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 Circuit

P0651

P0335

P0651, P2135

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CKP Sensor Signal Circuit

P0335

P0335

P0335

P0336

Low Reference Circuit

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P0335

P0335

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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 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 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 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 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

    • DTC P0340, P0341, P0641 or P0651 is not set.
    • The engine is cranking or running.
    • 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 has been running, but has not received a CKP sensor pulse for 2 of 10 engine revolutions.

P0336

    • The ECM detects that the engine is running, but receives less than 51 or more than 65 CKP sensor pulses each engine revolution for 8 of 10 engine revolutions.
    • The ECM detects that the engine is running, but more than 19 resyncs occur within 25 seconds.
    • The ECM detects that the engine has been running, but the crankshaft does not sync for 0.4 second.

Action Taken When the DTC Sets

DTC P0335 and P0336 are type B DTCs.

Conditions for Clearing the MIL/DTC

DTC P0335 and P0336 are type B DTCs.

Diagnostic Aids

    • Inspect the CKP sensor connector and the ECM connector for corrosion.
    • With a DTC set, the engine may crank for an extended period of time at start-up.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

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

Description and Operation

    •  Engine Control Module Description
    •  Electronic Ignition (EI) System Description

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Scan Tool Data List

Circuit/System Verification

  1. With the ignition OFF, inspect the engine wiring harnesses carrying the CMP sensor circuits for the following conditions:
  2. • Close routing of secondary ignition wires
    • 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. Start the engine. Using the Live Plot function on the scan tool, select the CMP parameter. Change the minimum spec to 400 RPM and the maximum spec to 4,000 RPM. Select the CKP sensor parameter. Change the minimum spec to 600 RPM and the maximum spec to 3,300 RPM.
  4. Observe the scan tool.
  5. Quickly accelerate and release the accelerator pedal several times. Do not exceed 3,200 RPM. The 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 within the conditions that are captured in the Freeze Frame/Failure Records Data List.

Circuit/System Testing

P0335

  1. Ignition OFF, disconnect the CKP sensor connector.
  2. Test for less than 1 ohm between low reference circuit and ground.
  3. If greater than the specified value, 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 and ground.
  5. If less than the specified range, test the 5-volt reference circuit for a short to ground. 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, test for 4.8-5.2 volts between the signal circuit and ground.
  7. If less than the specified range, test the signal circuit for a open/high resistance, or short to ground. 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 ON, engine OFF, using a jumper wire connected to ground, momentarily touch the CKP sensor signal circuit repeatedly. The CKP Active Counter parameter should increment.
  9. If the CKP Active Counter parameter does not increment, replace the ECM.
    If the CKP Active Counter increments, test or replace the CKP sensor.

P0336

  1. Ignition OFF, inspect the CKP sensor for looseness and 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
    • Crankshaft reluctor wheel for damage
    • The timing chain, tensioner, and sprockets for wear or damage
         ⇒If debris is found in the engine oil, inspect the internal engine components to determine the cause. Repair or replace any worn or damage components. Refer to Camshaft Timing Chain and Sprocket Cleaning and Inspection and Crankshaft and Bearing Cleaning and Inspection .

Component Test

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

  1. Inspect the CKP sensor for looseness and correct installation. 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 ON the ignition, with the engine OFF.
  4. Observe the CKP Active Counter parameter on the scan tool. Pass a steel object by the tip of the sensor repeatedly. The CKP Active Counter parameter should increment.
  5. If the parameter does not increment, replace the CMP 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