Neon L4-2.0L DOHC (1996)
Camshaft Position Sensor: Description and Operation
No Cam Signal at PCM Trouble Code
Name of Code:
No Cam Signal at PCM
When Monitored:
During engine cranking, after a number of crank position sensor signals have been detected.
Set Condition:
Signals are not received from the camshaft position sensor when signals are received from the crankshaft position sensor
Theory of Operation:
The camshaft position (CMP) sensor is a hall-effect type sensor used to detect the camshaft's position. The PCM supplies 8 volts and a sensor
ground to the CMP sensor. The camshaft position sensor signal circuit has a 5 volt pull-up from the PCM. The sensor signal is created by a
rotating target magnet attached to the rear of the camshaft when the north pole of the magnet passes under the sensor, the signal remains at 5 volts.
When the south pole passes under the sensor, the signal drops to 0.3 volt.
Possible Causes:
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Open or shorted 8-volt supply circuit
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Open sensor ground
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Open or shorted signal circuit
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Excessive clearance between the sensor and target magnet
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Damaged target magnet
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Failed sensor
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Failed PCM
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Broken timing belt
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Connector terminals
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Connector wires
