Low transmission fluid level
Dirty transmission fluid
Faulty pressure control solenoid valve ‘C’
Pressure control solenoid valve ‘C’ harness is open or shorted
Pressure control solenoid valve ‘C’ circuit poor electrical connection
Engine Light ON (or Service Engine Soon Warning Light)
The pressure control solenoid valve ‘C’ is normally low pressure control solenoid. The solenoid is activated to control the apply and release of the 2nd brake and 1st and reverse brake, and torque converter clutch. Lock-up operation, however, is prohibited when A/T fluid temperature is too low. When the accelerator pedal is depressed (less than 1/8) in lockup condition, the engine speed should not change abruptly. If there is a big jump in engine speed, there is no lock-up.