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
--- | --- | --- | --- | ---
5-Volt Reference | P0335 | P0335 | -- | --
CKP Sensor Signal | P0335 | P0335 | P0335 | P0336
Low Reference | -- | P0335 | P0335 | --

### Circuit/System Description

The crankshaft position (CKP) sensor circuits consist of an engine control module (ECM) supplied 5-volt reference circuit, low reference circuit, and an output signal circuit. The CKP sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes of the teeth and slots of a 58-tooth reluctor wheel on the crankshaft. Each tooth on the reluctor wheel is spaced at 60-tooth spacing, with 2 missing teeth for the reference gap. The CKP sensor produces an ON/OFF DC voltage of varying frequency, with 58 output pulses per crankshaft revolution. The frequency of the CKP sensor output depends on the velocity of the crankshaft. The CKP sensor sends a digital signal, which represents an image of the crankshaft reluctor wheel, to the ECM as each tooth on the wheel rotates past the CKP sensor. The ECM uses each CKP signal pulse to determine crankshaft speed and decodes the crankshaft reluctor wheel reference gap to identify crankshaft position. This information is then used to determine the optimum ignition and injection points of the engine. The ECM also uses CKP sensor output information to determine the camshaft relative position to the crankshaft, to control camshaft phasing, and to detect cylinder misfire.

### Conditions for Running the DTC

• | DTC P0365, P0366, P0641 or P0651 is not set.

• | The engine is cranking or running.

• | These DTCs run continuously when the above conditions are met.

### Conditions for Setting the DTC

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

#### P0335

• | 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.

| OR

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

#### P0336

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

| OR

• | The ECM detects that the engine is running, but more than 20 resyncs occur within 25 seconds.

| OR

• | The ECM detects that the engine has been running, but the crankshaft does not sync for 0.4 second.

### 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.

### 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 OFF, inspect the engine wiring harnesses carrying the CKP sensor circuits for the following conditions:

• | Close routing of aftermarket electrical equipment

• | Close to solenoids, motors, and relays

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

2. Ignition ON, engine OFF, use the live plot function on the scan tool. Select the engine speed parameter and the CKP sensor 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 and observe the scan tool.
4. Quickly accelerate and release the accelerator pedal several times. Do not accelerate past 4,000 RPM. The two graphed lines on the live plot display should track together across the screen.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the CKP sensor.
2. Ignition OFF, test for less than 1 ohm between the low reference circuit terminal B and ground.

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

Note: 5K ohms or greater in the 5-volt reference circuit will cause this DTC to set.

3. Ignition ON, engine OFF, test for 4.8-5.2 volts between the 5-volt reference circuit terminal A 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 circuit tests normal, replace the ECM.

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

4. Ignition ON, engine OFF, test for 4.8-5.2 volts between the signal circuit terminal C 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.

5. Ignition OFF, connect a fused jumper wire to signal circuit terminal C.
6. Ignition ON, momentarily touch the other end of the fused jumper wire to the battery negative post repeatedly. The CKP Active Counter should increment.

⇒ | If the CKP Active Counter increments, test or replace the CKP sensor.

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

7. Ignition OFF, inspect the CKP sensor for correct installation. Remove the CKP sensor from the engine. Inspect the sensor and the O-ring for damage.

⇒ | If the sensor is loose, inspect the sensor and the O-ring for damage. Replace as necessary.

8. Inspect the engine for the following conditions:

• | Engine oil for debris

• | Crankshaft reluctor wheel for damage

• | Timing chain, tensioner, and sprockets for wear or damage

⇒ | If debris is found in the engine oil, inspect the internal engine components to determine the cause. Repair or replace any worn or damaged components.

9. If all circuits and components test normal, test or replace the CKP sensor.

### Component Testing

Note: You must perform the Circuit/System Testing before proceeding with Component Testing.

1. Remove the CKP sensor and inspect the sensor and the O-ring for damage.
2. Connect the connector to the CKP sensor.
3. Ignition ON, engine OFF, observe the CKP Active Counter while passing a steel object by the tip of the sensor repeatedly. The CKP Active Counter should increment.

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

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Control Module References

• | Crankshaft Position Sensor Replacement