Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

The crankshaft position (CKP) sensor circuits consist of an engine control module (ECM) supplied 5-volt reference circuit, low reference circuit and an output signal circuit. The CKP sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes of the teeth and slots of a 58-tooth reluctor wheel on the crankshaft. Each tooth on the reluctor wheel is spaced at 60-tooth spacing, with 2 missing teeth for the reference gap. The CKP sensor produces an ON/OFF DC voltage of varying frequency, with 58 output pulses per crankshaft revolution. The frequency of the CKP sensor output depends on the velocity of the crankshaft. The CKP sensor sends a digital signal, which represents an image of the crankshaft reluctor wheel, to the ECM as each tooth on the wheel rotates past the CKP sensor. The ECM uses each CKP signal pulse to determine crankshaft speed and decodes the crankshaft reluctor wheel reference gap to identify crankshaft position. This information is then used to determine the optimum ignition and injection points of the engine. The ECM also uses CKP sensor output information to determine the camshaft relative position to the crankshaft, to control camshaft phasing, and to detect cylinder misfire.

Inspect the CKP sensor connector and the ECM connector for corrosion.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

1. With the engine running, observe the Engine Speed parameter with the scan tool. The parameter should display the current engine speed matching the CMP Sensor parameter.

⇒	If the Engine Speed parameter displays a value other than the current engine speed, continue with Circuit/System Testing.

2. With the engine running, observe the CKP Active Counter parameter with the scan tool. The counter should increment from 0-255 and over again with each CKP sensor pulse.

⇒	If the CKP Active Counter displays a value of 0, or a fixed value, continue with Circuit/System Testing.

3. Turn OFF the ignition for 60 seconds.
4. Start the engine. Do not cycle the ignition until this test is completed.
5. Operate the vehicle in various operating conditions within the Conditions for Running the DTC and observe the CKP Resync Counter parameter with the scan tool. The CKP Resync Counter should remain at 0 counts.

⇒	If the CKP Resync Counter increments, continue with Circuit/System Testing.

1. With the ignition OFF, Inspect the engine wiring harnesses carrying the CKP sensor circuits for the following conditions:

•	Close routing of secondary ignition wires

•	Close routing of aftermarket electrical equipment

•	Close to solenoids, motors, and relays

⇒	Correct any wire harness routing or component placement conditions, if it is determined to be a possible source of electrical interference.

2. Disconnect the CKP sensor connector.
3. With the ignition ON and the engine OFF, measure for 4.8-5.2 volts at the connector between the 5-volt reference circuit of the CKP sensor and a good ground.

⇒	If the voltage is less than 4.8 volts, test for an open in the 5-volt reference circuit between the ECM and the CKP sensor connector. If the circuit tests normal, replace the control module.

4. With the ignition ON and the engine OFF, measure for 4.8-5.2 volts at the connector between the CKP sensor signal circuit and a good ground.

⇒	If the voltage is less than 4.8 volts, test for an open or a short to ground in the CKP sensor signal circuit between the ECM and the CKP sensor connector. If the circuit tests normal, replace the control module.

⇒	If the voltage is more than 5.2 volts, test for a short to voltage in the CKP sensor signal circuit between the ECM and the CKP sensor connector. If the circuit tests normal, replace the control module.

5. With the ignition ON and the engine OFF, measure for 1-3 mA at the connector between the CKP sensor signal circuit and a good ground.

⇒	If the amperage is more than 3 mA, test the CKP sensor signal circuit for a short to the 5-volt reference circuit between the ECM and the CKP sensor connector. If the circuit tests normal, replace the control module.

6. Connect a fused jumper wire to a good ground.
7. With the ignition ON and the engine OFF, observe the CKP Active Counter parameter on the scan tool.
8. Touch the jumper wire to the CKP sensor signal circuit repeatedly at the connector. The CKP Active Counter parameter should increment.

⇒	If the CKP Active Counter parameter does not increment, replace the ECM.

9. With the ignition ON and the engine OFF, measure for B+ at the connector between the low reference circuit of the CKP sensor and the battery positive post.

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If the voltage measured between the low reference circuit and the battery positive post is not the same as voltage measured between a good ground and the battery positive post, test for an open/high resistance in the low reference circuit between the ECM and the CKP sensor connector. If the circuit tests normal, replace the control module.

10. With the ignition OFF, inspect the CKP sensor for looseness. Remove the CKP sensor from the engine, inspect the sensor and the O-ring for damage.

⇒	Repair or replace the CKP sensor, if necessary.

11. Reconnect the connector to the CKP sensor.
12. Turn ON the ignition, with the engine OFF.
13. While observing the CKP Active Counter parameter on the scan tool, pass a steel object by the tip of the sensor repeatedly. The CKP Active Counter parameter should increment.

⇒	If the parameter remains at 0 or another fixed value, replace the CKP sensor.

14. With the ignition OFF, remove the oil pan. Refer to Oil Pan Replacement and inspect the engine oil for debris and the crankshaft reluctor wheel for damage or debris stuck in the teeth.

⇒	If debris is found in the engine oil, inspect the engine components to determine the cause.

⇒	If the crankshaft reluctor wheel is damaged, replace the crankshaft.

15. With the ignition OFF, remove the engine front cover. Refer to Engine Oil Pressure Sensor and/or Switch Replacement and inspect the timing chain, tensioner, and sprockets for wear or damage.

⇒	If any parts are worn or damaged, replace as necessary.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.