Component Diagnostic Charts (C-Charts) - Throttle Body Fuel Injection

Chart C-8A:

Wiring Diagram For TCC Circuit:

CIRCUIT DESCRIPTION:

The purpose of the automatic transmission Torque Converter Clutch (TCC) feature is to eliminate the power loss of the torque converter when the vehicle is in a cruise mode. This allows the convenience of the automatic transmission and the fuel economy of a manual transmission. Fused ignition voltage is supplied to the TCC solenoid through the brake and third gear switches. The ECM will engage the TCC by grounding circuit 422 to energize the solenoid.

The TCC will engage when the following conditions exist:
1. Vehicle speed above 23 mph (37 km/h) with A/C "OFF" (35 mph with A/C "ON").
2. Engine coolant temperature exceeds 30°C (86°F).
3. Throttle position sensor output is not changing faster than a calibrated rate (steady throttle).
4. Transaxle third gear switch closed.
5. Brake switch closed.