P0320 No Crank Reference Signal at PCM

NAME OF CODE
No Crank Reference Signal at PCM

WHEN MONITORED
With the ignition in either the start or run position and battery voltage between 4-15 volts.

SET CONDITION
No crankshaft position sensor signal is detected when engine vacuum is present or cam signals are present.

THEORY OF OPERATION
The crankshaft position sensor is a hall-effect type sensor used to detect the crankshaft's speed and position. The PCM supplies 8 volts and a sensor ground to the CKP sensor. The crankshaft position sensor signal circuit has a 5-volt pull-up from the PCM. The sensor signal is created by the volts cut in the flywheel passing under the sensor. When a slot is under the sensor, the signal is high (5v). When the metal between the slots is under the sensor, the signal is low (0.3v).

POSSIBLE CAUSES
- Open or shorted 8-volt supply circuit
- Open sensor ground
- Open or shorted signal circuit
- Excessive clearance between the sensor and flywheel
- Damaged flywheel
- Failed sensor
- Failed PCM