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
--- | --- | --- | --- | ---
CKP Sensor Signal | P0335 | -- | -- | P0336
Low Reference | P0335 | -- | -- | 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:

• | The signal

• | The low reference

• | The shielded ground

### Conditions for Running the DTC

#### P0335

• | The engine is cranking or running.

• | The DTC runs continuously once the above condition is met.

#### P0336

• | The engine speed is greater than 512 RPM.

• | The DTC runs continuously once the above condition is met.

### Conditions for Setting the DTC

#### P0335

The ECM does not detect a signal from the CKP sensor.

#### P0336

The ECM detects greater than 2 pulses incorrect at each reference pulse.

### 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

### 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. Attempt to start the engine. Observe the DTC information with a scan tool. DTCs P0335 and P0336 should not set.
2. Move related harnesses/connectors of the CKP sensor. 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 CKP sensor.
2. Ignition ON, test for 1.5-3.0 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 1.5-3.0 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. Test for 460-620 ohms between the signal terminal 1 and low reference terminal 2.

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

3. Disconnect the fuel pump relay.
4. Engine cranking, test for greater than 1.4 ACV between the signal terminal 1 and 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.

• | Crankshaft Position Sensor Replacement

• | Control Module References for engine control module replacement, setup, and programming