Venture V6-3.4L VIN E (1997)
Crankshaft Position Sensor: Description and Operation
24X and 7X (CKP) Sensor/Harmonic Balancer Interrupter Ring
24X Crankshaft Position (CKP) Sensor
7X Crank Shaft Position (CKP) Sensor
The 24X crankshaft position sensor (1), secured in an aluminum mounting bracket (3) and bolted to the front side of the engine timing chain cover (2),
is partially behind the crankshaft balancer (refer to the 24X Crankshaft Position Sensor graphic). The 7x crankshaft position sensor uses a two wire
connector at the sensor and a three-way connector at the ignition control module. The 24X crankshaft position sensor contains a Hall-effect switch.
The magnet and Hall-effect switch are separated by an air gap. A Hall-effect switch reacts like a solid state switch, grounding a low current signal
voltage when a magnetic field is present. When the magnetic field is shielded from the switch by a piece of steel placed in the air gap between the
magnet and the switch, the signal voltage is not grounded. If the piece of steel (called an interrupter) is repeatedly moved in and out of the air gap, the
signal voltage will appear to go On-Off-On-Off-On-Off. Compared to a conventional mechanical distributor, this On-Off signal is similar to the signal
that a set of breaker points in the distributor would generate as the distributor shaft turned and the points opened and closed.
In the case of the electronic ignition system, the piece of steel is a concentric interrupter ring mounted to the rear of the crankshaft balancer. The
interrupter ring has blades and windows that, with crankshaft rotation, either block the magnetic field or allow it to reach the Hall-effect switch. The
Hall-effect switch is called a 24X crankshaft position sensor, because the interrupter ring has 24 evenly spaced blades and windows. The 24X
crankshaft position sensor produces 24 On-Off pulses per crankshaft revolution.
The 7X crankshaft position sensor is the other Hall-effect switch closer to the crankshaft. The interrupter ring is a special wheel cast on the crankshaft
that has seven machined slots, six of which are equally spaced 60 degrees apart. The seventh slot is spaced 10 degrees from one of the other slots. as
the interrupter ring rotates with the crankshaft, the slots change the magnetic field. this will cause the 7X the Hall-effect switch to ground the 3X signal
voltage that is supplied by the ignition control module. The ignition control module interprets the 7X On-Off signals as an indication of crankshaft
position. The ignition control module must have the 7X signal to fire the correct ignition coil. The 24X interrupter ring and Hall-effect switch react
similarly. The 24X signal is used for better resolution at a calibrated RPM.
