TCC Check - 200-R4 Transmission
ECM output to the transmission for TCC engagement occurs when: VSS signal is more than a given speed, MVS signal is more than a given throttle opening and governor switch is closed.
- This test checks for 12 volts at transmission TCC connector. Test light should not be "ON." If the light was "ON," there is either a short to 12 volts or a faulty ECM.
- This test checks for TCC engagement signal to transmission. Light should be "ON" above TCC engagement speed.
- This test checks for TCC engagement signal at ECM. Results will indicate an open or faulty ECM. If light flashes, ECM is trying to engage TCC but is shorted in wire or solenoid. The ECM has a short protection circuit that will protect TCC engage signal by cutting TCC signal "OFF" when short is detected.