1 - 2 Shift after cold start up

2015 Denali · June 3, 2015

Hey all, So I have a question if anyone has experienced this and if it is "normal" for GMs (been a Dodge guy for years and years).

After starting the truck and just beginning to drive, the truck hangs in between first gear for an unnatural amount of time and then hard shifts into second gear. After that, it shifts fine. It's just always worrisome because it feels like it does leave first gear, but it hangs between gears for about 1.5-2 seconds then goes to second super fast.

There are no clunks or other worrisome sounds associated with this behavior.

Is this normal for this 8 speed tranny perhaps? Or is it dealership visit worthy?

It's only got 1,100 miles so I am probably just being overly concerned about something that is nothing...so just tell me that too if that is it

Thanks!

CounterMeasure · June 3, 2015

Its "normal" from what I can tell. Many people on here have complained about the 1->2 laggy shift, myself include. Welcome to the wonderful world of the 8L90 transmission!

2015 Denali · June 3, 2015

Its "normal" from what I can tell. Many people on here have complained about the 1->2 laggy shift, myself include. Welcome to the wonderful world of the 8L90 transmission!

Thanks CM, appreciate it!

Rme2513 · June 3, 2015

Yeah it's normal mine also does it and when it's cold if you shift stright to drive mine will slip it's like it takes awhile to prime up fluid

fondupot · June 4, 2015

Yea. Mine does it too. Worse in colder temps.

Jordan18 · June 4, 2015

Mine does it as well. It seemed to be more pronounced after about 1000 miles were on the truck.

2015 Denali · June 4, 2015

Thanks everyone for telling me what is "normal". That feeling of the truck falling on it's face will just take getting used to.

Rme2513 · June 4, 2015

Thanks everyone for telling me what is "normal". That feeling of the truck falling on it's face will just take getting used to.

yeah I hate to say it's normal to because it should not be but I guess we should say it's normal for the 8 speed and yes it sucks that it's this way

Jordan18 · June 4, 2015

My truck goes in for Xpel rockerpanel and fender protection tomorrow, I asked about this update below and they said they would perform it. Apparently it's "30min TCM" update as the lady at the dealer said.

I'll see if this changes this at all.

#15389: Service Update for Inventory and Customer Vehicles - Torque Converter Clutch (TCC) Shudder - Expires with Base Warranty - (May 26, 2015)
Subject: 15389 – Service Update for Inventory and Customer Vehicles – Torque Converter Clutch (TCC) Shudder – Expires with Base Warranty

Models: 2015 Cadillac Escalade, Escalade ESV
2015 Chevrolet Silverado
2015 GMC Sierra, Yukon Denali, Yukon Denali XL
Equipped with 8L90 8-Speed Transmission and 6.2L V-8 (RPO M5U and L86)

--------------------------------------------------------------------------------

This service update includes vehicles in dealer inventory and customer vehicles that return to the dealership for any reason. This bulletin will expire at the end of the involved vehicle's New Vehicle Limited Warranty period.

Purpose
This bulletin provides a service procedure to reprogram the transmission control module (TCM) on certain 2015 model year Cadillac Escalade, Escalade ESV, Chevrolet Silverado, GMC Sierra, Yukon Denali and Yukon Denali XL vehicles equipped with an 8L90 8-Speed (M5U) transmission and 6.2L (L86) engine. These vehicles may have a condition in which transmission calibration allows a higher than target energy input to the torque converter clutch (TCC) under certain conditions. This may lead to faster than expected torque converter clutch material wear, and a shudder feeling when the TCC is applied.

scott19677 · June 4, 2015

My truck goes in for Xpel rockerpanel and fender protection tomorrow, I asked about this update below and they said they would perform it. Apparently it's "30min TCM" update as the lady at the dealer said.

I'll see if this changes this at all.

#15389: Service Update for Inventory and Customer Vehicles - Torque Converter Clutch (TCC) Shudder - Expires with Base Warranty - (May 26, 2015)

Subject: 15389 – Service Update for Inventory and Customer Vehicles – Torque Converter Clutch (TCC) Shudder – Expires with Base Warranty

Models: 2015 Cadillac Escalade, Escalade ESV

2015 Chevrolet Silverado

2015 GMC Sierra, Yukon Denali, Yukon Denali XL

Equipped with 8L90 8-Speed Transmission and 6.2L V-8 (RPO M5U and L86)

--------------------------------------------------------------------------------

This service update includes vehicles in dealer inventory and customer vehicles that return to the dealership for any reason. This bulletin will expire at the end of the involved vehicle's New Vehicle Limited Warranty period.

Purpose

This bulletin provides a service procedure to reprogram the transmission control module (TCM) on certain 2015 model year Cadillac Escalade, Escalade ESV, Chevrolet Silverado, GMC Sierra, Yukon Denali and Yukon Denali XL vehicles equipped with an 8L90 8-Speed (M5U) transmission and 6.2L (L86) engine. These vehicles may have a condition in which transmission calibration allows a higher than target energy input to the torque converter clutch (TCC) under certain conditions. This may lead to faster than expected torque converter clutch material wear, and a shudder feeling when the TCC is applied.

Is this bulletin for 8 speeds only? I have been having this problem on my 6 speed since new. here is a quote from last year.

Posted by scott19677 on 20 November 2014 - 10:33 PM

First gear = shudder, Second gear =shudder, Third gear= feels fine. I don't know if its the trans, or tq management but all three of my 2014s do this. I would like to hear from someone if this could be fixed with a tune. It just doesn't FEEL right.

Jordan18 · June 4, 2015

Is this bulletin for 8 speeds only? I have been having this problem on my 6 speed since new. here is a quote from last year.

Posted by scott19677 on 20 November 2014 - 10:33 PM

First gear = shudder, Second gear =shudder, Third gear= feels fine. I don't know if its the trans, or tq management but all three of my 2014s do this. I would like to hear from someone if this could be fixed with a tune. It just doesn't FEEL right.

Does state just 8 speeds with 6.2L in the bulletin but I don't see why there shouldn't have been one for 6 speeds if there were reported incidents. Or maybe a previous bulletin I have not seen before.

You could take this to a dealer and state you are having these exact symptoms in the bulletin and see what they say.

towerrigger · June 5, 2015

Just had this update done on my 15 AT with the 6.2. If anything it's worse than before. Mostly notice when gas is let off in 2nd gear and slowly get back into it. It will make a fairly hard thud. Back to the chasing it I guess.

2015 Denali · June 5, 2015

My truck goes in for Xpel rockerpanel and fender protection tomorrow, I asked about this update below and they said they would perform it. Apparently it's "30min TCM" update as the lady at the dealer said.

I'll see if this changes this at all.

#15389: Service Update for Inventory and Customer Vehicles - Torque Converter Clutch (TCC) Shudder - Expires with Base Warranty - (May 26, 2015)

Subject: 15389 – Service Update for Inventory and Customer Vehicles – Torque Converter Clutch (TCC) Shudder – Expires with Base Warranty

Models: 2015 Cadillac Escalade, Escalade ESV

2015 Chevrolet Silverado

2015 GMC Sierra, Yukon Denali, Yukon Denali XL

Equipped with 8L90 8-Speed Transmission and 6.2L V-8 (RPO M5U and L86)

--------------------------------------------------------------------------------

This service update includes vehicles in dealer inventory and customer vehicles that return to the dealership for any reason. This bulletin will expire at the end of the involved vehicle's New Vehicle Limited Warranty period.

Purpose

This bulletin provides a service procedure to reprogram the transmission control module (TCM) on certain 2015 model year Cadillac Escalade, Escalade ESV, Chevrolet Silverado, GMC Sierra, Yukon Denali and Yukon Denali XL vehicles equipped with an 8L90 8-Speed (M5U) transmission and 6.2L (L86) engine. These vehicles may have a condition in which transmission calibration allows a higher than target energy input to the torque converter clutch (TCC) under certain conditions. This may lead to faster than expected torque converter clutch material wear, and a shudder feeling when the TCC is applied.

Let me/us knows how it drives afterwards!

CounterMeasure · June 5, 2015

Just had this update done on my 15 AT with the 6.2. If anything it's worse than before. Mostly notice when gas is let off in 2nd gear and slowly get back into it. It will make a fairly hard thud. Back to the chasing it I guess.

When I first picked up my truck, the shifting was fine until I started it cold. I suspected the update required a complete relearn, and I've now confirmed that is indeed the case. My transmission shifting was horrible after having the update done. It has since improved to "still sucks". Not quite a good as before in my opinion. In short, give it some miles and some of your gas money to let GM's software re-figure out what to do.

What I noticed more than ever after this update is the ECM adjusting RPMs for shifts contrary to what I want. If I hold steady pedal pressure from a stop and watch the tach, the RPMs are all over the place compared to what my foot is telling the vehicle to do. The band through first gear to get to the shift is a curve in accelartion until it does its very laggy shift into 2nd.

There's a huge difference in the engine dropping RPMs to allow the shift and then coming back so it doesn't bang into gear, and *adding* RPMs and thus acceleration to do the shift like it does. I don't like that it does the latter at all. The ECM deciding "I know what you are saying with the pedal, but no, I am going to ignore that and accelerate more so we can handle this large gear difference for the shift" is not cool.

towerrigger · June 5, 2015

When I first picked up my truck, the shifting was fine until I started it cold. I suspected the update required a complete relearn, and I've now confirmed that is indeed the case. My transmission shifting was horrible after having the update done. It has since improved to "still sucks". Not quite a good as before in my opinion. In short, give it some miles and some of your gas money to let GM's software re-figure out what to do.

What I noticed more than ever after this update is the ECM adjusting RPMs for shifts contrary to what I want. If I hold steady pedal pressure from a stop and watch the tach, the RPMs are all over the place compared to what my foot is telling the vehicle to do. The band through first gear to get to the shift is a curve in accelartion until it does its very laggy shift into 2nd.

There's a huge difference in the engine dropping RPMs to allow the shift and then coming back so it doesn't bang into gear, and *adding* RPMs and thus acceleration to do the shift like it does. I don't like that it does the latter at all. The ECM deciding "I know what you are saying with the pedal, but no, I am going to ignore that and accelerate more so we can handle this large gear difference for the shift" is not cool.

This is exactly what I have been experiencing as well. Hopefully it does improve with some miles. Hope to see GM come out with another update.