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 Sensor Incorrect Signal
DTC P0336: Crankshaft Sensor Circuit Range/Performance

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
5-Volt Reference Circuit | P0641, P0651 | P0335 | P0651, P2135 | --
CKP Sensor Signal Circuit | P0335 | P0335 | P0335 | P0336
Low Reference | -- | P0335 | P0335 | --

### Typical Scan Tool Data

#### Engine Speed

Circuit | Normal Range | Short to Ground | Open | Short to Voltage
--- | --- | --- | --- | ---
Operating Conditions: Engine Running
5-Volt Reference Circuit | 400-6,400 RPM | 0 RPM | 0 RPM | 0 RPM
CKP Sensor Signal Circuit | 400-6,400 RPM | 0 RPM | 0 RPM | 0 RPM
Low Reference | 400-6,400 RPM | -- | 0 RPM | 0 RPM

### Circuit/System Description

The engine control module (ECM) uses the crankshaft position (CKP) sensor pulses to monitor the crankshaft position. The crankshaft reluctor wheel consists of a 60-tooth pattern with 2 teeth missing for the reference gap. Each tooth is evenly spaced 6 degrees apart, except for the reference gap. The engine control module (ECM) provides a 5-volt reference to the sensor a low reference circuit and a signal circuit. As the crankshaft rotates the reluctor trigger wheel interrupts a magnetic field provided by a magnet internal to the sensor. The CKP sensor internal circuitry detects this interruption of the magnetic field and produces an ON/OFF DC voltage of varying frequency. The frequency of the CKP sensor output signal is dependent upon crankshaft speed. The ECM uses each CKP output signal to determine crankshaft speed and identify crankshaft position. The information from the CKP sensor and other engine sensors is used to determine the optimum fuel injection and ignition system timing events for efficient engine operation. The ECM also uses the CKP sensor output information to determined the camshaft relative position to the crankshaft position, cylinder misfire and if equipped to control the intake and exhaust valve timing through the camshaft actuator assembly.

### Conditions for Running the DTC

• | DTC P0340, P0341, P0641, or P0651 is not set.

• | The engine is cranking or running.

• | The DTC runs continuously when the above conditions are met.

### Conditions for Setting the DTC

#### P0335

| Important: The ECM detects engine movement by sensing the airflow through the mass air flow (MAF) sensor is more than 3 g/s, or by sensing camshaft position (CMP) sensor pulses.

• | The ECM detects that the starter is commanded ON, and the engine has been cranking for more than 4 seconds without a CKP sensor pulse.

• | The ECM detects that the engine has been running but has not received a CKP sensor pulse for 2 out of 10 engine revolutions.

#### P0336

| Important: The ECM detects engine movement by sensing the airflow through the mass air flow (MAF) sensor is more than 3 g/s or by sensing CMP sensor pulses.

• | The ECM detects that the engine is running but receives less than 51 or more than 65 CKP sensor pulses during each engine revolution, for 8 of 10 engine revolutions.

• | The ECM detects that the engine is running but more than 19 crankshaft resyncs have occur within 25 seconds.

### Action Taken when the DTC Sets

DTC P0335 or P0336 are type B DTC

### Conditions for Clearing the MIL/DTC

DTC P0335 or P0336 are type B DTC.

### Diagnostic Aids

• | This test procedure requires that the vehicle battery has passed a load test and is completely charged.

• | When disconnecting harness connectors or removing fuses and relays from a fuse block, always inspect the component electrical terminals for corrosion and the mating electrical terminals for tightness.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References

### Circuit/System Verification

1. With the engine running, using a scan tool observe the Engine Speed parameter and the Crankshaft Position (CKP) sensor active count parameter. The CKP sensor parameter should closely match the Engine Speed parameter.

⇒ | If the CKP sensor is zero or grossly different from the Engine Speed parameter then continue with the Circuit/System Testing.

2. Ignition ON, engine OFF, using the snap shot function on the scan tool. Select the Engine Speed parameter and the CKP Sensor active count parameter. Change the minimum spec to 400 RPM for both parameters. Change the maximum spec to 4,000 RPM for both parameters.
3. Start the engine.
4. Observe the scan tool.
5. Quickly accelerate and release the accelerator pedal several times. Do not accelerate pass 4,000 RPM. The 2 graph lines on the live plot displayed, should track together across the screen.

⇒ | If the CKP sensor plot line changes from the Engine Speed plot line, continue with the Circuit/System Testing.

⇒ | If the vehicle passes the above Circuit/System Verification Tests, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List. Another option is to refer to Testing for Intermittent Conditions and Poor Connections.

### Circuit/System Testing

1. Ignition OFF, inspect the CKP sensor engine wire harness circuits for the following conditions:

• | Close routing of secondary ignition wires.

• | Close routing of aftermarket electrical equipment.

• | Close to motors, solenoids, and relays.

⇒ | Correct any wire routing or component placement conditions, if is determined to be a possible source of electrical interference.

2. Disconnect the CKP sensor wire harness connector. Inspect the harness connector for corrosion and for proper terminal tension. Repair as necessary.
3. Ignition ON, engine OFF, measure for 4.8-5.2 volts between the 5-volt reference circuit at the CKP wire harness connector and a known ground.

⇒ | If the voltage is less than 4.8 volts, test for a short to ground or an open/high resistance in the 5-volt reference circuit between the ECM and the CKP sensor connector. If the circuit tests normal, replace the ECM.

4. Ignition ON, engine OFF. Measure for 4.8-5.2 volts at the CKP sensor signal circuit on the CKP wire harness connector and a known ground.

⇒ | If the voltage is less than 4.8 volts, test for an short to ground or an open/high resistance in the CKP sensor signal circuit between the ECM and the CKP sensor wire harness connector. If the circuit tests normal, replace the ECM.

⇒ | If the voltage is more than 5.2 volts, test for a short to voltage in the CKP sensor signal circuit between the ECM and the CKP sensor wire harness connector. If the circuit tests normal, replace the ECM.

5. Ignition ON, engine OFF. Measure for 1-3 mA of current, between the CKP sensor signal circuit and a known ground at the CKP wire harness connector.

⇒ | If the amperage is more than 3 mA, test the CKP sensor signal circuit for a short to the 5-volt reference circuit between the ECM and the CKP sensor connector. If the circuit tests normal, replace the ECM.

6. Connect a 3-A fusible link wire to a known ground.
7. Ignition ON, engine OFF. Observe the CKP Active Counter parameter on the scan tool.
8. Touch the jumper wire to the CKP sensor signal circuit repeatedly at the connector. The CKP Active Counter parameter should increment.

⇒ | If the CKP Active Counter parameter does not increment, replace the ECM.

9. Ignition ON, engine OFF. Measure for B+ at the low reference circuit on the CKP sensor wire harness connector and the battery positive post.

⇒ | If the voltage measured between the low reference circuit and the battery positive post is not the same as the voltage measured between a known ground and the battery post, then test for an open/high resistance in the low reference circuit between the ECM and the CKP sensor connector. If the circuit tests normal, replace the ECM.

10. Ignition OFF, inspect the CKP sensor for looseness. Remove the CKP sensor from the engine. Inspect the CKP sensor and the O-ring for damage. Refer to Crankshaft Position Sensor Replacement. Replace the CKP sensor if necessary.
11. Reconnect the CKP wire harness connector to the CKP sensor.
12. Ignition ON, engine OFF.
13. While observing the CKP Active Counter parameter on the scan tool pass a small flat steel object by the tip of the CKP sensor repeatedly. The CKP Active Counter parameter should increment.

⇒ | If the parameter remains at zero or another fixed value, replace the CKP sensor.

14. Ignition OFF, remove the engine oil pan, refer to Oil Pan Replacement and inspect the engine oil for debris and the crankshaft reluctor wheel for damage or debris stuck onto the teeth of the reluctor wheel.

⇒ | If debris is found in the engine oil, inspect the engine components to determine the cause.

⇒ | If the crankshaft reluctor wheel is damaged, replace the crankshaft.

15. Ignition OFF, remove the engine front cover. Refer to Engine Front Cover Replacement . Inspect the timing chain, tensioner and sprockets for wear or damage. Refer to Camshaft Timing Chain and Sprocket Cleaning and Inspection.

⇒ | If any parts are worn or damaged, replace as necessary.

### 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