The Camshaft Position (CMP) Sensor on these engines is actually a Hall-effect type sensor, which is located in the distributor. This sensor provides a signal to the ECM regarding the position of the crankshaft.
On the 2.0L 9A engines the Hall-effect sensor in the distributor is used as the speed and reference sensor by the control module. The inductive pick up around the No. 4 spark plug wire serves as the reference sensor for cylinder identification for the control module.
On the 2.0L ABA engines the Hall-effect sensor in the distributor is used as the cylinder position reference sensor by the control module. On these engines, the Crankshaft Position (CKP) sensor is used to calculate engine speed.
The Camshaft Position (CMP) Sensor is an essential input for the ECM to determine ignition timing. For additional information, please refer to the following topic(s): Electronic Engine Controls, Camshaft Position Sensor