Line Pressure Oddity

[arubenstein]

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]

For all reading, this is being dealt with via Email too.....

[arubenstein]

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]

If it's ok, just correspond here in this thread...

[GMPX]

Sorry, we sent the Email to the wrong address, I resent everything last night.

Cheers,
Ross

[arubenstein]

Any updates on this?

[GAMEOVER]

I have the same oddity in my pressure's....

[joecar]

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]

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]

My cal is a 2008 2WD 1500 Silverado 6.0ltr(L76) w/4L70E ECM=E38 & TCM=T42......

[arubenstein]

Then you probably have the same issue as I.

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

[GAMEOVER]

Yes, sir.........

[arubenstein]

Yes, sir.........

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

[GAMEOVER]

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]

The base shift pressure for 3-4 was fine in 7.5.4 build 66 though.....:)

[arubenstein]

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.