Operation CHARM: Car repair manuals for everyone.

P0340 No Cam Signal at PCM

NAME OF CODE
No Cam Signal at 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 powertrain control module provides the sensor with a 8-volt source, 5-volt pull-up, and a sensor ground. 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