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 Descriptor

DTC P0335: Crankshaft Position (CKP) Sensor Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

5-Volt Reference Circuit

P0335, P0651, P2135

P0335, P0336

P0651

--

CKP Sensor Signal Circuit

P0335

P0335

P0335

--

Low Reference Circuit

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 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 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 the camshaft actuator, 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.

    •  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.
        OR
    • The ECM detects that the engine has been running, but has not received a CKP sensor pulse for 2 of 10 engine revolutions.

Action Taken When the DTC Sets

DTC P0335 is a Type B DTC.

Conditions for Clearing the DTC

DTC P0335 is a Type B DTC.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component 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

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for 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 ignition ON, and the engine OFF, use the live plot function on the scan tool. Select the engine speed parameter and the CKP sensor parameter. Change the minimum spec to 400 RPM for both parameters. Change the maximum spec 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 past 4,000 RPM. The two 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 you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

  1. Ignition OFF and scan tool disconnected for 90 seconds, disconnect the X104 inline harness connector.
  2. Test for less than 1 ohm between low reference circuit terminal A on the ECM side of the connector 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 terminal C on the ECM side of the connector and ground.
  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 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 terminal B on the ECM side of the connector and ground.
  7. If less than the specified range, test the affected signal circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the ECM.
    If greater than the specified range, test the affected signal circuit for a short to voltage. If the circuit tests 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 negative battery post. The CKP Active Counter parameter on the scan tool should increment.
  10. If the CKP Active Counter parameter does not increment, replace the ECM.
  11. Ignition OFF, inspect the wiring harness, from the X104 inline harness connector to the CKP sensor, for any damage, opens, or shorts.
  12. If the circuits test normal replace the CKP sensor.

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 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.
  4. Ignition ON and 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 increment, replace the CKP sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Crankshaft Position Sensor Replacement
    •  Control Module References