Code P1745 - Line pressure too high for too long?

Hello,

P1745 Transmission Line Pressure Too High.
This DTC is an informational DTC to inform the tech that the transmission has been operating in an open-loop line pressure control for 2000 miles or 1000 2-3 upshifts resulting from a line pressure DTC.
The transmission is not designed to operate in open-loop line pressure control for an extended period time. This DTC is intended to protect the transmission. If the DTC sets, the transmission controller will place the transmission into limp-in mode. In order to erase this DTC you must reset (erase) the VLP shift counter and the output tooth counter which is a single procedure under Miscellaneous functions in the scan tool called “Clear Variable Line Pressure (VLP) counters”.
The line pressure sensor (2) is mounted on the top of the valve body, next to the pressure control solenoid (1). The TCM utilizes a closed-loop system to control transmission line pressure. The system contains a variable force style solenoid, the Pressure Control Solenoid. The solenoid is duty cycle controlled by the TCM to vent the unnecessary line pressure supplied by the oil pump back to the sump.
The system also contains a variable pressure style sensor, the Line Pressure Sensor, which is a direct input to the TCM. The line pressure solenoid monitors the transmission line pressure and completes the feedback loop to the TCM. The TCM uses this information to adjust its control of the pressure control solenoid to achieve the desired line pressure.
See image below

To be able to clear VLP counters you will need to use a suitable diagnostic tool

Hope this helps.

Cheers, Boris