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 Descriptor

DTC P0335: Crankshaft Position (CKP) Sensor Circuit
DTC P0335 28: Crankshaft Position (CKP) Sensor Circuit Incorrect Frequency
DTC P0335 29: Crankshaft Position (CKP) Sensor Circuit Too Few Pulses
DTC P0336: Crankshaft Position (CKP) Sensor Circuit Performance

### Circuit/System Description

The crankshaft position (CKP) sensor is located on the left rear of the engine block. The CKP sensor produces an AC voltage of different amplitude and frequency depending on the velocity of the crankshaft. The CKP sensor works in conjunction with a 58X reluctor wheel that is attached to the crankshaft. Each tooth on the reluctor wheel are 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 and fuel injector timing based on the CKP sensor and the CMP sensor inputs.

### Conditions for Running the DTC

• | The engine is cranking or running.

• | The DTCs run continuously once the above condition is met for greater than 5 seconds.

### Conditions for Setting the DTC

#### P0335, P0335 29

The ECM does not detect a signal from the CKP sensor. OR, the ECM detects a CKP signal without reference pulse.

#### P0335 28, P0336

The ECM re-syncs the engine position during an ignition cycle.

### Action Taken When the DTC Sets

DTCs P0335 and P0336 are Type B DTCs.

### Conditions for Clearing the DTC

DTCs P0335 and P0336 are Type B 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.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### 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. Clear the DTC Info with a scan tool. Attempt to start the engine, observe the DTC information with a scan tool. DTCs P0335 or P0336 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

1. Ignition OFF, disconnect the harness connector at the crankshaft position (CKP) sensor.
2. Ignition ON, test for 2-3 volts between the high signal circuit terminal 1 and ground.

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

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

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

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

⇒ | If greater than the specified range, test the low signal 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 crankshaft position (CKP) sensor.

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

2. Test for 700-1200 ohms of resistance between the high signal terminal 1 and the low signal terminal 2.

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

3. Set the DMM to the AC voltage scale.
4. Engine cranking, test for greater than 1.3 ACV between the high signal terminal 1 and the low signal terminal 2.

⇒ | 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 ECM replacement, setup, and programming