Circuit Description

Direct clutch speed sensor detects direct clutch drum speed and sends signals to ECM. Shift timing, engine torque and hydraulic pressure is controlled by ECM based on signals from vehicle and direct clutch speed sensors. DTC is output when the following conditions are detected by ECM for 4 seconds or more: vehicle speed is 20 MPH or more, ECM does not detect an upshift, not sensing transaxle in "1", "2", "3" or "O/D" position, direct clutch (input shaft) speed is 300 RPM or less, output shaft speed is 1000 RPM or more, PNP switch signal is OFF, and shift and SL solenoid valves and vehicle speed sensor are okay. Possible causes are:

• Open or short in direct clutch speed sensor circuit.
• Direct clutch speed sensor malfunction.
• ECM malfunction.