I have a 1994 camaro with 4l60e. Car has a cam , 3200 stall and bolt ons. At the track at WOT car will shift from 1st to 3rd. After the run the car stays in 3rd until car is turned off for about ten minutes, then will shift fine again. Is this fail safe mode or limp mode? Computer was tuned by ed Wright and found no issues. Car was placed on chassis dyno and would shift perfectly, only happens at the track. Although if I restart the car after a burnout I can only manual shift to get the car to go into second gear, but after run still will be stuck in 3rd. Tried using a scanner (red brick snap-on) going down the track and go no new DTC. Has four DTC while key-on , ECM PROM error, code for no knock sensor, high voltage, and emissions code. Transmssion fluid is new and full too, solenoids work, and engine has maybe 1000kms on it. This only started happening after new converter was installed.

 

What are the exact DTC codes for the four you found?

Looking at the factory service manual, a code for "System Voltage High" (DTC 53) can cause a problem with "3rd gear only".

Free download of factory service manual, courtesy of GaryDoug:

http://www.mediafire.com/?40mfgeoe4ctti


There's a lot of 4L60E diagnostic and trouble shooting info in the factory service manual, Volume 1 of 2, Part 1 of 2, Section 7A-14A, on pages 7A-14A-38 through -49.

Then there are detailed descriptions for the auto trans trouble codes in Volume 2 of 2. Shoebox has a good summary of transmission specific codes, including non-transmission codes that affect the default actions of the trans: I know you indicate there are no trans codes, but as you can see from the high voltage issue, the trans can be affected by other codes.

http://shbox.com/1/Dtcs.htm

Be sure to select the "OBD-I Transmission Codes" tab at the bottom of the opening page.

 

Sorry for late reply, if the high voltage problem is the issue why would it not go 3rd gear only on the dyno. I can also turn the car off and back on after the burnout and manual shift the car and then I can get it into second gear fine.

 

Maybe the code clears, and the vehicle does not experience high voltage on the alternator. Then you get a voltage flare on the system, and it screws things up.

I'm looking at a very brief description of a problem I've never seen before in the 20+ years I've been helping on this site. I'm no auto trans expert. I'm just trying to offer suggestions on what the problem may be. There aren't may people left on this site with the knowledge to help. I'm trying. Rather than reject my comments out of hand, maybe take a look at the factory service manual. And, you couldn't even take the time to post the numerical codes.

 

Sorry for being too brief, I appreciate the assistance very much . The only not normal code is DTC 53 system voltage high, I did check the manual and says will cause 3rd gear only. Odd that it always shows the code even if the key is on, but only causes 3rd gear only at WOT when driving at track. Could the new battery I installed be an issue with high voltage ?

 

Sounds like you've found the "stall wall". The pcm see a discrepancy between rpm and vss then goes into limp mode.
Need to tune it out.
https://www.ls1lt1.com/forum/automat...-sticking.html
Few questions on my 1st LT1 tune

 

I assumed I would have stall wall issue with the new converter, so I sent the computer to ED WRIGHT and he said he already tuned it to not have this problem

 

The VSS diagnostic enable rpm was at 3000rpm , so I changed it to 4000rpm hopefully this fixed my issue, thanks for the replies.