Transmission Converter Clutch (TCC) (2.8L "A" Body)

The 3rd gear switch is open both in 3rd and 4th gear. The 4th gear switch is open only in 4th gear, which allows for TCC when in 4th gear. The TCC will disengage during a 4-3 downshift.

1. Some "SCAN" testers display the state of these switches in different ways. Be familiar with the type of tester being used. Since both switches should be in the closed state during this test, the tester should read the same for either the 3rd or 4th gear switch.
2. Determines whether the switch or signal circuit is open. The circuit can be checked for an open by measuring the voltage (with a voltmeter) at the TCC connector. Should be about 12 volts.
3. Because the switch should be grounded in this step, disconnecting the TCC connector should cause the "SCAN" switch state to change.
4. The switch state should change when the vehicle shifts into 3rd gear.