Neon L4-2.0L SOHC (1995)
Camshaft Position Sensor: Description and Operation
No Cam Signal at PCM
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 Powertrain Control Module (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 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