Lumina V6-191 3.1L VIN T MFI (1993)
Camshaft Position Sensor: Description and Operation
Camshaft Position Signal
Camshaft Sensor
PURPOSE
The ECM uses the camshaft signal (CKT 633) to calculate true Sequential Fuel Injection (SFI) mode or operation.
OPERATION
As the camshaft sprocket turns, a permanent magnet activates the Hall-Effect switch in the cam shaft sensor. When the Hall-effect switch is
activated, it grounds the signal line to the ECM, pulling the camshaft signal line's applied voltage low. This is interpreted as a cam shaft signal.
LOCATION
The camshaft sensor is located on the timing cover behind the water pump near the camshaft sprocket.
DIAGNOSTIC NOTES:
When the cam shaft signal is not received by the ECM, a Code 41 will set. If the camshaft position signal is lost while the engine is running, the
fuel injection system will shift to a calculated sequential fuel injection mode based on the last cam pulse, and the engine will continue to run. The
engine can be restarted and will run in the calculated sequential mode as long as the fault is present with a 1 to 6 chance of being correct.
