Circuit Description
The crankshaft position (CKP) sensor is a sensor designed to detect changes in a magnetic field. The control module supplies the CKP sensor a signal and ground circuits. Ignition voltage is supplied to the sensor by an independent circuit. The CKP sensor produces a magnetic field whenever the ignition is ON. The CKP sensor is mounted near a reluctor wheel that is attached to the crankshaft. When the crankshaft rotates, when the engine is cranking or running, the toothed reluctor wheel changes the magnetic field. The CKP sensor converts each change in the magnetic field into a PULSE. The number of teeth on the reluctor wheel determines how many pulses the CKP sensor detects per crankshaft rotation. The CKP sensor signal is used in order to determine the engine speed, the crankshaft position, and to detect misfire.
If a loss of the CKP signal or an erratic signal is detected by the VCM while the engine is running, this DTC will be set.
Conditions for Running the DTC
The MAF is 5 g/s or more.
Conditions for Setting the DTC
The VCM detects an instantaneous change in engine speed more than 1,000 RPM.
Action Taken When the DTC Sets
| • | The VCM illuminates the MIL during the second consecutive drive cycle in which the diagnostic reports a fail. |
| • | The VCM will set the DTC and records the operating conditions at the time the diagnostic fails. The VCM stores the failure information in the scan tools Freeze Frame and Failure Records. |
Conditions for Clearing the MIL or DTC
| • | The control module turns OFF the MIL after 3 consecutive drive trips when the test has run and passed. |
| • | A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles. A warm-up cycle occurs when the coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant reaches a temperature that is more than 70°C (158°F) during the same ignition cycle. |
| • | Use a scan tool in order to clear the DTCs. |
Diagnostic Aids
Inspect the face of the CKP sensor for metallic particles. This could result in an intermittent DTC.
Check for the following:
| • | A chipped or damaged reluctor wheel |
| • | Incorrect reluctor wheel |
| • | Incorrect alignment of the CKP sensor to reluctor wheel |
| • | Excessive crankshaft end play |
| • | Refer to Symptoms . |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This test checks the ignition positive voltage circuit to the crankshaft position sensor.
-
This test checks the duty cycle of the crankshaft position sensor.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 |
Important: Before clearing DTCs, use the scan tool Capture Info function to save the Freeze Frame and the Failure Records for reference. The control module's data is deleted once the Clear Info function is used. Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||
2 | Does the vehicle start and continue to run? | -- | Go to Diagnostic Aids | |
Is the test lamp ON? | -- | |||
4 | Connect the test lamp between the CKP sensor connector gnition positive voltage and ground terminals. Is the test lamp ON? | -- | ||
Is the duty cycle within the specified value? | 23 %-43 % | |||
6 | Repair the open or short to ground in the CKP sensor ignition positive voltage circuit. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | -- | |
7 | Check the CKP sensor ground circuit for an open. Did you find a problem? | -- | ||
8 | Check for an open or a short in the CKP sensor (4X) signal circuit. Did you find a problem? | -- | ||
9 | Check the crankshaft position (CKP) sensor and the crankshaft reluctor wheel for damage. Refer to Diagnostic Aids. Did you find a problem? | -- | ||
10 |
Is the action complete? | -- | -- | |
11 | Check for a poor connection at the CKP sensor. Did you find a problem? | -- | ||
12 |
Important: Inspect the CKP sensor mounting surface to ensure that the surface is clean and free of debris.
Refer to Crankshaft Position System Variation Learn . Is the action complete? | -- | -- | |
13 | Check for a poor connection at the VCM. Did you find a problem? | -- | ||
14 | Repair the circuit as necessary. Refer to Connector Repairs or Wiring Repairs in Wiring Systems. Is the action complete? | -- | -- | |
15 |
Refer to Crankshaft Position System Variation Learn . Is the action complete? | -- | -- | |
16 |
Does the scan tool indicate that the diagnostic Passed? | -- | ||
17 | Does the scan tool display any additional undiagnosed DTCs? | -- | Go to the applicable DTC table | System OK |
