Diagnostic Instructions

DTC Descriptors

DTC P0336: Crankshaft Position (CKP) Sensor Performance

DTC P0337: Crankshaft Position (CKP) Sensor Circuit Low Duty Cycle

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
CKP Sensor Signal	--	P0337	--	P0336
Low Reference	--	P0337	--	P0336
Shielded Ground	--	--	--	P0336

Circuit/System Description

The crankshaft position (CKP) sensor signal indicates the crankshaft speed and position. The CKP sensor produces an AC voltage of different amplitude and frequency. The frequency depends on the velocity of the crankshaft, and the AC voltage output depends on the crankshaft position and battery voltage. The CKP sensor works in conjunction with a 58X reluctor wheel attached to the crankshaft. The engine control module (ECM) can synchronize the ignition timing, fuel injector timing, and spark knock control based on the CKP and the camshaft position (CMP) sensor inputs. The CKP sensor is also used to detect misfire and tachometer display. The CKP sensor circuits are connected directly to the ECM. The circuits between the CKP sensor and the ECM consist of the following circuits:

Conditions for Running the DTC

Conditions for Setting the DTC

P0336

The ECM detects an incorrect number of CKP reference pulses for 10 consecutive crankshaft revolutions.

P0337

The ECM does not detect a signal from the CKP sensor for greater than 8 seconds.

Action Taken When the DTC Sets

Conditions for Clearing the DTC

Diagnostic Aids

The following conditions could also set the DTCs:

Reference Information

Schematic Reference

Engine Controls Schematics

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. Attempt to start the engine, observe the DTC information with a scan tool. DTCs P0336 and P0337 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 you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

Important: If the CKP sensor lead is damaged in any way, replace the CKP sensor.

1. Ignition OFF, disconnect the harness connector at the crankshaft position (CKP) sensor.
2. Ignition ON, test for 1.5-2.0 volts between the signal circuit terminal 1 and ground.

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

3. Ignition ON, test for 1.5-2.0 volts between the low reference circuit terminal 2 and ground.

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

⇒	If greater than the specified range, test the low reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.

4. If all circuits test normal, test or replace the CKP sensor.

Component Testing

1. Ignition OFF, disconnect the harness connector at the CKP sensor.

Important: If the CKP sensor lead is damaged in any way, replace the CKP sensor.

2. Connect a DMM between the signal terminal 1 and the low reference terminal 2.
3. Test for 460-620 ohms of resistance between the signal terminal 1 and the low reference terminal 2.

⇒	If not within the specified range, replace the CKP sensor.

4. Disconnect the fuel pump relay.
5. Set the DMM to the AC voltage scale.
6. Engine cranking, test for greater than 1.4 ACV between the signal terminal 1 and the low reference terminal 2.

⇒	If less than the specified range, replace the CKP sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.