Circuit Description
The Crankshaft Position Sensor (CKP) is mounted in front of the engine block under the timing chain cover. The CKP sensor works in conjunction with a 24X reluctor wheel mounted on the front of the crankshaft. The CKP sensor has a B+ power supply, a ground, and a signal circuit.
As the crankshaft rotates, the reluctor wheel teeth interrupt a magnetic field produced by a magnet within the sensor. The sensor's internal circuitry detects this and produces a signal which the PCM reads. The PCM uses this signal to accurately measure crankshaft velocity which is a variable used for spark and fueling.
The PCM also monitors the CKP sensor signal circuit for malfunctions. When the PCM detects a CKP sensor that is out of normal operating range, the PCM will set this DTC.
Conditions for Running the DTC
| • | DTCs P0102, P0103, P0341, P0342, P0343 are not set. |
| • | Camshaft Position sensor is transitioning. |
| • | MAF is greater than 3 g/s. |
| • | The ignition switch in the crank mode. |
Conditions for Setting the DTC
The PCM determines that no output from the CKP sensor signal for less than 3 seconds.
Action Taken When the DTC Sets
| • | The PCM will illuminate the malfunction indicator lamp (MIL) on the second consecutive drive trip that the diagnostic runs and fails. |
| • | The PCM will record operating conditions at the time the diagnostic fails. The first time the diagnostic fails, this information will be stored in Failure Records. If the diagnostic reports a failure on the second consecutive drive trip, the operating conditions at the time of failure will be written to Freeze Frame and the Failure record will be updated. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn the MIL OFF after 3 consecutive drive trips that the diagnostic runs and does not fail. |
| • | A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles (coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant temperature exceeds 70°C (160°F) during the same ignition cycle. |
| • | Use the scan tool Clear Information function. |
| • | Disconnect the PCM battery feed for 30 seconds. |
Diagnostic Aids
Important: Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing/replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM.
This DTC may not report a pass. The scan tool status for this DTC will never report a pass so it will appear that the diagnostic never runs. This will cause the MIL to remain ON until a DTC clear command or battery disconnect occurs.
The following problems may cause this DTC to set:
| • | Poor connections/terminal tension at the sensor. |
| • | Crankshaft reluctor wheel damage or improper installation. |
| • | The sensor coming in contact with the reluctor wheel. |
| • | The engine running out of fuel. |
Using Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data can aid in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also aid determining how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that you observed. This will isolate when the DTC failed. For an intermittent condition, refer to Symptoms .
Excess crankshaft end play will cause the CKP sensor reluctor wheel to move out of alignment with the CKP sensor. This could result in any one of the following:
| • | A no start |
| • | A start and stall |
| • | Erratic performance |
An improperly installed crankshaft could cause excess crankshaft end play.
For an intermittent, refer to Symptoms .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step determines if the fault is present.
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This step simulates a CKP sensor signal to the PCM. If the PCM receives the signal, the fuel pump will operate for about 2-3 seconds. If the fuel pump operates, the problem is either terminal contact at the CKP sensor, the CKP sensor or, the CKP sensor reluctor wheel.
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This test determines if the CKP sensor signal circuit or if the PCM is faulty.
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Damage to the reluctor wheel would affect the CKP sensor output. Inspect the reluctor wheel, by rotating the crankshaft while viewing the reluctor wheel through the CKP sensor hole. If you cannot determine if the reluctor wheel is damaged, the timing cover may have to be removed. Refer to Engine Front Cover Removal in Engine Mechanical.
-
Before replacing the PCM, check the PCM harness connections.
-
This DTC will not report a pass. The scan tool status for this DTC will never report a pass. The scan tool will only display when the diagnostic fails. The repair is not complete if the scan tool indicates that the diagnostic ran and failed.
Step | Action | Value(s) | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||||||||||
2 | Does the engine start and continue to run? | -- | ||||||||||
Does the scan tool indicate that this diagnostic failed this ignition? | -- | Go to Diagnostic Aids | ||||||||||
4 |
Caution: Before proceeding, remove the fuses for the ignition coil and fuel injector feed circuits in order to prevent personal injury from engine rotation, sparks, and excessive engine fueling.
Is the test lamp illuminated? | -- | ||||||||||
5 | Connect the test lamp between the CKP sensor ignition feed circuit and the CKP sensor ground circuit. Is the test lamp illuminated? | -- | ||||||||||
Momentarily connect the test lamp between the CKP sensor signal circuit and the CKP sensor ignition feed circuit. Does the fuel pump operate when ignition voltage was applied to the CKP sensor signal circuit? | -- | |||||||||||
Is the voltage within the specified range? | 4.0V - 6.0V | |||||||||||
8 | Check for an open or a short to ground in the CKP ignition feed circuit. Did you find and repair the condition? | -- | ||||||||||
9 | Check for an open or a poor connection in the CKP ground circuit. Did you find and repair the condition? | -- | ||||||||||
10 | Check the CKP sensor signal circuit for the following:
Refer to Wiring Repairs in Wiring Systems. Did you find and repair the condition? | -- | ||||||||||
11 | Remove the CKP sensor and visually inspect the CKP Sensor for the following conditions:
Did you find and correct the condition? | -- | ||||||||||
Visually inspect the CKP sensor reluctor wheel for damage. Did you find and correct the condition? | -- | |||||||||||
13 | Check for poor connections/terminal tension at the CKP sensor. Did you find and correct the condition? | -- | ||||||||||
14 | Replace the CKP Sensor. Refer to Crankshaft Position Sensor Replacement and Crankshaft Position Sensor Reluctor Ring Replacement . Is the action complete? | -- | -- | |||||||||
|
Important:: Program the new PCM. Replace the PCM. Refer to Powertrain Control Module Replacement . Is the action complete? | -- | -- | ||||||||||
Does the scan tool indicate that this test failed? | -- | |||||||||||
17 | Select the Capture Info option and the Review Info option using the scan tool. Are any DTCs displayed that you have not diagnosed? | -- | Go to the applicable DTC table | System OK |
