Component Diagnostic Charts (C-Charts) - Port Fuel Injection

Chart C-8A - Torque Converter Clutch:

Wiring Diagram for Chart C-8A - Torque Converter Clutch:

CHART C-8A - TORQUE CONVERTER CLUTCH

Circuit Description:


The purpose of the torque converter clutch feature is to eliminate the power loss of the torque converter stage when the vehicle is in a cruise condition. This allows the convenience of the automatic transmission/transaxle and the fuel economy of a manual transmission/transaxle.

Fused battery ignition is supplied to the TCC solenoid through the brake switch, and transmission/transaxle third gear apply switch. The ECM will engage TCC by grounding CKT 422 to energize the solenoid.

TCC will engage when:

^ Engine warmed up

^ Vehicle speed above a calibrated value. (About 32 mph 51 km/h)

^ Throttle position sensor output not changing, indicating a steady road speed.

^ Transmission/transaxle third gear switch closed

^ Brake switch closed


Test Description: Numbers below refer to circled numbers on the diagnostic chart.

1. Light "OFF" confirms transmission/transaxle third gear apply switch is open.

2. At 25 mph the transmission/transaxle third gear switch should close. Test light will come "ON" and confirm battery supply and closed brake switch.

3. Grounding the diagnostic terminal with ignition "ON," engine "OFF," should energize the TCC solenoid by grounding CKT 422. This test checks the ability of the ECM to supply a ground to the TCC solenoid. The test light, connected from 12 volts to ALDL terminal "F", will turn "ON" as CKT 422 is grounded. Solenoids and relays are turned "ON" or "OFF" by the ECM internal electronic switches called "drivers." Each driver is part of a group of four called quad-drivers. Failure of one can damage any other driver within the set. See CHART C-1.