8L90-E problems My tuner has never seen before.

Ltx_cuban · 08-31-2023, 07:06 AM

Recently installed FBO ported Lt2 im, zr1 tb, rotofab, and longtubes on my 2016 Camaro SS
Car was being tuned and something happened that the tuner has never seen. While in manual mode during a WOT pull the transmission tried to downshift to a lower gear so in fear of hurting the car the tuning had to come to a hold.
Shortly after the install was done I myself noticed the same thing while moving the car in manual mode, upshifted to third gear then all of a sudden I see its trying to downshift to 1st. Never occurred prior to bolt ons.
Any help would be greatly appreciated, my assumptions is the tcm is taking a crap

cjperformance · 08-31-2023, 07:16 AM

Was the TCM retuned, or stock?

If TCM is tuned, would need to look at the tune file to see if there are issues in the TCM tune.

Also (just guessing) but could potentially be a bad torque model in the ECU. Not sure if that would affect manual mode, more likely would affect auto mode, but thought id throw that out there. Does your tuner have experience with this SPECIFIC platform? Meaning Gen V engine.

If you hold the stick back in manual (TUTD) mode, it will try to find the lowest gear it can, so maybe check the wiring or mechanicals to see if something is causing it to think the stick or downshift paddle is being held back? Ive seen all kinds of vids on youtube JustRolledIn where things get jammed in shifters causing problems.

Ltx_cuban · 08-31-2023, 07:22 AM

Tcm is stock never touched.
And yes the tuner is very experienced on this platform.

Ltx_cuban · 08-31-2023, 07:31 AM

Quote:

Originally Posted by cjperformance

Was the TCM retuned, or stock?

If TCM is tuned, would need to look at the tune file to see if there are issues in the TCM tune.

Also (just guessing) but could potentially be a bad torque model in the ECU. Not sure if that would affect manual mode, more likely would affect auto mode, but thought id throw that out there. Does your tuner have experience with this SPECIFIC platform? Meaning Gen V engine.

If you hold the stick back in manual (TUTD) mode, it will try to find the lowest gear it can, so maybe check the wiring or mechanicals to see if something is causing it to think the stick or downshift paddle is being held back? Ive seen all kinds of vids on youtube JustRolledIn where things get jammed in shifters causing problems.

Thanks man I’ll take a look at justrolledin

08-31-2023, 07:06 AM	#1
Ltx_cuban Drives: Chevrolet camaro ss Join Date: Jun 2023 Location: Florida Posts: 5	8L90-E problems My tuner has never seen before. Recently installed FBO ported Lt2 im, zr1 tb, rotofab, and longtubes on my 2016 Camaro SS Car was being tuned and something happened that the tuner has never seen. While in manual mode during a WOT pull the transmission tried to downshift to a lower gear so in fear of hurting the car the tuning had to come to a hold. Shortly after the install was done I myself noticed the same thing while moving the car in manual mode, upshifted to third gear then all of a sudden I see its trying to downshift to 1st. Never occurred prior to bolt ons. Any help would be greatly appreciated, my assumptions is the tcm is taking a crap

08-31-2023, 07:16 AM	#2
cjperformance Drives: 2017 Camaro SS 50th Anniversary Join Date: Apr 2021 Location: Missouri Posts: 950	Was the TCM retuned, or stock? If TCM is tuned, would need to look at the tune file to see if there are issues in the TCM tune. Also (just guessing) but could potentially be a bad torque model in the ECU. Not sure if that would affect manual mode, more likely would affect auto mode, but thought id throw that out there. Does your tuner have experience with this SPECIFIC platform? Meaning Gen V engine. If you hold the stick back in manual (TUTD) mode, it will try to find the lowest gear it can, so maybe check the wiring or mechanicals to see if something is causing it to think the stick or downshift paddle is being held back? Ive seen all kinds of vids on youtube JustRolledIn where things get jammed in shifters causing problems. __________________ 2017 50th Anniversary Edition \| P1X Stage 2 DSX Aux Low Side \| LT4 high side \| Flex Fuel TooHighPsi Port Injection (installed & tuning) CircleD 3K Stall \| QA1 CF Driveshaft Forgestar F14 Drag 17x10 NT555R2 305/45/17 Rear Forgestar F14 18x8 NT555G2 235/50/18 Front 10.84@131 w/4.13" pulley ??.??@??? w/3.7" pulley (installed & tuning)

08-31-2023, 07:22 AM	#3
Ltx_cuban Drives: Chevrolet camaro ss Join Date: Jun 2023 Location: Florida Posts: 5	Tcm is stock never touched. And yes the tuner is very experienced on this platform.

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