No Cam Signal at PCM

NO CAM SIGNAL AT POWERTRAIN CONTROL MODULE (PCM)

When Monitored
During engine cranking, after 32 crank position signals.

Set Condition
No signal from the cam position sensor is present with crank signal.

Theory of Operation
The cam position sensor is a hall effect-type sensor used to detect the camshaft position. The PCM supplies 8 volts from cavity 7 to power up the sensor. Sensor ground is provided by PCM cavity 4. The PCM also supplies a 5-volt pull-up voltage to the sensor, from cavity 44. The sensor signal is created by the slots cut in the camshaft sprocket 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 8-volt supply circuit.
- Open sensor ground.
- Open or shorted signal circuit.
- Excessive clearance between the sensor and sprocket
- Damaged sprocket.
- Failed sensor.
- Failed PCM.