Chart C-8 Torque Converter Clutch (TCC) Diagnosis

Chart C-8A:

Torque Converter Clutch Wiring Schematic:

CIRCUIT DESCRIPTION
The torque convertor clutch (TCC) system is designed to eliminate power loss by the converter (slippage) thus increasing fuel economy. By locking the torque converter clutch, a more effective coupling to the flywheel is achieved. The torque converter clutch is operated by a Powertrain Control Module (PCM) controlled solenoid located inside the automatic transaxle.

CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.

1. This test should be performed with the aid of a helper, to operate the Tech 1 and observe the RPM fluctuation.

Fused battery ignition is supplied to the TCC solenoid through the brake switch. The PCM will engage TCC by grounding CKT 422 to energize the solenoid. TCC will engage when:

^ Vehicle speed is greater than 35 mph with A/C "OFF," 44 mph with A/C "ON."
^ Engine at normal operating temperature above 20°C (68°F).
^ Throttle Position (TP) sensor output not changing, indicating a steady road speed.
^ Brake switch closed.
^ 3rd gear switch applied.