The Crankshaft Position (CKP) sensor system consists of a CKP sensor plate and a pickup coil. The sensor plate has 34 teeth and is installed on the crankshaft. The pickup coil is made of an iron core and a magnet.

The sensor plate rotates and, as each tooth passes through the pickup coil, a pulse signal is created. The pickup coil generates 34 signals per engine revolution. Based on these signals, the ECM calculates the crankshaft position and engine RPM. Using these calculations, the fuel injection time and ignition timing are controlled.


DTC Detection Conditions

Trouble Areas


• No Crankshaft Position (CKP) sensor signal to ECM while cranking (1 trip detection logic)

• No CKP sensor signal to ECM at engine speed of 600 rpm or more (1 trip detection logic)

• Open or short in CKP sensor circuit

• Sensor plate (CKP sensor plate)



Under conditions (a), (b) and (c), no Crankshaft Position (CKP) sensor signal to ECM for 0.05 seconds or more (1 trip detection logic):

(a) Engine speed 1,000 rpm or more

(b) Starter signal OFF

(c) 3 seconds or more have elapsed since starter signal switched from ON to OFF

• Open or short in CKP sensor circuit

• Sensor plate (CKP sensor plate)

i i i i V-V

i i i i ^wv-




Reference: Inspection using an oscilloscope HINT:

• The correct waveform is shown on the left.

• G2 stands for the Camshaft Position (CMP) sensor signal, and NE+ stands for the CKP sensor signal.




CH1: G2 - NE-CH2: NE+ - NE-

Equipment Settings

5 V/Division, 20 ms/Division


Cranking or idling

Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

Don't pay hundreds of dollars to find out what is wrong with your car. This book is dedicated to helping the do it yourself home and independent technician understand and use OBD-II technology to diagnose and repair their own vehicles.

Get My Free Ebook

Post a comment