Circuit Description

WARNING: This page does not describe the selected car, but rather 12 other vehicles, including the 2002 GMC Savana Special, 2002 GMC Savana Camper Special, 2002 GMC Savana, 2002 Chevrolet RV Cutaway, and 2002 Chevrolet Cutaway. However, it is still accessible from the selected car via links, so may be relevant.

The PCM energizes the Torque Converter Clutch Pulse Width Modulated (TCC PWM) solenoid valve by closing the control circuit. This blocks the exhaust for TCC signal fluid and allows filtered 2-3 drive fluid to feed the TCC signal circuit. When the vehicle's operating conditions are appropriate for TCC application, the PCM begins the TCC duty cycle to approximately 30 percent. This allows TCC signal fluid pressure to move the converter clutch shift valve into the apply position and direct regulated apply fluid to the torque converter. The PCM then increases (ramps) the duty cycle to approximately 60 percent, where regulated apply fluid pressure, applies the converter clutch. The vehicle application determines the TCC apply rate. Once the TCC applies, the duty cycle immediately increases to approximately 70 percent to achieve full apply pressure, in the regulated apply fluid circuit.

The TCC PWM solenoid valve is de-energized by the PCM opening the control circuit. This action allows the TCC signal fluid to exhaust through the solenoid and blocks filtered 2-3 drive fluid from entering the TCC signal circuit. The loss of fluid pressure in the TCC signal circuit releases the TCC.

If the PCM detects high TCC slip when the TCC is commanded on, then DTC P0741 sets. DTC P0741 is a type "C" DTC. For California emissions vehicles DTC P0741 is a type "B" DTC.