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 Sensor Circuit Malfunction
DTC P0336: Crankshaft Position Sensor Signal Range/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
--- | --- | --- | --- | ---
CKP Sensor Signal | P0335 | P0335 | P0335 | P0336
Low Reference | -- | P0335 | P0335, P0338 | P0336
Shielded Ground | -- | -- | -- | P0336

### Circuit/System Description

The crankshaft position (CKP) sensor is located on the rear of bank 1 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, fuel injector timing and spark knock control based on the CKP sensor and the CMP sensor inputs. If the ECM loses the reference position to TDC, or the CKP signal is lost or erratic, one of these DTCs sets.

### Conditions for Running the DTC

• | The engine is cranking or operating

• | The ECM has detected greater than 12 camshaft revolutions

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

### Conditions for Setting the DTC

#### P0335

• | The ECM does not detect a signal from the CKP sensor. The condition exists for greater than 1 second or for a cumulative time of 10 seconds.

| OR

• | The ECM detects a CKP signal without a reference pulse for greater than 3 revolutions.

#### P0336

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

| OR

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

#### P0338

The ECM detects a difference of greater than 8 teeth between reference gap position pulses.

### Action Taken When the DTC Sets

DTCs P0335, P0336, P0337 and P0338 are type A DTCs.

### Conditions for Clearing the DTC

DTCs P0335, P0336, P0337 and P0338 are type A DTCs.

### Diagnostic Aids

The following conditions may also set the DTCs:

• | Physical damage to the CKP sensor or the reluctor wheel.

• | Incorrect play or looseness of the CKP sensor or the reluctor wheel.

• | Incorrect installation of the CKP sensor or the reluctor wheel.

• | Foreign material passing between the CKP sensor and the reluctor wheel.

• | Incorrect 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 hard restart. The ECM then calculates engine speed from one of the camshaft position sensors. During a limp home mode the following additional DTCs may set and should be ignored:

- | DTC P0324 Knock Sensor (KS) Module Performance.

- | DTC P1011 Intake Camshaft Position Actuator Park Position Bank 1.

• | 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

Camshaft Actuator 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, Using a scan tool clear all DTCs. Attempt to start the engine, observe the DTC information, DTC P0335, P0336 and P0338 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, remove the fuse that supplies B+ to circuit terminal 56 X2 of the ECM.
2. Disconnect the harness connector at the CKP sensor.

Notice: Do NOT use a test lamp to test the continuity of the circuit. Damage to the control module may occur due to excessive current draw.

Note: The ECM or the sensor may be damaged if the circuit is shorted to B+ voltage.

3. Test for less than 5 Ω between the low reference circuit terminal 1 and ground.

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

4. Install the fuse that supplies B+ to circuit terminal 56 X2 of the ECM.
5. Ignition ON, measure for 4.8-5.2 V between the 5 volt reference circuit terminal 3 of the CKP sensor and ground.

⇒ | If less than the specified range, test the 5 volt reference circuit for a short to ground or an open/high resistance. If the circuits/connections test normal, replace the ECM.

⇒ | If greater than the specified range, test the 5 volt reference circuit for a short to voltage. If the circuits/connections test normal, replace the ECM.

6. Measure for 4.8-5.2 V between the signal circuit of the CKP sensor terminal 2 and ground with a DMM.

⇒ | If greater than the specified range, test for a short to voltage in the signal circuit of the CKP sensor. If circuit/connections test normal, replace the ECM.

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

7. If all circuits/connections test normal, replace the CKP sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification .

• | Crankshaft Position Sensor Replacement

• | Engine Control Module Replacement for engine control module replacement, setup and programming.