I have a 79 Firebird with the LS1 and 4L60E from a 2000 Camaro in it. It upshifts to 4th gear at speeds as low as 5-6 MPH, and will not downshift into first unless you come to a complete stop. Even 100% throttle will not allow a downshift to 1st. I also do not know why it upshifts so fast. I have HP tuners and have been through all the shift schedules and there is nothing in the shift schedule to explain this behavior so I assume it is some kind of malfunction mode. It has a new VSS and gets a good clean signal from it.

It will stay in 1st gear if you select manual 1st with the shifter

Anyone ever seen this before?

Thanks, Dave

 

That is indeed a strange behavior, but since the trans will only shift when commanded by the PCM, it is a PCM or tuning problem.
Make sure you are looking at the correct shift tables, IIRC, there is one for Normal mode, Performance mode and Hot mode.
You should be able to figure this out and correct it with HP Tuners. You are welcome to post the tune here.

 

I see you've looked at the tune...what about live data?
What is it actually commanding whenever it happens?

 

Yes - I have logged data. It is achieving the commanded gears. For some reason it never tries to downshift to first.

 

I agree with what you are saying - but I have been through every table I can find and none of them had data that would explain this behavior. I even tried putting normal shift schedules into the D2 D3 maps to get it to behave normally. The only weird thing I have seen is that when in Manual first it shows "2" for the gear it is actually in. But rpm to mph behavior makes it clear that it is actually successfully engaging first gear. I will log some normal driving and post the logs and maps here.

 

Here is a calibration I was testing last night - I even tried putting normal shift data in the D1 D2 2nd and D2 3rd tables to see if that was causing it.

 

another test from this morning - cal file and log

 

Sorry my latest version HPTunder 4.63 will not open those file.

 

Yeah I have to run the newest beta versions to be able to tune the Toyota Trucks.

 

OK, I downloaded the Beta onto my desktop and can now read your files.
I agree that all your shift tables look OK.
From the logging I see that it has already shifted into 4th by 8mph with 0-4% throttle position. Your speed, TPS, shifter position and commanded gear all seem to be reporting correctly.
At 10:07:15.00 I see that shortly after you go WOT at 20 mph it shifts from 4th into 3rd, but clearly should be shifting down to at least 2nd.
My conclusion, more like a guess, is that either the HPT Beta is writing the wrong shift tables, or the PCM is defective or scrambled.

Do you have an older working tune for this car?
Personally, I would install HPT release version on a laptop, and either write a previous tune or even stock tune into the PCM. (Obviously you might have to make some minimal updates to a stock tune if the engine is modded.)

 

I do not have a stock cal for it - the car came here with shifting problems. If someone has a stock 2000 Camaro ROM I would love to try writing it and I will edit the shift tables with non beta software.

 

Attached is a stock tune for a 2002 Camaro which should be close to what you need.
I couldn't find it today, but HPT used to have a repository of stock tunes.

 

The repository was moved to only be displayed once you login to the support site.

 

Trans Revolutions/Mile is way off.

Is there a reason you have an odd rear gear ratio and odd transmission ratios?

 

A 2002 file won't work in a 2000

 

Stock 2000 Camaro LS1 tune file

 

Your tune file or PCM is corrupt.
Every time I've come across a corrupt file it has a y in the calibration details, somewhere. Like your VIN here.

 

First, WELCOME to the forum.
Next, thank you for your immediate contributions. Impressive catch to notice the corrupted VIN and knowing this indicates a corrupt file.
Not sure if the Trans Revolution/Mile matters because it was reporting a reasonable SAE Speed. However none of us knows exactly what values the PCM uses for various calculations; always best to keep all of them correct.

 

Did you ever solve this problem?
My LS Swap with 4l60e is doing a similar thing in that it upshifts to 2nd, 3rd and 4th immediately.
Wondering if you go your answer.

 

What do you mean? What is the difference? Wondering if this could be my problem.