! Finally purchased my first Genesis (6th Hyundai) a 2015, 3.8 with 141K. It has the Harsh or Delayed Shifting issue. Scheduling my appointment at Laird Noller Hyundai today. Will update thread after service. Appreciate all those who have come before me!
Nowe, to learn about the power trunk lift gate that unlocks and immediately shuts. It doesn't fully open.

Any Luck?

 

[PETER.RHOADS.bills@GMAIL.]

Hello guys, new update with the problem of transmission.
Accidentally we found that on Genesis DH, there is a problem with Brake booster, the central membrane is broken in wet (medium) climate (i thinks its a time problem of anywhere).

The main idea that brake booster gain much more air than needed, and the valve isnt closed when needed, as a result, the ECM gain wrong data from the Torque sensor, and thats why we got transmission shocks.
In attachment you will see photos from two different genesis, with ODO km 70k km

Hello, and thanks for this important insight! Can this problem be identified by external inspection only, or must the brake booster be disassembled? Below is a picture of this brake booster for sale on Ebay, does this picture look like no rust problem?

 

[PETER.RHOADS.bills@GMAIL.]

Thanks @Roc! Finally purchased my first Genesis (6th Hyundai) a 2015, 3.8 with 141K. It has the Harsh or Delayed Shifting issue. Scheduling my appointment at Laird Noller Hyundai today. Will update thread after service. Appreciate all those who have come before me!
Nowe, to learn about the power trunk lift gate that unlocks and immediately shuts. It doesn't fully open.

How is your transmission saga going? I recently purchased a 2015 5.0 Genesis, love the car, but am seeing flaring and slightly harsh shifting, I am at 94k. I am going to replace solenoids and pan in a few weeks.

 

[deepevil]

Hello, and thanks for this important insight! Can this problem be identified by external inspection only, or must the brake booster be disassembled? Below is a picture of this brake booster for sale on Ebay, does this picture look like no rust problem?
View attachment 56703

Hello,
unfortunately no.

But those cases with brake booster, was the problem only from two of 20 cars.

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[0mar]

Anyone solved the problem?
I have same problem delayed shifting
And noticed there is delay respone in throttle