Torque Converter Clutch Operation Test

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

1. Carry out Quick Test; refer to On-Board Diagnostics with Diagnostic Tool . Check for DTCs; Refer to the DIAGNOSTIC TROUBLE CODE CHART .
2. Connect a tachometer to the engine.
3. Bring the engine to normal operating temperature by driving the vehicle at highway speeds for approximately 15 minutes in (D) position.
NOTE: Some applications (based on calibrations) may or may not disengage the torque converter clutch at road speeds, above 72 km/h (45 mph) when tapping on the brake. Some applications may or may not disengage the torque converter clutch at road speeds, above 72 km/h (45 mph) with closed throttle.
4. 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.
5. The correct operation of the TCC can be verified by using a scan tool and monitoring the TCC during the 4-3 coast down shift. Engine rpm should increase when brake pedal is tapped and decrease about five seconds after pedal is released. If this does not occur, refer to DIAGNOSIS BY SYMPTOM INDEX .
6. 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, refer to DIAGNOSIS BY SYMPTOM INDEX . Repair as required. If the vehicle does not stall in (D), refer to DIAGNOSIS BY SYMPTOM .