RAM 3500 Truck 2WD L6-5.9L DSL Turbo VIN C (2003)
Camshaft Position Sensor: Description and Operation
CAMSHAFT POSITION SENSOR
The Camshaft Position Sensor (CMP) on this engine is located below the fuel injection pump. It is bolted to the back of the timing gear cover.
The Camshaft Position Sensor (CMP) contains a hall effect device. A rotating target wheel (tonewheel) for the CMP is located on the front timing
gear. This hall effect device detects notches located on the tone-wheel. As the tonewheel rotates, the notches pass the tip of the CMP
When the leading edge of the tonewheel notch passes the tip of the CMP, the following occurs: The interruption of magnetic field causes the voltage
to switch high resulting in a signal of approximately 5 volts.
When the trailing edge of the tonewheel notch passes the tip of the CMP, the following occurs: The change of the magnetic field causes the signal
voltage to switch low to 0 volts.
Fig.10 5.9L Diesel CMP
The CMP provides a signal to the Engine Control Module (ECM) at all times when the engine is running. The ECM uses the CMP information
primarily on engine start-up. Once the engine is running, the ECM uses the CMP as a backup sensor for engine speed. The Crankshaft Position Sensor
(CKP) is the primary engine speed indicator for the engine after the engine is running.
