Circuit Functions

WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2004 Ford RV Cutaway, 2004 Ford Pickup, 2004 Ford F550 Super Duty, 2004 Ford F450 Super Duty, and 2004 Ford Excursion. However, it is still accessible from the selected car via links, so may be relevant.

The camshaft position (CMP) signal source is a magnetic pickup sensor mounted on the left front side of the engine block. The sensor reacts to a peg on a target wheel that is positioned on the camshaft. The peg will pass the sensor once per camshaft revolution and produce a single pulse correspondingly. Camshaft speed is calculated from the frequency of the CMP sensor signal. Diagnostic information on the CMP input signal is obtained by performing accuracy checks on signal levels, frequency and duty cycle with software strategies.

The powertrain control module (PCM) needs the crankshaft position (CKP) sensor and CMP signal to calculate engine speed and position. The CMP creates a signal that the engine control module (ECM) uses to indicate a particular bank. The CMP contains a permanent magnet that creates a magnetic field. The signal is created when the camshaft peg rotates past the sensor breaking the magnetic field. The engine will not operate without a CMP signal.