[old_master]

The pick up coil in the distributor generates AC voltage, (measured in millivolts), when the distributor turns. The AC voltage is sent through the ignition module to the PCM for processing. The PCM adjusts the ignition timing and sends a modified DC voltage signal to the ignition module. The ignition module sends a pulsed ground to the ignition coil and the ignition coil fires.

Battery voltage is applied to the injectors when the ignition is in the START or RUN positions. The PCM uses the data from the pick up coil to determine when to fire the injectors. The PCM applies a pulsed ground directly to the injectors which completes the circuit, and the injectors open.

4 terminal connector on the ignition module:

G = Ignition Control low voltage reference (from ignition module to PCM)
B = Timing bypass (from PCM to ignition module during closed loop operation)
R = Ignition Control high voltage reference (from ignition module to PCM)
E = Ignition Control (from PCM to ignition module during open loop operation)

The two terminal connector on the ignition module:

+ = Battery voltage when ignition is in RUN or START position
C = Supplies pulsed ground to ignition coil

To check the pick up coil:
1). Connect an ohmmeter to each terminal of the pick-up coil connector or wire and ground (one terminal at a time). The ohmmeter should indicate infinite resistance. If it doesn't, the pick-up coil is defective.

2). Connect the ohmmeter between both terminals or wires of the pick-up coil connector. The ohmmeter should indicate one steady value within the 500 to 1500 ohm range as the wires are flexed. If it doesn't, the pick-up coil is defective.

If the pick-up coil fails either test. replace it.



Hope this helps.