Camshaft and Crankshaft Sensor Description

***THIS ARTICLE INCLUDES UPDATES MADE BY TSB #89-5A-13, DATED MARCH 1989***

Hall Effect Device:

Rotary Vane Cup-CMP Sensor:

Figure 7 - Magnetic Flux Field:

Hall Effect Device Response To Vane:

Camshaft and Crankshaft Sensor Description


The Camshaft and Crankshaft Sensors are digital Hall devices (Figure 5). The Camshaft Sensor is in the location normally used for the distributor. A rotary vane cup (or wheel), made of ferrous metal (Figure 6), is used to trigger the Hall effect switch located in the sensor. The camshaft cup has one tooth and is driven by the camshaft. The signal from the camshaft sensor has one positive-going edge once every two crank revolutions (one cam revolution). The crankshaft cup has three teeth and the Crankshaft sensor generates three positive (PIP) edges every revolution of the crankshaft.

When the window of the vane cup is between the magnet and Hall effect device, a magnetic flux field is completed from the magnet through the Hall effect device and back to the magnet (Figure 7), the output signal will be low (0 volts). However, when the vane tooth moves into the gap between the Hall effect device and the magnet, the flux lines are shunted through the vane and back to the magnet (Figure 8) and the output will change from a low to high (VBAT).