GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The crankshaft position (CKP) sensor signal indicates the crankshaft speed and position. The CKP sensor is connected directly to the powertrain control module (PCM) and consists of the following circuits:

    • The 12-volt reference circuit
    • The low reference circuit
    • The CKP sensor signal circuit

Conditions for Running the DTC

The engine is cranking or running.

Conditions for Setting the DTC

The PCM determines that the CKP sensor signal is out of range for less than 2 seconds.

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 MIL/DTC

    • The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    • 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 emission related diagnostic.
    • Clear the MIL and the DTC with a scan tool.

Diagnostic Aids

Important: 

   • Remove any debris from the PCM module connector surfaces before servicing the PCM module. Inspect the PCM module connector gaskets when you diagnose or replace the modules. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM modules.
   • For any test that requires probing the PCM or probing a component harness connector, use the Connector Test Adapter Kit J 35616 . Using this kit prevents damage to the harness and the component terminals. Refer to Using Connector Test Adapters in Wiring Systems.

    • The following conditions may cause this DTC to set:
       - Poor connections--Refer to Testing for Intermittent Conditions and Poor Connections 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
       - If the crankshaft rotates backwards, this DTC sets. This condition only occurs with vehicles that are equipped with a manual transmission. This condition occurs when a vehicle is on an incline, and the clutch is released and an engine stall occurs.
    • 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 conditions:
       - A no start
       - A start and stall
       - Erratic performance
    • An improperly-installed propeller shaft could cause excess crankshaft end play.
    • For an intermittent condition condition, refer to Intermittent Conditions .

Test Description

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

  1. This step verifies that the malfunction is present.

  2. This step tests for electromagnetic interference (EMI) on the CKP sensor circuits.

  3. Vertical lines across the face of the sensor could indicate foreign material passing between the CKP sensor and the reluctor wheel. Non-vertical lines across the face of the sensor may indicate a crack in the CKP sensor. Either of these conditions cause this DTC to set.

  4. Damage to the reluctor wheel can affect the CKP sensor output. In order 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, you may need to remove the oil pan.

Step

Action

Yes

No

Schematic Reference: Engine Controls Schematics

1

Did you perform the Diagnostic System Check-Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

Important: If DTC P0335 is also set, diagnose DTC P0335 before proceeding with this DTC.

  1. Observe the Freeze Frame/Failure Records data for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the conditions for Running the DTC, as specified in the supporting text . Attempt to duplicate the Freeze Frame/Failure Records data that you observed.

Does the DTC fail this ignition?

Go to Step 3

Go to Diagnostic Aids

3

  1. Inspect all circuits going to the CKP sensor for incorrect harness routing:
  2. • Routing that is too close to the secondary ignition wires or components
    • Routing that is too close to any after-market add-on electrical equipment
    • Routing that is too close to the solenoids, the relays, and the motors
  3. If you find incorrect routing, correct the harness routing.

Did you find and correct the condition?

Go to Step 9

Go to Step 4

4

  1. Inspect for poor connections at the CKP sensor. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
  2. If you find a poor connection, repair the terminal as necessary. Refer to Repairing Connector Terminals in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 5

5

  1. Inspect for poor connections at the PCM for the CKP sensor circuits.
  2. If you find a poor connection, repair the terminal as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 6

6

  1. Remove the CKP sensor. Refer to Crankshaft Position Sensor Replacement .
  2. Inspect the CKP sensor for signs of damage.
  3. If the CKP is damaged, refer to Crankshaft Position Sensor Replacement .

Did you find and correct the condition?

Go to Step 9

Go to Step 7

7

  1. Inspect the CKP reluctor wheel for damage.
  2. If you find the CKP reluctor wheel damaged, refer to Camshaft and Bearings Cleaning and Inspection in Engine Mechanical-5.7L for crankshaft replacement.

Did you find and correct the condition?

Go to Step 9

Go to Step 8

8

Replace the CKP sensor. Refer to Crankshaft Position Sensor Replacement .

Did you find and correct the condition?

Go to Step 9

--

9

  1. Use the scan tool in order to clear the DTCs.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate vehicle within the Conditions for Running this DTC as specified in the supporting text.

Does the DTC run and pass?

Go to Step 10

Go to Step 2

10

With a scan tool, observe the stored information, Capture Info.

Does the scan tool display any DTCs that you have not diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK