Test 12 - Controller Signal Testing

POWER TRANSISTOR SIGNAL CHECK





1. Check the input signal to the power transistor from Multi-Point Injection (MPI) controller by connecting a high impedance analog voltmeter to the middle (+) terminal of the power transistor connector and a good ground (-).
2. Crank the engine and watch the voltmeter for a fluctuating voltage signal.
3. If there is no voltage signal, check for an open or short in the wiring between the MPI controller and the power transistor.
4. If a wiring problem is found, repair and retest.
5. If there is a good signal and the engine will still not run, check engine mechanical and fuel systems for problems, the ignition system is functioning properly.
6. If there is no wiring problem, check computerized engine controls.