GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2008 🢒 LaCrosse 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC P0335, P0336, or P0338

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

DTC P0338: Crankshaft Position (CKP) Sensor Circuit High Duty Cycle

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

5-Volt Reference

P0122, P0222, P0335, P2127

P0335

P0335, P0338

P0336

CKP Sensor Signal

P0122, P0222, P0335, P2127

P0335

P0335, P0338

P0336

Low Reference

P0335

P0335

--

P0336

Circuit/System Description

The crankshaft position (CKP) sensor is located on the rear of bank 1 of the engine block. The CKP sensor is a hall effect switch that works in conjunction with a 58X reluctor wheel that is attached to the crankshaft. Each tooth on the reluctor wheel is spaced 6 degrees apart with one span having a 12 degree space. The engine control module (ECM) uses the 12 degree space to determine top dead center (TDC) for cylinders 1 and 4. The ECM determines when cylinder 1 is on the compression stroke by monitoring the CKP sensor and the camshaft position (CMP) sensors. The ECM can synchronize the ignition timing, fuel injector timing, and spark knock control based on the CKP sensor and the CMP sensor inputs.

Conditions for Running the DTC
    • The engine is cranking or operating.
    • The ECM has detected greater than 12 camshaft revolutions.
    •  The DTCs P0335 and P0336 run continuously once the conditions above are met for greater than 5 seconds.
    • DTC P0338 runs once per revolution when the condition above are met for greater than 2 seconds.

Conditions for Setting the DTC

P0335

    • The ECM does not detect a signal from the CKP sensor.
        OR
    • The ECM detects a CKP signal without reference pulse for greater than 3 revolutions.
    • Either condition exists for greater than 4 seconds or a cumulative of 50 seconds.

P0336

    • The ECM re-syncs the engine position 6 or greater times during an ignition cycle.
        OR
    • The ECM detects 28 or greater interruptions in the engine speed signal during an ignition cycle.
    •  Either condition exists for greater than 4 seconds or a cumulative of 50 seconds.

P0338

    • The ECM detects a difference of greater than 8 teeth between reference gap position pulses.
    • The condition exists for greater than 4 seconds, or a cumulative of 50 seconds.

Action Taken When the DTC Sets

DTCs P0335, P0336, and P0338 are Type A DTCs.

Conditions for Clearing the DTC

DTCs P0335, P0336, and P0338 are Type A 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
    • The ECM uses the camshaft position sensors to determine engine speed and position when there is a CKP sensor condition.
    • The engine will operate with a CKP sensor condition only if the ECM has stored the learned reference position of the camshafts in memory. With a crankshaft position sensor condition the engine will go into a limp home mode after a restart. The ECM then calculates engine speed from one of the camshaft position sensors. During a limp home mode the following additional DTCs may set and should be ignored:
       - DTC P0324 Knock Sensor (KS) Module Performance
       - DTC P1011 Intake Camshaft Position Actuator Park Position Bank 1
    • An intermittent condition in the camshaft position (CMP) sensor circuits can cause a CKP DTC to set. Inspect the CMP sensor, harness connections, and related wiring, if you suspect this condition.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component 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

Control Module References for scan tool information

Circuit/System Verification
  1. Ignition ON, clear the diagnostic trouble code (DTC) information with a scan tool. Attempt to start the engine, observe the scan tool DTC information. DTC P0335, P0336, or P0338 should not set.
  2. Move related harnesses/connectors of the CKP sensor and verify the engine does not stumble, stall, or change engine speed.
  3. 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 are captured in the Freeze Frame/Failure Records Data List.

Circuit/System Testing
  1. Ignition ON, clear the DTCs with a scan tool.
  2. Engine idling, raise the engine speed to 1,000 RPM for 30 seconds, and then return to idle. Move the related CKP harnesses and connectors between the CKP and the ECM. Verify the engine does not stall or stumble.
    3. ⇒If the engine stalls or stumbles, repair the harness/connections as necessary.
  3. Ignition OFF, inspect the CKP harness for the following:
    4. • Routed too close to the battery or the battery cables
    • Routed too close to other wiring or components
    • Routed too close to after market add on electrical equipment
    • Routed too close to solenoids, relays, and motors
    ⇒If a condition is located, repair as necessary.
  4. Disconnect the harness connector at the CKP sensor.
  5. Ignition ON, test for 2-3 volts between the signal circuit terminal 2 and ground.
    6. ⇒If less than the specified range, test the signal circuit for a short to ground, or an open/high resistance. If the circuits/connections test normal, replace the ECM.
    ⇒If greater than the specified range, test the signal circuit for a short to voltage. If the circuits/connections test normal, replace the ECM.
  6. Test for 2-3 volts between the low reference circuit terminal 1 and ground.
    7. ⇒If less than the specified range, test the low reference circuit for a short to ground or an open. If the circuit/connections test normal, replace the ECM.
    ⇒If greater than the specified range, test the low reference circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.
  7. Remove the CKP sensor--Refer to Crankshaft Position Sensor Replacement .
  8. Inspect the crankshaft reluctor wheel for damage.
    9. ⇒If the crankshaft reluctor wheel is damaged--Refer to Crankshaft and Bearing Cleaning and Inspection , and replace the CKP sensor.
  9. If all circuits/connections test normal, test or replace the CKP sensor.

Component Testing
  1. Ignition OFF, disconnect the harness connector at the CKP sensor.
  2. Test for 700-1,200 ohms of resistance between the signal circuit and low reference circuit of the CKP sensor.
    3. ⇒If not within the specified range, replace the CKP sensor.
  3. Disconnect the fuel pump relay.
  4. Set the DMM to the AC voltage scale.
  5. While cranking the engine, test for greater than 1.3 VAC between the signal circuit and low reference circuit of the CKP sensor.
    6. ⇒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
    •  Control Module References for engine control module replacement, setup, and programming