Circuit Description
The automatic transmission (AT) clutch pressure control (PC) solenoid valve 1 is attached to the exterior of the transmission case. Upon receiving a linear current signal from the powertrain control module (PCM), it converts the modulated pressure to a regulated control pressure and supplies it for use in the pressure regulation, using the spring P at the clutch PC valve. The linear current from the PCM is output to the clutch of an appropriate gear position as determined by the shift schedule, so that a clutch control pressure appropriate for the driving condition is supplied. When the linear current from the PCM is on the high current side, the AT clutch PC solenoid valve 1 operates and the pressure regulated control pressure shifts to the high pressure side, ON. When the linear current is on the low voltage side, the AT clutch PC solenoid valve 1 stops operating and the pressure regulated control pressure shifts to the low pressure side, OFF. The PCM monitors mainshaft to output shaft speed ratio in the gear positions determined by the shift schedule.
When the PCM detects an incorrect ratio for the commanded gear, DTC P0746 sets. DTC P0746 is a type B DTC.