The CKP sensor is a magnetic transducer mounted on the engine block adjacent to a pulse wheel located on the crankshaft. By monitoring the crankshaft mounted pulse wheel, the CKP is the primary sensor for ignition information to the PCM. The pulse wheel has a total of 35 teeth spaced 10 degrees apart with one empty space for a missing tooth. The 6.8L 10-cylinder pulse wheel has 39 teeth spaced 9 degrees apart and one 9 degree empty space for a missing tooth. By monitoring the pulse wheel, the CKP sensor signal indicates crankshaft position and speed information to the PCM. By monitoring the missing tooth, the CKP sensor is also able to identify piston travel in order to synchronize the ignition system and provide a way of tracking the angular position of the crankshaft relative to a fixed reference for the CKP sensor configuration. The PCM also uses the CKP signal to determine if a misfire has occurred by measuring rapid decelerations between teeth.
Removal & Installation
- With the vehicle in NEUTRAL, position it on a hoist.
- Disconnect the battery ground cable.
- Remove the two retaining screws and the crankshaft pulley shield.
- Disconnect the crankshaft position (CKP) sensor electrical connector.
Remove the engine plug bolt.
Turn the crankshaft pulley bolt to position the number one cylinder at top dead center, and install the special tool into the engine plug bolt bore.
- Remove the CKP sensor retaining bolts and the sensor.
- Install and hand-tighten a 6 mm x 18 mm standard bolt into the crankshaft damper to hold its position.
Install a new CKP sensor, but do not tighten the bolts at this time.
NOTEThe crankshaft position (CKP) sensor alignment tool is supplied with the new sensor and is not available separately.
Adjust the CKP sensor with the alignment tool and tighten the bolts.
- Connect the CKP sensor electrical connector.
- Remove the holding bolt from the crankshaft damper.
- Remove the special tool from the engine plug bolt bore.
- Install the engine plug bolt and tighten to 15 ft. lbs. (20 Nm).
- Install the crankshaft pulley shield.
- With the CKP sensor connector disconnected, the Key ON and the engine OFF, measure the voltage between the sensor pins on the harness side of the connector. Voltage should be between 1-3 volts.
With Key in OFF position, disconnect the CKP sensor connector and measure the resistance between the sensor pins. The CKP sensor resistance values change significantly with temperature rise. The resistance should be between 250-1000 ohms.