Aspire L4-81 1.3L SOHC (1994)
Cylinder Identification Sensor: Description and Operation
CID/CKP Sensor
DESCRIPTION
The Cylinder Identification (CID) sensor detects Number 1 cylinder when it reaches Top Dead Center (TDC) and signals the Powertrain Control
Module (PCM) to control fuel injection.
OPERATION
A single vane rotor cap is mounted to the distributor shaft, below the crankshaft position rotor cap, where it spins according to the camshaft speed.
As it rotates through a magnetic Hall effect pickup switch, the sensor detects the opening on the rotor cap and sends an input signal to the PCM.