2005 Impala/4T65 surge

[The_Eric]

I've got a question for the resident trans gurus - I have a customer with a 4T65 and P1811 code that it surging under load once warm and the converter locks up. I see varying converter slip on the scan tool and lightly resting your foot on the brake pedal pulls the converter clutch command and eliminates the surge.. So... any chances the converter clutch is still good? Is this usually a clutch issue, solenoid issue or EPC???

Would pulling it and installing the TransGo kit plus the EPC and converter clutch solenoids fix the issue?

 

[Trav]

Demarpaint had the same code/issue on one of these, I watched the shift times on a scan tool and they were long, we put a shift kit in and it reduced them to normal times and took care of it. AFAIK (he can chime in) it went for years and a lot of miles without any issue.
It may be a hail Mary but I think it is worth a try.

 

[clinebarger]

The EPC can cause line pressure oscillation, Throwing in a TransGo kit, EPC, And the TCC PWM Solenoid is worth a shot.

 

[clinebarger]

A line pressure gauge is an invaluable diagnostic tool, But you need to clear P1811 if current/hard as it will max the EPC by cutting current to it.
@1 amp of current is minimum line pressure.
@Zero current is maximum line pressure.

 

[The_Eric]

What pressures would a guy expect to see?

 

[The_Eric]

Thoughts on this kit here? Also what do you suppose the odds are that the converter is still happy?

Solenoid Kit