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

The 5-Volt Reference Circuit

P0335, P0651, P2135

P0335, P0336

P0651

--

CKP Sensor Signal

P0335

P0335

P0335

--

Low Reference Circuit

P0335

P0335

--

--

Circuit 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 internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes of the teeth and slots of a 58-tooth reluctor wheel on the crankshaft. Each tooth on the reluctor wheel is spaced at 60-tooth spacing, with 2 missing teeth for the reference gap. The CKP sensor produces an ON/OFF DC voltage of varying frequency, with 58 output pulses per crankshaft revolution. The output frequency of the CKP sensor depends on the speed of the crankshaft. The CKP sensor sends a digital signal, which represents an image of the crankshaft reluctor wheel, to the ECM as each tooth on the wheel rotates past the CKP sensor. The ECM uses each CKP signal pulse to determine crankshaft speed and decodes the crankshaft reluctor wheel reference gap to identify crankshaft position. This information is then used to sequence the ignition timing and fuel injection events of the engine. The ECM also uses CKP sensor output information to determine the camshaft relative position to the crankshaft, to control camshaft actuator, and to detect cylinder misfire.

Conditions for Running the DTC

P0335

    • DTC P0340, P0341, P01641 or P0651 are not set.
    • The engine is cranking or running.
    • The CMP sensor pulses is received or intake MAF is more than 3 g/s.
    • The DTC runs continuously when the above conditions are met.

P0336

    • DTC P0340, P0341, P0641 or P0651 is not set.
    • The engine is cranking or running.
    • The engine speed is more than 450 RPM.
    • The DTC runs continuously when the above conditions are met.

Conditions for Setting the DTC

Important: The ECM detects engine movement by sensing the airflow through the mass air flow (MAF) sensor is more than 3 g/s, or by sensing CMP sensor pulses.

P0335

    • The ECM detects that the starter is commanded ON and the engine has been cranking for more than 4 seconds without a CKP sensor pulse.
    • The ECM detects that the engine is running, but not receive a CKP sensor pulse for 2 of 10 engine revolutions.
    • The ECM does not detect the CKP sensor synchronization.

P0336

    • The ECM detects that the engine is running, but receives less than 55 or more than 61 CKP sensor pulses each engine revolution for 8 of 10 engine revolutions.
    • The ECM detects that the engine is running, but more than 20 resynchronize occur within 25 seconds.

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.

Diagnostic Aids

This test procedure requires that the vehicle battery has passed a load test and is completely charged.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

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

Description and Operation

Electronic Ignition (EI) System Diagnosis

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

    •  Scan Tool Data List
    •  Scan Tool Data Definitions
    •  Engine Control Module Scan Tool Information

Circuit/System Verification

  1. With the ignition OFF, inspect the engine wiring harnesses carrying the CKP sensor circuits for the following conditions:
  2. • Close routing of aftermarket electrical equipment
    • Close to solenoids, motors, and relays
    Correct any wire harness routing or component placement conditions, if it is determined to be a possible source of electrical interference.
  3. With the engine OFF, turn the ignition ON, use the Live Plot function on the scan tool. Select the engine speed parameter and the CKP sensor parameter. Change the minimum specification to 400 RPM for both parameters. Change the maximum specification to 4,000 RPM for both parameters.
  4. Start the engine, and observe the scan tool.
  5. Quickly accelerate and release the accelerator pedal several times. Do not accelerate exceed 4,000 RPM. The 2 graphed lines on the Live Plot display should track together across the screen.
  6. If the vehicle passes the Circuit/System Verification Test, operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle under the conditions observed from the Freeze Frame/Failure Records.

Circuit/System Testing

P0335

  1. Ignition OFF, disconnect the 8-way harness connector C104.
  2. Test for less than 1 ohm between low reference circuit terminal A and ground on the ECM side of the connector.
  3. If more than the specified values, test the low reference circuit for an open/high resistance. If the circuit test normal, replace the ECM.
  4. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal C and ground on the ECM side of the connector.
  5. If less than the specified range, test the 5-volt reference circuit for an open, high resistance or short to ground. If the circuit test normal, replace the ECM.
    If greater than the specified range, test the 5-volt reference circuit for short to voltage. If the circuit test normal, replace the ECM.
  6. Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal B and ground on the ECM side of the connector.
  7. If less than the specified range, test the affected signal circuit for an open, high resistance or short to ground. If the circuit test normal, replace the ECM.
    If greater than the specified range, test the affected signal circuit for a short to voltage. If the circuit test normal, replace the ECM.
  8. Ignition OFF, connect a fused jumper wire to the CKP signal circuit terminal B on the ECM side of the connector.
  9. Ignition ON, momentarily touch the other end of the fused jumper wire to the battery negative post. The CKP active counter parameter on the scan tool should increase.
  10. If the CKP active counter parameter does not increase, replace the ECM.
  11. Ignition OFF, inspect the wiring harness, from the 8-way connector C104 to the CKP sensor, for any damage, open, or short.
  12. If the circuits test normal, replace the CKP sensor.

P0336

  1. Ignition OFF, inspect the CKP sensor for correct installation.
  2. If the sensor is loose, inspect the sensor and the O-ring for damage, replace as necessary.
  3. Inspect the engine for the following conditions:
  4. • Engine oil for debris
    • A damaged crankshaft reluctor wheel
    • The timing chain, tensioner and sprockets for wear or damage

Component Testing

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

  1. Inspect the CKP sensor for being installed correctly. Remove the CKP sensor from the engine and inspect the sensor and the O-ring for damage.
  2. If the sensor is loose, incorrectly installed, or damaged, repair or replace the CKP sensor.
  3. Connect the CKP Sensor connector to the CKP sensor. Turn the ignition ON with the engine OFF.
  4. Ignition ON, engine OFF. Observe the CKP Active Counter while passing a steel object across the tip of the sensor repeatedly. The CKP Active Counter parameter should increment.
  5. If the parameter does not increase, replace the CKP sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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