Circuit Description
WARNING: This page is about a different car, the 2002 Buick Regal, 2002 Buick Century, 2001 Buick Regal, and 2001 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
The 2-3 shift solenoid valve is supplied with fused ignition voltage. The ground path is controlled by the PCM. When the PCM commands the solenoid off, a ground path is not provided and the filtered line pressure that is fed to the solenoid is exhausted. When the PCM commands the solenoid on, a ground path is provided and the exhaust port is blocked, stopping the exhaust of line pressure.
The PCM identifies a 2-3 shift solenoid valve performance condition by monitoring the commanded gear versus the gear ratio.
If the PCM detects a 2nd gear ratio when 3rd gear is commanded and a 1st gear ratio when 4th gear is commanded, then DTC P0757 sets. DTC P0757 is a type "A" DTC.