Scott Mcelfresh

Can anyone help me find the cause of my trans not working correctly. Trans shop says it's the tune. I'm not sure how to attach the tune to a post.

mrvedit

You have HP Tuners?
If yes, first scan for codes and then use the scanner to log "Trans gear", "TCC", "Trans temp", speed, MAF frequency, MAP and TPS %.
Often a code or engine sensor problem will prevent the PCM from commanding 4th gear or TCC lockup.

Scott Mcelfresh

I have EFI live v2 flashscan but I'm new to that also so right this minute I'm trying to figure out how to load pids.

mrvedit

If you have an external cooler, make sure it is not touching the radiator.
We've had a few threads with similar symptoms caused by the trans overheating because the cooler was too close to the radiator.

See this thread and especially the resolution in post #8:

https://ls1tech.com/forums/automatic...t-does-do.html

Scott Mcelfresh

OK now that I have a minute here is my build
lq9 ,243 heads, BTR stage4 cam, ls6 intake, long tubes, 3 inch true dual with an x and dynomax race bullets, 4l60e suppose to be built-up, beast shell, Vette servo, 4l65e planetary setup, 3600 stall,
393rwhp and 390ish TQ
I took the car to the trans shop because I lost 4th and lockup. They checked the converter and it looked good. They went through the trans for the 3rd time and told me to come pick it up because everything was working correctly. Shifting great and locking up like it is supposed to. When I drove the car home I had gotten about 25 miles away when I realized it wasn't shifting out of 3rd. Most of those were city miles so it didn't concern me right away.
Once it clicked in my head I called the shop and they said it was in the tune. I guess I must have a very rare 98 pcm that adapts to the drivers butt and recalibrates shifting and tcc lockup. So I have no dtcs and for some reason my scanner says that it is enabling lockup but it's not locking and no 4th gear.
The tune has been the same since before the second time the trans was built. I literally do not have 400 miles on the transmission. I'm learning how to load pids and data log so hopefully I'll have some more information soon. If there is anything specific I should record let me know. And as for the trans gear PID what exact one do I load there are 2.

mrvedit

I'm not familiar with EFI-Live to give you help there, but one PID might be what position the shifter is in and the other PID is what gear the PCM has commanded.
Having said that, be sure your shifter is adjusted correctly; check that Neutral really is Neutral and not OD.

Scott Mcelfresh

Tcc mode reads enabled in 3rd gear at around 40mph and 20% throttle. Turns off under acceleration and braking.
i will be data logging it later today for more pids
Map maf TPS tcc gear commands and trans temp

Scott Mcelfresh

ok I logged about 2 miles and it shows the pcm is commanding 4th and locking the converter. so is it a mechanical issue on the inside of my very fragile 4l60e? if anyone is interested in seeing the run file let me know I can email it. or if anyone is interested in looking at my current tune I can email that also ........so confused

RevGTO

iTrader: (12)

One thing you can do is compare your tranny tune to a stock tune for the same year in EFILive. But of course if the shifts and lock-up are being commanded and yet not executed, the problem does not lie in the tune.

mrvedit

I would have expected the trans shop to connect their scanner and confirm that the trans shifts and the TCC engages when commanded. A trans shop is "motivated" to find something wrong with the trans and yet they did not.

I would put the rear wheels up and command the gears, listening for the shifts and verifying each gear by comparing RPM and MPH.

Also I would measure the end play on the servo - while holding a ruler nearby press on the servo cover with a crowbar and estimate how much it moves. 1/16-1/8" is spec. 3/16" or more indicates a worn band which might prevent 4th gear from engaging.
If the end play is OK, it is very rare for just 4th gear to be lost. Even then usually 2nd is lost before 4th due to a worn band. A worn 4th gear servo piston seal or cracked piston could cause 4th to be lost, but even then the TCC should still work.

Scott Mcelfresh

I'm waiting on a response from the trans shop about my findings. Hopefully they will respond by Monday so I can get it back to them.

mrvedit

I assume you are following this very similar current thread:

https://ls1tech.com/forums/automatic...le-moving.html

Turns out his trans is either overheating or the temp sensor is inaccurate.

Scott Mcelfresh

im not having an issue with temperature checked that with the data log and it's accurate. All the bands are new also. I'm going to take it back to the trans shop and they can pull it apart again for the 4th time. It has a year warranty. If they fail to fix it again I will just ask for my money back. I'm definitely not a ASE certified mechanic but it seems like they really don't care to figure out what the issue is since they have already been paid.

Scott Mcelfresh

Dropped the car back off to the trans shop yesterday. Hopefully they figure out the issue. Everything is pointing to a mechanical or electrical issue on the inside so I will be patient and wait for their call.

Scott Mcelfresh

I was patient for a week and called the trans shop and they told me they haven't messed with it because they are waiting for a local tuner to look at my tune. He is supposed to be back in shop today. Hopefully he gets a chance to go through it and confirm the mechanical issue. I really didn't think this would take so long.

RevGTO

iTrader: (12)

There's really no need to be waiting a week for somebody to look a your tune when you can do it yourself with EFILive. As I suggested before, download your existing tune into EFILive and compare it to the stock tune for your car. If there are areas where your tune differs from stock, then you can discuss it here and with the tranny shop to see if that could be part of the problem. If the tune is stock, then the problem isn't in the "tune" per se and you don't need to be waiting for some tuner to come look at it (and charge you for it).

mrvedit

Right. You are welcome to post your tune here too. There are plenty of EFI users here who can quickly check if there is a tune problem.

Scott Mcelfresh

Joecar did me a solid and looked through my tune before I even took my car back to the shop. This has been an issue since the planetary came apart. The tune has been in the car for over a year and it worked fine. I'm just trying to help the trans shop by showing them it's something mechanical so they stop wasting my time and their own but I don't think they are listening to me.

RevGTO

iTrader: (12)

Well, if Joecar has given your tune a pass, you're good to go on that. The problem has to be electrical, mechanical, or hydraulic. The shop shouldn't waste time (or your money) on some "tuner" checking your tune.

Scott Mcelfresh

Trans shop is saying they replaced servo seals and now it has 4th but no lockup. So they are gonna replace the lockup selinoid. That was last week. Today they said that the line pressure is too high. Would that keep it from not shifting and locking up?

I'm starting to get the feeling that I chose the wrong shop to go through my trans.