For 1990-2009 cars
Engine Controls Components
Engine Speed Output, CKP and CMP Sensors
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

### Circuit Description

The Crankshaft Position Sensor CKP is mounted in the right rear of the engine block behind the starter. The CKP sensor works in conjunction with a 24X reluctor wheel mounted on the rear 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 in order to detect misfire, spark and, fueling.

### Conditions for Running the DTC

• | DTCs P0101, P0102 , P0103, P0341, P0342, P0343 are not set.

• | The CMP sensor is transitioning.

• | The ignition voltage is between 5.0 and 17.0 volts.

• | The MAF is greater than 3 g/s.

• | The ignition switch in the crank mode.

### Conditions for Setting the DTC

The PCM determines no signal from the CKP sensor for less than 3 seconds.

### Action Taken When the DTC Sets

• | The PCM illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.

• | The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure Records.

### Conditions for Clearing the MIL/DTC

• | A last test failed, or the current DTC, clears when the diagnostic runs and does not fail.

• | A history DTC clears after 40 consecutive warm-up cycles, if failures are not reported by this or any other emission related diagnostic.

• | Use a scan tool in order to clear the MIL/DTC.

### 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.

• | For any test that requires probing the PCM or a component harness connector, use the Connector Test Adapter Kit J 35616 . Using this kit prevents damage to the harness connector terminals.

• | The following conditions may cause this DTC to set:

- | Poor connections/terminal tension at the sensor. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.

- | Crankshaft reluctor wheel damage or improper installation

- | The sensor coming in contact with the reluctor wheel

- | The engine running out of fuel.

• | 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 propeller shaft could cause excess crankshaft end play. Refer to Propeller Shaft Diagnosis in Engine Mechanical 5.7L.

• | 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, refer to Symptoms .

### Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. This step determines if the fault is present.

2. This step simulates a CKP sensor signal to the PCM. If the PCM receives the signal, the fuel pump will operate for about two seconds. If the fuel pump operates, the condition is either terminal contact at the CKP sensor, the CKP sensor or, the CKP sensor reluctor wheel.

3. This test determines if the CKP sensor signal circuit or if the PCM is faulty.

4. The CKP System Variation Learn Procedure must be performed anytime the relationship between the CKP sensor and the CKP reluctor wheel is changed.

5. To inspect the reluctor wheel, remove the starter and rotate the crankshaft while viewing the reluctor wheel through the CKP sensor hole. If you cannot determine if the reluctor wheel is damaged, the oil pan may have to be removed.

6. The CKP System Variation Learn Procedure must be performed anytime the relationship between the CKP sensor and the CKP reluctor wheel is changed.

7. Before replacing the PCM, inspect the PCM harness connections.

8. 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? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check
2 | Does the engine start and continue to run? | -- | Go to Step 3 | Go to Step 4
3 |

1. Turn ON the ignition leaving the engine OFF.
2. Review the Freeze Frame and/or Failure Records data for this DTC and record or document the parameters.
3. Turn OFF the ignition for 15 seconds.
4. Start the engine.
5. Operate the vehicle within the conditions required for this diagnostic to run, and as close to the conditions recorded in Freeze Frame/Failure Records as possible. Special operating conditions that you need to meet before the PCM will run this diagnostic , where applicable, are listed in Conditions for Running the DTC.
6. Select the Specific DTC option under the Diagnostic Trouble Code (DTC) option using a scan tool.

Does the scan tool indicate that this diagnostic failed this ignition?

--

Go to Step 4

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.

1. Turn ON the ignition leaving the engine OFF.
2. Lift the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
3. Disconnect the Crankshaft Position (CKP) sensor.
4. Measure the voltage from the CKP sensor ignition feed circuit using the DMM J 39200 connected to ground.

Does the DMM display the specified voltage?

B+

Go to Step 5

Go to Step 8

5 | Connect the DMM J 39200 between the CKP sensor ignition feed circuit and the CKP sensor ground circuit. Does the DMM display the specified voltage? | B+ | Go to Step 6 | Go to Step 9
6 | 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? | -- | Go to Step 11 | Go to Step 7
7 |

1. Connect the CKP sensor.
2. Disconnect the PCM connector C1 located on the opposite side of the manufacturer's logo. Refer to Powertrain Control Module Replacement/Programming
3. Probe the CKP sensor signal circuit using the DMM J 39200 set to the 40V AC scale.
4. Crank the engine.

Is the voltage within the specified range?

4.0-6.0V

Go to Step 15

Go to Step 10

8 |

1. Test for an open or a short to ground in the CKP ignition feed circuit.
2. If you find the CKP ignition feed circuit open or shorted to ground repair the condition as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and repair the condition?

--

Go to Step 16

Go to Step 15

9 |

1. Test for an open or a poor connection in the CKP ground circuit. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.
2. If you find the CKP ground circuit open or a poor connection, repair the condition as necessary. Refer to Wiring Repairs or Repairing Connector Terminals in Wiring Systems.

Did you find and repair the condition?

--

Go to Step 16

Go to Step 15

10 | Test the CKP sensor signal circuit for the following:

• | An open

• | A short to ground

• | A short to voltage

• | If you find a condition repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and repair the condition?

--

Go to Step 16

Go to Step 11

11 | Important: The CKP System Variation Learn Procedure must be performed anytime the relationship between the CKP sensor and the CKP reluctor wheel is changed.

1. Remove the CKP sensor and visually inspect the CKP Sensor for the following conditions:

• | Physical damage

• | Loose or improper installation

• | Wiring routed too closely to secondary ignition components

2. If you find a condition, repair as necessary.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 12

12 |

1. Inspect for poor connections/terminal tension at the CKP sensor. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.
2. If you find a poor connection repair the condition as necessary. Refer to Repairing Connector Terminals in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 13

13 | Visually inspect the CKP sensor reluctor wheel for damage. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 14
14 |

1. Replace the CKP Sensor. Refer to Crankshaft Position Sensor Replacement .
2. Perform the Crankshaft Position System Variation Learn .

Is the action complete?

--

Go to Step 16

--

15 | Important:: Program the replacement PCM. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Is the action complete? | -- | Go to Step 16 | --
16 |

1. Select the Diagnostic Trouble Codes (DTC) option and the Clear DTC Information option using the scan tool.
2. Idle the engine at the normal operating temperature.
3. Select the Specific DTC option under the Diagnostic Trouble Code (DTC) option using a scan tool.
4. Operate vehicle within the Conditions for Running the DTC as specified in the supporting text, if applicable.

Does the scan tool indicate that this test passed?

--

Go to Step 17

Go to Step 2

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