California Spec. Vehicles

PURPOSE
The engine rpm signal is produced by the NE pickup coil, located in the distributor. The G1 and G2 pickup coils, also located in the distributor though separate, work in conjunction with the NE pickup coil and produces an output pulse to the ECM. The ECM uses this signal to determine engine speed and relative top dead center for each cylinder.

OPERATION
The NE coil detects the crankshaft angle and rotational speed and the G1 and G2 coils detect the camshaft angle. Whenever the engine is rotating, a pulsed signal is returned to the ECM. As engine speed increases the frequency of the signal increases as well. With the NE signal coupled with the signal of the G1 and G2 pickup coils, exact piston position can be determined by the ECM.