Torque Converter Operation Test

This test verifies that the torque converter clutch control system and the torque converter are operating correctly.

Carry out Quick Test with scan tool. For additional information, refer to RETRIEVING DIAGNOSTIC TROUBLE CODES (QUICK TEST) . Check for DTCs.
Connect a tachometer to the engine.
Bring the engine to normal operating temperature by driving the vehicle at highway speeds for approximately 15 minutes in D position.
After normal operating temperature is reached, maintain a constant vehicle speed of about 80 km/h (50 mph) and tap brake pedal with the left foot.
Engine RPM should increase when brake pedal is tapped, and decrease about five seconds after pedal is released. If this does not occur, see torque converter operation concerns. For additional information, refer to DIAGNOSIS BY SYMPTOM INDEX .
If the vehicle stalls in D or manual 2 at idle with vehicle at a stop, move the transmission range selector lever to manual 1 position. If the vehicle stalls, see torque converter operation concerns. For additional information, refer to Diagnosis By Symptom in this section. If the vehicle does not stall in D, refer to DIAGNOSIS BY SYMPTOM INDEX .
If the vehicle exhibits a vibration during the road test complete the Road Test Evaluation Form. See Fig 1 and Fig 2 . This form will aid the technician in determining the source of the vibration.

NOTE: The following is a list of common vehicle concerns that have been misdiagnosed as torque converter clutch shudder.

Fig 1: Torque Converter Road Evaluation Form (1 Of 2)

Courtesy of FORD MOTOR CO.

Fig 2: Torque Converter Road Evaluation Form (2 Of 2)

Courtesy of FORD MOTOR CO.