- +12 VDC from battery;
- 5 V from the processor unit, interrupted when the distributor rotates.
1. Check the sensor on the car, for which disconnect the connector, turn on the ignition and check for the presence of 12 V between one of the terminals and ground (Do not connect sensor leads to ground).
2. Turn off the ignition.
3. Remove the distributor of ignition and attach a socket.
4. Carefully remove the wire insulation to connect the voltmeter.
5. Connect the voltmeter to ground, turn on the ignition and slowly turn the distributor shaft.
6. When the distributor is rotated by 1°, a voltage of 5 V should disappear and appear on one of the wires, and on the other wire this voltage should disappear and appear when the distributor is rotated 120°.
7. Check the condition of the rotor plate.