September 30, 2005
P1811 code or a slip/shudder condition can indicate a pressure control problem in the GM 4T65-E. A worn or sticking torque signal regulator valve and bore reduces or prevents line rise, resulting in long soft shifts and slippage. Reconditioning the bore and installing Sonnax oversized torque signal valve 84754-44 restores proper hydraulic clearances and function of the torque signal oil circuit.
To eliminate codes 1811 and 741and TCC-related issues, be sure to also inspect the actuator feed limit valve, boost valve assembly, TCC regulated apply valve and TCC apply valve. The PCM must be reset/relearned after any valve body repairs. Aftermarket scanner relearn procedure or battery disconnect for 12 hours may not restore drivability and line pressure control. Performing a dealer reflash or a web reflash is frequently the only method to properly restore control.
Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.