Circuit Description
The automatic transmission (AT) clutch pressure control (PC) solenoid valve 1 is mounted to the transmission case. Upon receiving a linear current signal from the powertrain control module (PCM), the PC solenoid valve 1 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 PC 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 regulation 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 P0747 sets. DTC P0747 is a type B DTC.