PDA

View Full Version : Line Pressure Oddity



arubenstein
August 9th, 2008, 01:26 PM
Hi,

T42 with a 4L70E in a 08 Suburban.

From the factory, the base line pressures for 1-2 and 2-3 shift (D8101, D8201) are shown as 90 PSI for all pressure patterns and all delivered engine torque. This is the only time I have ever seen this.

Does this seem right?

GMPX
August 10th, 2008, 10:19 AM
For all reading, this is being dealt with via Email too.....

arubenstein
August 10th, 2008, 11:45 PM
I tried to send you a PM but I am not allowed to ...

FYI, just wanted to let you know that I haven't gotten any emails from you guys. Maybe I missed it?

joecar
August 11th, 2008, 02:00 AM
If it's ok, just correspond here in this thread...

GMPX
August 11th, 2008, 10:04 AM
Sorry, we sent the Email to the wrong address, I resent everything last night.

Cheers,
Ross

arubenstein
August 23rd, 2008, 02:00 PM
Any updates on this?

GAMEOVER
September 25th, 2008, 07:13 AM
I have the same oddity in my pressure's....

joecar
September 25th, 2008, 07:31 AM
I have seen the shift pressures set to 90+ psi in various manual transmission files...

Is this what could have happened... GM accidentally used the wrong cal files...?

arubenstein
September 25th, 2008, 11:19 AM
At least in the cal I am working on (4L70E on a 08 Suburban w/T42)

And Ross knows about it. Last I heard from him is that they are still looking at it.

GAMEOVER
September 25th, 2008, 11:50 AM
My cal is a 2008 2WD 1500 Silverado 6.0ltr(L76) w/4L70E ECM=E38 & TCM=T42......

arubenstein
September 25th, 2008, 11:51 AM
Then you probably have the same issue as I.

Is 1-2 and 2-3 all 90's?

GAMEOVER
September 25th, 2008, 12:05 PM
Yes, sir.........

arubenstein
December 1st, 2008, 10:31 PM
Yes, sir.........

For me, this is correct in 7.5.5 (Build 74).

GAMEOVER
December 2nd, 2008, 01:55 AM
Yeah the base shift pressure's 1-2 & 2-3 are all normal now, except for the 3-4 base shift pressure which is Maxed out at 90psi across the board......

GAMEOVER
December 2nd, 2008, 01:59 AM
The base shift pressure for 3-4 was fine in 7.5.4 build 66 though.....:)

arubenstein
December 8th, 2008, 04:22 AM
Yeah the base shift pressure's 1-2 & 2-3 are all normal now, except for the 3-4 base shift pressure which is Maxed out at 90psi across the board......

This is the same in HPT. I believe this is correct.