Camshaft Hall Sensor, Function

Camshaft Hall Sensor, Function




B6/1 Camshaft Hall sensor
B6/2 Camshaft Hall sensor, left cylinder bank (engine 120)
B6/3 Camshaft Hall sensor, right cylinder bank (engine 120)
f Ignition TDC cylinder 1 (and cylinder 7 with engine 120)
g Segment at exhaust camshaft sprocket
h Square-wave signal
x Wiring diagram illustration of the Hall sensor Camshaft

The signal cable of the camshaft Hall sensor has a voltage signal of approx. 12 V ("high"). If, however, the segment (a) at the camshaft sprocket (1) is just moving past the camshaft Hall sensor at that moment, the signal jumps to 0 V ("low").
This "0 V signal" is used for detecting ignition TDC of cylinder 1 (engine 120: second camshaft Hall sensor for additionally detecting ignition TDC of cylinder 7, left cylinder bank)




Shown on engine 120
1 Exhaust camshaft sprocket
a Camshaft sprocket segment (engine 104, 111, 119 segment at camshaft adjuster, Engines 112, 113 segment at the exhaust camshaft sprocket, on the right-hand cylinder bank)

The distance between the Hall sensor on the camshaft and the segment of the camshaft sprocket of the exhaust camshaft or the segment at the camshaft adjuster is not adjustable

Note: If no signal is received from the camshaft Hall sensor, the engine control unit determines the ignition TDC of cylinder 1 at random. The engines start about 1 second later and the emission levels at start are not optimal.
Engine 119 starts only if the ignition TDC of cylinder 1 has been correctly determined by chance. Engine may possibly start only at further attempt.