The Crankshaft Position (CKP) Sensor is a permanent magnet output coil device that monitors the speed and position of the crankshaft. A reluctor is attached directly to the crankshaft, and is used to generate a constant signal as it passes the CKP sensor magnetic coil. The CKP Sensor utilizes system voltage (12 volts DC), or reference voltage (5 volts DC) to generate a digital output signal to the PCM that is based upon a 0.5 volt AC reference. The alternating magnetic field is used by the sensor output electronics to produce a digital pulse. The CKP sensor returns a digital ON/OFF signal pulse during each revolution of the crankshaft, with a momentary signal interrupt for the top dead center (TDC) position of the #1 cylinder. The Pulse Width Modulation pattern is used by the Powertrain Control Module (PCM) to calculate ignition timing, fuel injector timing, misfire diagnostics, and the tachometer display.
CKP Circuit Testing
Use a suitable scan tool or a Graphing Multi-Meter (GMM in order to view the CKP data.
CKP Sensor logic is based on alternating lines of magnetic flux which generate a digital ON/OFF signal to the PCM, and are based on the speed and position of the crankshaft.
Verify that the engine timing components (timing belt, timing chain, or timing gears) are properly installed, and that there is no foreign material obstructing the path between the reluctor and the CKP sensor. If any engine mechanical faults are evident, locate and repair as required before continuing.
A Digital Volt-Ohm Meter (DVOM) may be used to verify the condition of the wiring: additional information may be acquired by taking measurements at the sensor connector as well as the PCM connector. If significant resistance is measured (greater than 5 ohms), check the wiring harness and connections for corrosion, poor pin connections, or damaged wires.
If all engine wiring and pin connections are confirmed, disconnect the CKP Sensor to verify the signal with a GMM, and verify PCM communication before replacing the CKP Sensor.
The CKP Sensor provides a digital input signal to the Powertrain Control Module (PCM) for a number of engine control system calculations. The CKP signal is compared with the Camshaft Position Sensor (CMP) and Vehicle Speed Sensor (VSS) for measured operating conditions, and the Pulse Width Modulation pattern is used by the Powertrain Control Module (PCM) to calculate ignition timing, fuel injector timing, misfire diagnostics, and the tachometer display.Connection & Wiring Diagnosis
Refer to the Electrical Wiring Diagram for component and connector locations, connector views, and circuit-specific information.
Many intermittent open or short circuits may be caused by wiring harness and connector movement due to vibration, engine torque, bumps and rough pavement, etc.
Test the wiring harness and connectors by performing the following tests:
Move the related connectors and wiring while monitoring the appropriate scan tool data.
Test the connector terminal pins and/or wiring by performing the following tests:
Inspect for incorrect mating of the connector halves, or terminals not fully seated in the connector body.