97 GTP PCM controlling 4T60e

[hitman92499]

I recently did a top swap on my 97 Grand Prix GT. I'm using the 97 GTP PCM from the donor vehicle. I changed all the tables in the trans files to 97 GT factory data, but for some reason the GTP PCM still will not shift the trans from 2nd to 3rd and 3rd to 4th. Also, if I put the vehicle manually in 1st, it will still shift to 2nd. I would've just put the L67 engine data on my L36 PCM but I have the serial version of HP Tuner and my OSID is not supported as I have an early 97 Grand Prix. I've even gone to the extent of tracing wiring diagrams. I'm just lost and need some direction. Any help?

[wyochimneysweep]

some 97 4t60e trans used a vacuum modulator and the later 4t60e used a pwm solnoid to control line pressure via the pcm. I'm thinking the gtp pcm is for a later 4t60e and you have one with a vacuum modulator. Or is it possible the GTP had the 4t65e? I'm currently have a problem with a 4t60e that will slip in first in overdrive but not all the time. put it in drive and it never slips. books shows all the same things are applied and holding.

[hitman92499]

As far as I know, all of the 4T60e transmissions operated shift pressure using the vacuum modulator, and all of the 4T65e transmissions had the solenoid. All 1997-up GTP's came with the 4T65e-HD. My only other options at this point are to 1) use a DHP, or 2) get a PCM from a later 1997 SE/GT with the L36 that I can program.

Your issue, on the other hand, sounds like a worn, internally leaking valve body possibly causing the problem.

[bilemke]

A different PCM from a SE/GT will not help. The Grand Prixs from 98+ all used a 4t65e of some sort.

in 1997, the GTP's used the 4t65e (HD).. The GT's were a oddity that used the 4t60e..

Use a 97 GT file and alter the engine portion of the programming to or get someone (with another tuner unfortunately) with some more advanced skills to take a 97 GTP bin and swap out all the trans settings (and I do mean all, not just what can be seen in HPT).

[murphinator]

A different PCM from a SE/GT will not help. The Grand Prixs from 98+ all used a 4t65e of some sort.

in 1997, the GTP's used the 4t65e (HD).. The GT's were a oddity that used the 4t60e..

Use a 97 GT file and alter the engine portion of the programming to or get someone (with another tuner unfortunately) with some more advanced skills to take a 97 GTP bin and swap out all the trans settings (and I do mean all, not just what can be seen in HPT).

could he ask hpt to do a segment swap for him possibly ?

[hitman92499]

Bilemke, if I'm reading this right, you're saying copy a stock 97 GT file onto my GTP PCM, then change all of then engine parameters back to the L67? Could it be that easy?

[glanzergtx]

Bilemke, if I'm reading this right, you're saying copy a stock 97 GT file onto my GTP PCM, then change all of then engine parameters back to the L67? Could it be that easy?

I can look at my database of bins this weekend and see if i have a 97 GT file. I already know i have a 97 zzp GTP file. But obviously would need to change the trans settings.

Let me see what i can find for ya

[hitman92499]

I tried Bilemke's suggestion and the GTP PCM will now control my 4T60e without a problem. Now, my boost gauge on the DIC has disappeared which leads me to believe it is no longer controlling the BCS and allowing me to boost. I'm one step ahead of square one, but far from the next step I guess.

UPDATE: The Tech II confirms that my PCM is no longer controlling the boost control solenoid. Is there any way to make it control it again with the HPT other than reflashing the GTP stuff back on?

[bilemke]

I tried Bilemke's suggestion and the GTP PCM will now control my 4T60e without a problem. Now, my boost gauge on the DIC has disappeared which leads me to believe it is no longer controlling the BCS and allowing me to boost. I'm one step ahead of square one, but far from the next step I guess.

UPDATE: The Tech II confirms that my PCM is no longer controlling the boost control solenoid. Is there any way to make it control it again with the HPT other than reflashing the GTP stuff back on?

It is not controlling the boost because of the way you did it. You didnt copy all the GTP's engine config. Again, this takes a fair bit of editing that the HPT program can not do right now. Without the help of another tuner and someone capable of dong something like a "segment swap" (not really segment like the v8 guys have, but close), you only have a 97 GT bin with some of the GTP/L67 engine settings. One such setting missing is the one that defines if there is a supercharger to control.

The opposite, if you were to use a GTP bin and try copying trans settings over, would not work simply cause there is a byte that defines what transmission is being controlled (and isn't updated even by copying all the trans settings accessible with HPT right now).

[hitman92499]

Well, regardless, it works ok for now. The GTP data is getting me around 30 mpg on the highway, and I only saw 5* of knock under boost which isn't bad considering I haven't actually "tuned" it yet. For now, I'll just keep my foot out of it and hope maybe the DHP can do more for me than the HPT has.

[sandrock]

I wish I caught this post earlier. My first dabbling with tuning and Frankensteining was with a Series 1 L67/4T60e being run under OBD2 control. I ran a '97 PCM, and first used the L36 file to control the trans, which it did but lost boost control. Went to an L67 file and got boost control and a very wonky transmission.

I ended up using the L67 file, rewired the -60 to mimic the -65e as far as the solenoids are concerned, zeroed out all the tables specific to the -65e (pressure control solenoid and the pressure transducer, and the switching manifold), set no reporting to anything that was specific to the -65e, and hoped for the best.

It worked...so maybe try what I had done.

[TGP-37]

I recently did a top swap on my 97 Grand Prix GT. I'm using the 97 GTP PCM from the donor vehicle. I changed all the tables in the trans files to 97 GT factory data, but for some reason the GTP PCM still will not shift the trans from 2nd to 3rd and 3rd to 4th. Also, if I put the vehicle manually in 1st, it will still shift to 2nd. I would've just put the L67 engine data on my L36 PCM but I have the serial version of HP Tuner and my OSID is not supported as I have an early 97 Grand Prix. I've even gone to the extent of tracing wiring diagrams. I'm just lost and need some direction. Any help?

The 4t60e will manually shift 1 to 2 incase the PCM will not. Like a fail safe.

The PCM file has a table for transmission type.

This would likely be the problem if the donor PCM was controlling another trans type.

Get Tiny Tuners to change the trans type, but you need a .BIN file, Maybe HPT Staff can help.

UPDATE: Here is that thread (scroll down to my update) http://www.hptuners.com/forum/showthread.php?t=33669