Crankshaft Position Sensor: Description and Operation

Dual Hall Sensor:

PURPOSE
The Crankshaft Position (CKP) sensor is a dual Hall effect sensor. The dual effect sensor contains:

- the Profile Ignition Pickup (PIP) sensor; determines crankshaft speed and position.

- and the Cylinder Identification (CID) sensor; determines the position of the camshaft.

CONSTRUCTION
The CKP sensor is a passive electro-magnetic device. The dual Hall effect sensor includes:

- two Hall effect devices with an integrated circuit

- one permanent magnet

- a rotating vane cup that incorporates two vane cups as part of the crankshaft pulley hub assembly.

OPERATION
The CKP shares one permanent magnet. The sensor is mounted so the PIP cup on crankshaft damper rotates around the outside edge of the magnet. The CID rotates around the inside edge of the magnet.

CID and PIP Signal Comparison:

The PIP vane generates two PIP signals per crankshaft revolution. Base timing is 10 degrees BTDC, therefore a vane cup is aligned so the leading edge of a PIP signal occurs 10 degrees before the pistons reach TDC. The signal is ON for 90 degrees of crankshaft rotation. The signal is then OFF for 90 degrees of crankshaft revolution. This is a 50% duty cycle that results in a digital square wave.

The CID has one vane and generates one CID signal per crankshaft revolution. The vane cup is aligned so the leading edge of the CID signal occurs 10 degrees after the piston reaches TDC. The signal is ON for 180 degrees of crankshaft revolution. The CID signal is OFF for the remaining 180 degrees of crankshaft revolution.

NOTE: The Distributorless Ignition System (DIS) completes one ignition cycle for each revolution of the crankshaft. However, it takes two revolutions of the crankshaft to fire every cylinder and complete the four strokes of an engine cycle.