GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    •  Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC P0335: Crankshaft Position (CKP) Sensor Circuit

DTC P0336: Crankshaft Position (CKP) Sensor Performance

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

5-Volt Reference

P0335

P0335

--

--

CKP Sensor Signal

P0335

P0335

P0335

P0336

Low Reference

--

P0335

P0335

--

Circuit/System Description

The crankshaft position (CKP) sensor circuits consist of an engine control module (ECM) supplied 5-volt reference circuit, low reference circuit, and an output signal circuit. The CKP sensor is an externally magnetic biased digital output integrated circuit sensing device. The sensor provides a pulse for each magnetic pole of the magnetic encoder wheel on the crankshaft. Each pole on the encoder wheel is spaced at 60-pole spacing, with 2 missing poles for the reference gap. The CKP sensor produces an ON/OFF DC voltage of varying frequency, with 58 output pulses per crankshaft revolution. The frequency of the CKP sensor output depends on the velocity of the crankshaft. The CKP sensor sends a digital signal, which represents an image of the crankshaft encoder wheel, to the ECM as each pole on the wheel rotates past the CKP sensor. The ECM uses each CKP signal pulse to determine crankshaft speed and decodes the crankshaft encoder wheel reference gap to identify crankshaft position. This information is then used to determine the optimum ignition and injection points of the engine. The ECM also uses CKP sensor output information to determine the camshaft relative position to the crankshaft, to control camshaft phasing, and to detect cylinder misfire.

Conditions for Running the DTC

P0335

    • The ignition is ON.
    • The engine is running.
    • The DTC runs continuously when the above conditions are met.

P0336

    • DTCs P0016, P0201-P0204, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0335, P0340, P0341, P0365, P0366, P0443, P0453, or P0458 are not set.
    • The ignition is ON.
    • The engine is running.
    • The DTC runs continuously when the above conditions are met.

Conditions for Setting the DTC

P0335

The ECM does not detect a signal from the CKP sensor for 4 engine revolutions.

P0336

    • The ECM detects an incorrect number of CKP sensor pulses for 20 engine revolutions.
        OR
    • The ECM determines that the CKP sensor signal is out of range for 24 engine revolutions.

Action Taken When the DTC Sets

DTCs P0335 and P0336 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P0335 and P0336 are Type B DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Electronic Ignition (EI) System Description

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Attempt to start the engine. Observe the DTC information with a scan tool. DTCs P0335 and P0336 should not set.
  2. Move related harnesses/connectors of the CKP sensor. Verify the engine does not stumble, stall, or change engine speed.
  3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the CKP sensor.
  2. Ignition OFF, test for less than 1 ohm between the low reference circuit terminal 2 and ground.
  3. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  4. Ignition ON, engine OFF, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 and ground.
  5. If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
    If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  6. Ignition ON, engine OFF, test for 4.8-5.2 volts between the signal circuit terminal 1 and ground.
  7. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
    If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  8. Ignition OFF, connect a fused jumper wire to signal circuit terminal 1.
  9. Ignition ON, momentarily touch the other end of the fused jumper wire to the battery negative post repeatedly. The fuel pump relay parameter on the scan tool should change.
  10. If the fuel pump relay parameter changes, test or replace the CKP sensor.
    If the fuel pump relay parameter does not change, replace the ECM.
  11. Ignition OFF, inspect the CKP sensor for correct installation. Remove the CKP sensor from the engine. Inspect the sensor for damage.
  12. If the sensor is loose, inspect the sensor and the sensor bracket for damage. Replace as necessary.
  13. Inspect the engine for the following conditions:
  14.    Notice: Do not allow the crankshaft encoder wheel to come into contact with external magnetic fields or sharp metal objects. Do not drop the crankshaft encoder wheel. Do not damage the rubberized encoder track. Failure to follow these precautions may cause damage to the component.

    • Crankshaft encoder wheel for damage or debris
    • Timing belt, tensioner, and sprockets for wear or damage
  15. If all circuits and components test normal, test or replace the CKP sensor.

Component Testing

Important: You must perform the Circuit/System Testing before proceeding with Component Testing.

  1. Remove the CKP sensor and inspect the sensor for damage.
  2. Connect the connector to the CKP sensor.
  3. Ignition ON, engine OFF, observe the fuel pump relay parameter while passing a magnet by the tip of the sensor repeatedly. The fuel pump relay parameter should change.
  4. If the fuel pump relay parameter does not change, replace the CKP sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Crankshaft Position Sensor Replacement
    •  Crankshaft Rear Oil Seal Replacement for the crankshaft encoder wheel
    •  Control Module References for replacement, setup, and programming