GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Powertrain On Board Diagnostic (OBD) System Check 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 Circuit Performance

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

5-Volt Reference Circuit

--

P0335

P0335

P0336

CKP Sensor Signal

P0335

P0335

--

P0336

Low Reference

--

P0335

--

P0336

Circuit/System Description

The crankshaft position (CKP) sensor signal indicates the crankshaft speed and position. The CKP sensor produces an AC voltage of different amplitude and frequency. The frequency depends on the velocity of the crankshaft, and the AC voltage output depends on the crankshaft position and battery voltage. The CKP sensor works in conjunction with a 58X reluctor wheel attached to the crankshaft. The engine control module (ECM) can synchronize the ignition timing, fuel injector timing, and spark knock control based on the CKP and the camshaft position (CMP) sensor inputs. The CKP sensor is also used to detect misfire and tachometer display.

Conditions for Running the DTCs

    • DTCs P0340, P0341, P0641, or P0651 are not set.
    • The engine is cranking or running.
    • The DTC runs continuously once the above conditions are met.

Conditions for Setting the DTC

DTC P0335

The ECM does not detect a signal from the CKP sensor for greater than 3 seconds.

DTC P0336

    • The ECM detects an incorrect number of CKP reference pulses for 10 consecutive crankshaft revolutions.
    • The ECM detects that the engine is running, but more than 25 crankshaft resyncs have occurred within 25 seconds.

Action Taken When the DTC Sets

    • DTCs P0335, and P0336 are a Type B DTCs.
    • The engine will crank but not start.

Conditions for Clearing the DTC

DTCs P0335, and P0336 are a Type B DTCs.

Diagnostic Aids

The following conditions could also set the DTCs:

    • Physical damage to the CKP sensor or the reluctor wheel
    • Excessive play or looseness of the CKP sensor or the reluctor wheel
    • Improper installation of the CKP sensor or the reluctor wheel
    • Foreign material passing between the CKP sensor and the reluctor wheel
    • Excessive air gap between the CKP sensor and the reluctor wheel

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

    •  Engine Control Module Connector End Views
    •  Engine Controls Connector End Views

Electrical Information Reference

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

DTC Type Reference

Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Engine Control Module Scan Tool Information

Circuit/System Verification

    Important: If you were sent here from Engine Cranks but Does Not Run, proceed to Circuit/System Testing.

  1. Attempt to start the engine, observe the DTC information with a scan tool. DTCs P0335, or P0336 should not set.
  2. Engine cranking, observe the scan tool Engine Speed parameter. The scan tool should indicate an engine speed greater than 0 RPM.
  3. Move related harnesses/connectors of the CKP sensor and verify the engine does not stumble, stall, or change engine speed.
  4. 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. Test for less than 5 ohms between the low reference circuit terminal B 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, test for 4.8-5.2 volts between the 5-volt reference circuit terminal A 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. Test for 2-3 volts between the signal circuit terminal C 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. If all circuits test normal, test or replace the CKP sensor.

Component Testing

  1. Ignition OFF, disconnect the harness connector at the CKP sensor.
  2. Test for 500-700 ohms between the signal terminal A and low reference terminal B.
  3. If not within the specified range, replace the CKP sensor.
  4. Disconnect the fuel pump relay.
  5. Set the DMM to the AC voltage scale.
  6. Engine cranking, test for more than 500 mV AC between the signal terminal A and low reference terminal B.
  7. If less than the specified range, replace the CKP sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Crankshaft Position Sensor Replacement
    •  Engine Control Module Replacement for ECM replacement, setup, and programming