Diagnostic Instructions

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, P0697, P2127	P0335	P0335, P0338, P0697	P0336, P0697
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

Conditions for Setting the DTC

P0335

The ECM does not detect a signal from the CKP sensor. OR, the ECM detects a CKP signal with out 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 more times during an ignition cycle. OR, the ECM detects 14 or more 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 for 4 consecutive crankshaft revolutions in which the same number of pulses are detected each crankshaft revolution 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

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

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 DTC Info with a scan tool. Attempt to start the engine, observe the scan tool DTC information parameter. 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 OFF, disconnect the harness connector at the crankshaft position (CKP) sensor.
2. Remove the fuse that supplies B+ to terminal X2-56 of the ECM.
3. Test for less than 5 ohms between the low reference circuit terminal 1 and ground.

⇒	If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuits/connections test normal, replace the ECM.

4. Install the fuse that supplies B+ to terminal X2-56 of the ECM.
5. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 and the low reference circuit terminal 1.

⇒	If less than the specified range, test the 5-volt reference circuit for an open/high resistance. If the circuits/connections test normal, replace the ECM.

6. Test for 4.8-5.2 volts between the signal circuit terminal 2 and ground.

⇒	If greater than specified range, test the signal circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.

Important: The signal circuit voltage can be within the specified range with a high resistance in the circuit. If this condition is suspected, refer to Diagnostic Aids.

⇒	If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit/connections test normal, replace the ECM.

7. If all circuits/connections test normal, test or replace the CKP sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.