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
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, P0698, P2127 | P0335 | P0335, P0338, P0699 | P0336, P0698, P0699
CKP Sensor Signal | P0122, P0222, P0335, P0698, P2127 | P0335 | P0335, P0338, P0699 | P0336, P0698, P0699
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

• | The engine is cranking or operating.

• | The ECM has detected greater than 12 camshaft revolutions.

• | DTC P0335 and P0336 run continuously when the above conditions are met for greater than 5 seconds.

• | DTC P0338 runs once each engine revolution when the above conditions are met for greater than 2 seconds.

### 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 1 second or a cumulative of 10 seconds.

#### P0336

• | The ECM re-syncs the engine position 6 or more times during an ignition cycle.

| OR

• | The ECM detects 28 or more interruptions in the engine speed signal during an ignition cycle.

• | The ECM detects either condition for greater than 1 second or a cumulative of 10 seconds.

#### P0338

The ECM detects a difference of greater than 8 teeth between reference gap position pulses for greater than 1 second or a cumulative of 10 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

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.

• | The engine will operate with a CKP sensor condition only if the ECM has stored the learned reference position of the camshafts in memory. With a crankshaft position sensor condition the engine will go into a limp home mode after a restart. The ECM then calculates engine speed from one of the camshaft position sensors.

• | An intermittent condition in the camshaft position (CMP) sensor circuits can cause a CKP DTC to set. Inspect the CMP sensor, harness connections, and related wiring, if you suspect this condition.

### 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. Ignition ON, observe the DTC information with a scan tool. DTC P0697, P0698, or P0699 should not be set.

⇒ | If a DTC is set, refer to DTC P0641-P0643, P0651-P0653, or P0697-P0699.

2. Clear the DTC Info with a scan tool. Attempt to start the engine, observe the DTC information with a scan tool. DTC P0335, P0336, or P0338 should not set.
3. Observe the scan tool CKP Resync parameter. The parameter should always display zero. Move the related harnesses/connectors of the CKP sensor while observing the parameter. Verify the engine does not stumble or stall, and the parameter does not increment.
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

1. Ignition OFF, remove the fuse that supplies B+ to terminal 56-X2 of the ECM.
2. Disconnect the harness connector at the crankshaft position (CKP) sensor.
3. Test for 5 Ω or less between the low reference circuit terminal 1 and ground.

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

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

⇒ | If less than the specified value, test for an open/high resistance in the 5-volt reference circuit. 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 the voltage is greater than specified range, test for a short to voltage in the signal circuit. If circuit/connections test normal, replace the ECM.

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

• | Crankshaft Position Sensor Replacement

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