Genuine Volvo 960 Crankshaft Position Sensor

Volvo 960 Crankshaft Position Sensor Parts and Q&A

• Crankshaft Position Sensor
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  Q: What is the significance of the Crankshaft Position Sensor in engine operation on Volvo 960?

  A:

  The Crankshaft Position (CKP) Sensor. Aka, RPM or Impulse Sensor, the Crankshaft position sensor is necessary to determine the engine's speed and Top Dead Center (TDC) to ensure the precise timing of the ignition system. Positioned at the back of the engine block above the flywheel, this transmits the engine speed to the fuel control unit, which is very important for engine start-up. In case of vehicles with LH Jetronic and EZK Ignition Systems, the pulsewheel displays 60 markings for CKP sensor and 58 drilled holes provide information to the ignition control unit and 2 markings at 90 degrees Before Top Dead Center (BTDC) for cylinders No. 1 and 4 for control ignition timing without changing their timing. Similarly, Regina Engine Control and REX-1 Ignition Systems have 44 markings, the same thing for the ignition timing configuration. In Motronic Engine Control Systems the flywheel has holes on the top surface that induce voltage in the CKP sensor which generates an A/C signal with a frequency depending upon the number of holes passing per second; the voltage varies from 0.1 to 55 volt DC depending upon engine speed and temperature; a longer hole is provided at 90 TDC for cylinder 1 to allow the ECM to calculate camshaft position. For testing, unhook the negative battery cable, unhook the sensor connector and test the resistance across the two sensor terminals, it should be between 200-500 ohms, if not it is out of range, the sensor needs replacement. For removal and installation, remove the negative battery cable, access the sensor by removing the required components, unplug the connector and remove the retaining screws to remove the sensor. To install, install the sensor, tighten the bolts, reconnect the connector, reinsert any parts removed, and reconnect the negative battery cable.