Circuit Description
The crankshaft position (CKP) sensor works in conjunction with a 58 tooth reluctor wheel on the crankshaft. The engine control module (ECM) monitors the voltage between the CKP sensor signal circuits. As each reluctor wheel tooth rotates past the sensor, the sensor creates an analog signal. This analog signal is processed by the ECM. The reluctor wheel teeth are 6 degrees apart. Having only 58 teeth leaves a 12 degree span that is uncut. This creates a signature pattern that enables the ECM to determine the crankshaft position. The ECM can determine which two cylinders are approaching the top center based on the CKP signal alone. The camshaft position (CMP) sensor signal is used in order to determine which of the two cylinders is on a firing stroke. The ECM can then properly synchronize the ignition system, the fuel injectors, and the knock control. This sensor is also used in order to detect misfire. Refer to DTC P0300 for information on misfire detection.
Conditions for Running the DTC
The ECM has detected CMP sensor pulses.
Conditions for Setting the DTC
The ECM has detected no CKP sensor pulses.
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. |
Conditions for Clearing the DTC
| • | A current DTC Last Test Failed clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic. |
| • | Clear the DTC with a scan tool. |
Diagnostic Aids
Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector. Using this kit prevents damage to the harness or component terminals. Refer to Using Connector Test Adapters in Wiring Systems. For an intermittent, refer to Symptoms - Engine Controls .
Check for the following conditions:
| • | The CKP shielded wiring for continuity or damage--By disconnecting the CKP sensor connector the shielded ground can be tested for continuity back to the ECM by connecting a test lamp to B+. Good CKP shield continuity will illuminate the test lamp. |
| • | Damaged harness--Inspect the wiring harness for any damage. If the harness appears to be OK, connect the DMM to the high and low signal inputs at the ECM connector. Monitor the resistance of the circuit while moving the harness in different locations. A fluctuation in the resistance will indicate the area of a possible concern. |
| • | Damaged CKP lead--If the sensor lead is damaged in any way the sensor must be replaced. |
| • | The CKP sensor for proper installation--A CKP sensor that is loose or not fully seated, causing an excessive air gap between the sensor and the reluctor wheel, may cause this DTC to set. |
If a repair is necessary refer to Wiring Repairs or Connector Repairs in Wiring Systems.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests for proper CKP sensor resistance.
-
This step tests the CKP circuits for a short to ground. The DMM should indicate OL.
-
This step determines if the cause of the incorrect resistance is the sensor or the circuits.
-
This step tests for a short to voltage.
-
This step tests for proper CKP A/C voltage output at engine cranking speed.
-
This step determines if the cause of the incorrect resistance is the sensor or the circuits.
Step | Action | Values | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |||||
2 | Attempt to start the engine. Does the engine start and run? | -- | Go to Diagnostic Aids | Go to Step 3 | ||||
Is the resistance within the specified range? | 774-946 ohms at 20°C (68°F) | Go to Step 4 | Go to Step 5 | |||||
Refer to the electrical schematic diagrams for a complete wiring view of the shielded ground. Is continuity indicated? | -- | Go to Step 8 | Go to Step 6 | |||||
Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 12 | |||||
Is voltage indicated? | -- | Go to Step 9 | Go to Step 7 | |||||
Is the voltage more than the specified value? | 2 V | Go to Step 13 | Go to Step 11 | |||||
Is continuity indicated? | -- | Go to Step 10 | Go to Step 11 | |||||
9 | Repair the short to voltage in the effected CKP circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 15 | -- | ||||
10 | Repair the short to ground in the affected CKP circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 15 | -- | ||||
11 | Test the CKP sensor for the following conditions:
Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 12 | ||||
12 | Replace the CKP sensor. Refer to Crankshaft Position Sensor Replacement . Did you complete the replacement? | -- | Go to Step 15 | -- | ||||
13 | Test for poor connections or poor terminal tension at the ECM connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 14 | ||||
14 |
Important:
Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the action? | -- | Go to Step 15 | -- | ||||
15 |
Does the DTC run and pass? | -- | Go to Step 16 | Go to Step 2 | ||||
16 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK | |||||
