Transmission started going crazy! L99 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Myke783 · 10-11-2016, 06:59 PM

So just flew back in town, from Business.
Excited bc it's my birthday, but more so coming home to my beautiful Camaro lol.
Went for a drive, and within 5 miles the car decided to have a mind of its own. I was cruising 65ish in Sport mode. When my transmission just decided to jump to like 3rd, then to 4th, and continued in a unpredictable pattern. Then it locked up on me, as did the rear tires, then it engaged back into gear.
I immediately pulled to the shoulder. To figure out what the hell just happened. I noticed that the car will no longer go into reverse, in neutral it tries to coast at low speeds.
I was able to get it home in manual mode. But if I tried to go into 5th or 6th, the rpm's would start going crazy again.

I'll be taking it to the dealership within the next few days.
You guys have any ideas or guesses as to what the issues may be?
I've felt transmissions slip, and torque converters shudder. But the way this was, it seemed like possible computer ecm/tcm issues? And possible transmission issues now?

hunter1660 · 10-11-2016, 07:09 PM

Did you buy the car new? Is it tuned? It sounds like your on the right track with your diagnosis

Cyber10 · 10-11-2016, 09:34 PM

When my transmission died it did almost exactly the same as your except I was doing about 40 up a ramp to get onto the interstate. My car shifted up and down a few times before I heard a thud and I had no more power below 4 gear, fortunately I made it over the ramp and got up into 6th and didn't hit traffic on my way to work and was able to get it to a shop later that day.

I have no clue what exactly went wrong with mine as I chose not to rebuild it and bought a new one instead, tuner agreed that whatever the problem was it was definitely the transmission(as if it was even a question after seeing them pulling shards of metal out of my converter lol). Seems like the only difference between us is my low gears went while you're having problems with higher gears. Let us know what the dealer ends up saying, I'm genuinely curious as to what it is/what mine could have been.

chuckie669 · 10-11-2016, 10:40 PM

Eek... that sucks. How many miles do you have on your 2010 if i may ask?

CamaroFred · 10-12-2016, 12:02 AM

Drop the pan and change the fluid and filter. You might get a few more months out of it.

Myke783 · 10-12-2016, 12:12 AM

I bought her new. I had a dyno tune done years ago when I did LT Headers, etc. But have tuned her with my Diablo sport trinity doing custom ecm/tcm tunes. But never adjusted the tcm tune, other than disabling torque management.
However, my battery has been flaking out here and there. It did it, when I tuned it a few months back. But I re-tuned the car to make sure it didn't get corrupted when the battery died. Drove perfectly fine, and I logged it, everything seemed proper. So idk, really curious to see what the dealership says.

Myke783 · 10-12-2016, 12:16 AM

I just hit 85k miles.
I changed my trans filter, changed the gasket, and put new fluid in it back in April.

CamaroFred · 10-12-2016, 12:16 AM

Quote:

Originally Posted by Myke783

I bought her new. I had a dyno tune done years ago when I did LT Headers, etc. But have tuned her with my Diablo sport trinity doing custom ecm/tcm tunes. But never adjusted the tcm tune, other than disabling torque management.
However, my battery has been flaking out here and there. It did it, when I tuned it a few months back. But I re-tuned the car to make sure it didn't get corrupted when the battery died. Drove perfectly fine, and I logged it, everything seemed proper. So idk, really curious to see what the dealership says.

They will say you are all just f'd.

How much do they want to replace it?
You aren't going anywhere without one.

maddoggyusa · 10-12-2016, 01:05 AM

check the fluid level

Then I'd probably take it to a shop and have them scan the vehicle. Could be a module/sensor/electrical problem.

pump905 · 10-12-2016, 01:15 AM

maybe u hit the tap shift mode and did not realize it. see if it happens in Drive mode

Viper54 · 10-12-2016, 10:12 AM

I hope you seated the trans filter properly, might have been sucking air

Dmpsix · 10-12-2016, 10:15 AM

Since we're on the subjects of L99.

Someone here (I can't remember where I saw it) posted that using the tapshift and shifting through the gears at 4k - 6k and then letting it decelerate all the way down to 2k before downshifting was unnecessary stress on the transmission.

Is that true?

I like tapshift and making it sound like I have a manual transmission when I downshift lol.

CFD · 10-12-2016, 10:21 AM

It sounds like there may be an electrical issue that may be affecting the tapshift feature or the TCM.

Ace0751 · 10-12-2016, 10:46 AM

Quote:

Originally Posted by Dmpsix

Since we're on the subjects of L99.

Someone here (I can't remember where I saw it) posted that using the tapshift and shifting through the gears at 4k - 6k and then letting it decelerate all the way down to 2k before downshifting was unnecessary stress on the transmission.

Is that true?

I like tapshift and making it sound like I have a manual transmission when I downshift lol.

It's uneccessary stress and a stupid thing to do.

10-11-2016, 06:59 PM	#1
Myke783 Drives: 2010 Camaro 2SS/RS Join Date: Mar 2011 Location: the woodlands, tx Posts: 13 View My Garage	Transmission started going crazy! L99 So just flew back in town, from Business. Excited bc it's my birthday, but more so coming home to my beautiful Camaro lol. Went for a drive, and within 5 miles the car decided to have a mind of its own. I was cruising 65ish in Sport mode. When my transmission just decided to jump to like 3rd, then to 4th, and continued in a unpredictable pattern. Then it locked up on me, as did the rear tires, then it engaged back into gear. I immediately pulled to the shoulder. To figure out what the hell just happened. I noticed that the car will no longer go into reverse, in neutral it tries to coast at low speeds. I was able to get it home in manual mode. But if I tried to go into 5th or 6th, the rpm's would start going crazy again. I'll be taking it to the dealership within the next few days. You guys have any ideas or guesses as to what the issues may be? I've felt transmissions slip, and torque converters shudder. But the way this was, it seemed like possible computer ecm/tcm issues? And possible transmission issues now?

10-11-2016, 07:09 PM	#2
hunter1660 Drives: 2011ss/rs camaro Join Date: Sep 2011 Location: florida Posts: 1,261	Did you buy the car new? Is it tuned? It sounds like your on the right track with your diagnosis __________________ . OBX LTH,Rotofab,Magnuson Heartbeat.AEM wideband, HP Tuners

10-11-2016, 09:34 PM	#3
Cyber10 Drives: 2010 Camaro 2SS/RS Join Date: Mar 2016 Location: Indianapolis Posts: 288	When my transmission died it did almost exactly the same as your except I was doing about 40 up a ramp to get onto the interstate. My car shifted up and down a few times before I heard a thud and I had no more power below 4 gear, fortunately I made it over the ramp and got up into 6th and didn't hit traffic on my way to work and was able to get it to a shop later that day. I have no clue what exactly went wrong with mine as I chose not to rebuild it and bought a new one instead, tuner agreed that whatever the problem was it was definitely the transmission(as if it was even a question after seeing them pulling shards of metal out of my converter lol). Seems like the only difference between us is my low gears went while you're having problems with higher gears. Let us know what the dealer ends up saying, I'm genuinely curious as to what it is/what mine could have been. __________________ 491 hp/438 tq LS3 Conversion \| Comp Cam Custom Grind \| Mast Heads \| Comp Cam Push Rods \| LS7 Timing Chain \| 180 Thermostat \| Ported Intake \| Ported TB \| SLP UDP \| K & N CAI \| Custom 3800 Stall Converter \| Aluminum 1 Piece Driveshaft \| Kooks 1 7/8" LTH \| High Flow Cats \| ARH 3" Exhaust \| ARH Mufflers \| Eibach Lowering Springs \| BMR Floor Brace Subframe Connectors with Tunnel Brace \| BMR Moly Lower Rear Control Arms \| Oracle LED Halo Kit

10-12-2016, 01:15 AM	#10
pump905 Drives: 2011 2ss/rs black with white rally Join Date: Apr 2012 Location: il Posts: 303	maybe u hit the tap shift mode and did not realize it. see if it happens in Drive mode __________________

10-11-2016, 10:40 PM	#4
chuckie669 Drives: 2011 ss Join Date: Sep 2015 Location: E-TX Posts: 764	Eek... that sucks. How many miles do you have on your 2010 if i may ask?

10-12-2016, 12:02 AM	#5
CamaroFred Drives: Miss Con Ception Join Date: Aug 2016 Location: Chicagoland Posts: 2,998	Drop the pan and change the fluid and filter. You might get a few more months out of it.

10-12-2016, 12:12 AM	#6
Myke783 Drives: 2010 Camaro 2SS/RS Join Date: Mar 2011 Location: the woodlands, tx Posts: 13 View My Garage	I bought her new. I had a dyno tune done years ago when I did LT Headers, etc. But have tuned her with my Diablo sport trinity doing custom ecm/tcm tunes. But never adjusted the tcm tune, other than disabling torque management. However, my battery has been flaking out here and there. It did it, when I tuned it a few months back. But I re-tuned the car to make sure it didn't get corrupted when the battery died. Drove perfectly fine, and I logged it, everything seemed proper. So idk, really curious to see what the dealership says.

10-12-2016, 12:16 AM	#7
Myke783 Drives: 2010 Camaro 2SS/RS Join Date: Mar 2011 Location: the woodlands, tx Posts: 13 View My Garage	I just hit 85k miles. I changed my trans filter, changed the gasket, and put new fluid in it back in April.

10-12-2016, 01:05 AM	#9
maddoggyusa Drives: 2013 Camaro Dusk 2SS/6 Join Date: Sep 2013 Location: New Jersey Posts: 1,586	check the fluid level Then I'd probably take it to a shop and have them scan the vehicle. Could be a module/sensor/electrical problem.

10-12-2016, 10:12 AM	#11
Viper54 Drives: 2014 Camaro SS V8/L99 Join Date: Aug 2014 Location: Warren, Michigan Posts: 21	I hope you seated the trans filter properly, might have been sucking air

10-12-2016, 10:15 AM	#12
Dmpsix Drives: Black L99 2SS/RS Join Date: Mar 2014 Location: San Antonio, TX Posts: 1,862	Since we're on the subjects of L99. Someone here (I can't remember where I saw it) posted that using the tapshift and shifting through the gears at 4k - 6k and then letting it decelerate all the way down to 2k before downshifting was unnecessary stress on the transmission. Is that true? I like tapshift and making it sound like I have a manual transmission when I downshift lol.

10-12-2016, 10:21 AM	#13
CFD Drives: 2SS/RS L99 BLACK Join Date: Apr 2010 Location: Franklin , MA Posts: 6,696	It sounds like there may be an electrical issue that may be affecting the tapshift feature or the TCM.