For 1990-2009 cars

### 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

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
5-Volt Reference | P0335 | P0335 | -- | P0336
CKP Sensor Signal | P0335 | P0335 | -- | P0336
Low Reference | -- | -- | -- | P0336

### 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 determine the optimum ignition and injection points of the engine. The ECM also uses CKP sensor output information to determine the camshaft relative position to the crankshaft, to control camshaft phasing, and to detect cylinder misfire.

### Conditions for Running the DTC

• | DTCs P0011, P0012, P0014, P0015, P0016, P0017, P0340 and P0341 are not set.

• | The engine is cranking or running.

• | The DTCs run continuously once the above conditions are met.

### Conditions for Setting the DTC

#### DTC P0335

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

#### DTC P0336

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

### Action Taken When the DTC Sets

• | DTC P0335 is a Type A DTC.

• | DTC P0336 is a Type B DTC.

• | The ECM will use the camshaft position (CMP) sensor for engine operation.

### Conditions for Clearing the DTC

• | DTC P0335 is a Type A DTC.

• | DTC P0336 is a Type B DTC.

### 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

### 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

Important: If you were sent here from Engine Cranks but Does Not Run, proceed to Circuit/System Testing.

1. Attempt to start the engine, observe the DTC information with a scan tool. DTC P0335 and P0336 should not set.
2. Engine cranking, observe the scan tool Engine Speed parameter. The scan tool should indicate an engine speed greater than 0 RPM.
3. Move related harnesses/connectors of the CKP sensor and verify the engine does not stumble, stall, or change engine speed.
4. 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 CKP sensor.
2. Ignition OFF, test for 5 ohms or less of resistance between the low reference circuit terminal 1 and ground.

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

3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 2 and ground.

⇒ | If less than the specified range, test the 5-volt reference circuit for a short to ground or open/high resistance. 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.

4. Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal 3 and the 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.

5. If all circuits test normal, test or replace the crankshaft position sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Crankshaft Position Sensor Replacement

• | Control Module References for ECM replacement, setup, and programming