Circuit Description

Torque Converter Clutch (TCC) Pulse Width Modulated (PWM) solenoid is a normally closed solenoid used to control apply and release of converter clutch. PCM operates TCC PWM solenoid with a negative duty cycle. When vehicle operating conditions are appropriate to apply TCC, PCM immediately increases duty cycle to about 42 percent. PCM then increases duty cycle to about 90 percent to achieve full TCC apply pressure. When solenoid is commanded on, PCM will detect high voltage. When solenoid is commanded off, PCM will detect low voltage. DTC P1860 will set when PCM detects a continuous open, short to ground or short to voltage in TCC PWM solenoid circuit.