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 the frequency of the CKP is less than expected by the VCM, this DTC will be set.
Conditions for Running the DTC
| • | The engine speed is less than 4,000 RPM |
| • | The MAF sensor is 5 g/s or greater |
Conditions for Setting the DTC
The crankshaft position sensor duty cycle is less than a calibrated percent.
Action Taken When the DTC Sets
The VCM stores the DTC in History if the VCM detects an intermittent problem.
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
A poor connection, rubbed through wire insulation, or a wire that is broken inside the insulation may cause an intermittent problem.
Thoroughly check any circuitry, that is suspected of causing the intermittent complaint for the following conditions:
| • | Backed out terminals |
| • | Improper mating |
| • | Broken locks |
| • | Improperly formed or damaged terminals |
| • | Poor terminal to wire connections |
| • | Physical damage to the wiring harness |
Inspect the face of the CKP sensor for metal shavings. This could result in an intermittent DTC P0339.
Refer to Symptoms .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step checks the ignition feed circuit to the Crankshaft Position sensor.
-
This step determines if the circuit is shorted to ground.
-
This test checks the crank sensor for duty cycle output.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 |
Important: Before clearing the DTCs, use the scan tool in order to record the Freeze Frame and the Failure Records for reference. This data will be lost when the Clear DTC Information function is used. Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||
Is the lamp ON? | -- | |||
3 |
Is the lamp ON? | -- | ||
Is the test lamp ON? | -- | |||
5 | Check for a faulty connections at the CKP sensor. Was a problem found? | -- | ||
Is the duty cycle less than the specified value? | 23% | |||
7 | Check for an open in the CKP sensor ground circuit. Was a problem found? | -- | ||
8 | Check for an open or a short to a ground in the CKP sensor feed circuit. Was a problem found? | -- | -- | |
9 | Check for a faulty connection at the VCM. Was a problem found? | -- | ||
10 | Repair short to ground in Crankshaft Position sensor 4X signal circuit. Refer to Wiring Repairs in Repair Instructions. Is the repair complete? | -- | -- | |
11 |
Important: Inspect the CKP sensor mounting surface to insure the surface is clean and free of debris.
Is the action complete? | -- | -- | |
12 | Repair the circuit as necessary. Refer to Wiring Repairs in Repair Instructions. Is the action complete? | -- | -- | |
13 |
Is the action complete? | -- | -- | |
14 |
Does the scan tool indicate that this diagnostic ran and passed? | -- | ||
15 | Use the scan tool in order to display the Capture Info and the Review Capture Info functions. Are there any DTCs displayed that have not been diagnosed? | -- | Go to The Applicable DTC Table | System OK |
