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 provide an overview of each diagnostic category.

DTC Descriptor

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

P0641, P0651

P0335

P0651, P2135

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CKP Sensor Signal Circuit

P0335

P0335

P0335

P0336

Low Reference Circuit

--

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 between the peaks and valleys 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 sequence the ignition timing and fuel injection events for the engine. The ECM also uses CKP sensor output information to determine the crankshaft relative position to the camshaft, to detect cylinder misfire, and to control the camshaft position (CMP) actuator if equipped.

Conditions for Running the DTC

    • DTC 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 MAF sensor, when airflow is greater than 3 grams per second, or by sensing CMP sensor pulses.

    • The ECM detects that the engine is running, but receives less than 55 or more than 61 CKP sensor pulses, during each engine revolution, for 8 of 10 engine 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

    • DTC P0336 is a Type B DTC.
    • The CMP actuator if equipped is commanded to the parked position.

Conditions for Clearing the DTC

DTC P0336 is a Type B DTC.

Diagnostic Aids

    • With a DTC set, the engine may crank for an extended period of time during start-up.
    • This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to Battery Inspection/Test .

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

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

    •  Scan Tool Data List
    •  Scan Tool Data Definitions
    •  Scan Tool Output Controls

Circuit/System Verification

  1. Ignition OFF, inspect the engine wiring harness 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. Start the engine. Using the live plot function on the scan tool, select the CMP sensor 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 accelerate pass 3,200 RPM. The graphed lines on the live plot display should track together across the screen.
  6. 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

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

  1. Ignition OFF, disconnect the harness connector at the CKP sensor.
  2. Test for less than 1 ohm of resistance between the CKP low reference circuit terminal B 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 OFF, inspect the CKP sensor for correct installation.
  5. If the CKP sensor is loose, inspect the sensor and the O-ring for damage, replace as necessary.
    If any parts are worn or damaged, replace as necessary.

Component Testing

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

  1. Inspect the CKP sensor for correct installation. Remove the CKP sensor from the engine and inspect the sensor O-ring for damage.
  2. If the sensor is loose, incorrectly installed, or damaged, replace the CKP sensor.
  3. Connect the CKP sensor harness connector to the CKP sensor.
  4. Ignition ON, engine OFF. Observe the CKP Active counter parameter on the scan tool.
  5. Pass a flat steel object across the tip of the sensor repeatedly. The CKP Active counter parameter should increment with each pass of the steel object.
  6. If the parameter does not increment, replace the CKP sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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