Cutlass Ciera Cruiser V6-3100 3.1L MFI VIN M (1994)
Camshaft Position Sensor: Description and Operation
PURPOSE
The camshaft sensor is a hall-effect sensor installed on the top front of the engine, above the front of the camshaft. The tip of the sensor comes
very near a reluctor "pole" piece, cast as part of the camshaft. When this pole piece passes the sensor tip, the disturbance in the sensors magnetic
field turns the hall-effect switch "OFF" and "ON" again, producing a signal that the computer can read.
OPERATION
As the camshaft sprocket turns, a magnet in it activates the Hall-effect switch in the cam sensor. When the Hall-effect switch is activated, it
grounds the signal line to the Powertrain Control Module (PCM), pulling the cam signal line's applied voltage low. This is interpreted as a cam
signal. The cam signal is created as piston # 1 is on the intake stroke and used by the PCM to synchronize Sequential Fuel Injection (SFI) mode of
operation with each intake valve opening. If the cam signal is not received by the PCM, the PCM will still operate in the SFI mode based on the
reference signal, however, SFI mode timing may not be as accurate because the PCM does not know the exact time the intake valve is opening. A
loss of this signal or extra cam signals, above 500 RPM, to the PCM will set a Diagnostic Trouble Code (DTC) P0342 or P0341. See: Testing and
Inspection/Diagnostic Trouble Code Tests and Associated Procedures/P Code Charts/P0341
