The most common problem when the P0339 code occurs is a problem with the crankshaft position sensor or incorrect wiring of it. But do not simply replace the parts! Read the article and I will explain how to diagnose it correctly and repair it at the lowest cost.
In this article, you will find information about what the P0339 code means and what the most common problems are to solve it in the fastest and cheapest way.
What does the P0339 code mean?
Error code P0339 is triggered when the engine control unit receives an intermittent high signal (voltage) or an error signal from the crankshaft sensor ‘A’. The function of the crankshaft sensor is to read where the crankshaft is in the cycle. It is used to know when the injectors and ignition coils need to be ignited. The RPM will also be displayed on your dashboard by the crankshaft sensor.
Because of the important function of the crankshaft sensor, your engine may stop while you are driving and not start again when you receive this error code. The signal from the crankshaft sensor is necessary to get the engine running, and the control unit may not be able to open your injectors and ignite the spark plugs if it receives an incorrect signal from the crankshaft sensor.
What is the function of the crankshaft sensor?
The crankshaft sensor is often mounted on the front or rear of the engine. On some vehicles, it reads the signal from the clutch flywheel and can be attached to the transmission housing. It can also be mounted on the front harmonic balancer and read the signal from a trigger wheel (see picture). The trigger wheel is missing a tooth, so the crankshaft sensor knows when the engine has made a full turn.
The crankshaft sensor can also be mounted on your engine block and read the signal internally from the crankshaft in the engine block.
Sometimes, if the harmonic balancer, flywheel or internal trigger wheel is defective, this can damage the crankshaft sensor and cause the engine ECU to trigger the P0339. If you receive this fault code, visually inspect the crankshaft sensor if possible.
The most common symptom of the P0339 code is that sometimes the car will not start or stop the engine. The engine light is often on when the P0339 code is stored. Your car could also be in limp mode if the code is stored in the engine control unit.
- The engine does not start
- The engine dies while driving
- Check Engine light
- Limp mode
- Low performance
- RPM meter at your dashboard doesn’t go up when cranking the engine
The most common reason for this error code is actually internal damage in the crankshaft position sensor, but there are several reasons for this error code and I recommend to diagnose the problem carefully before replacing any parts.
- Faulty or damaged crankshaft position sensor (most common)
- Faulty or damaged trigger wheel (harmonic balancer, flywheel, an internal wheel on the crankshaft)
- Wiring issue between the crankshaft sensor and engine control unit, shorted or open circuit
- Faulty connector to the crankshaft sensor, corrosion
- Faulty engine control unit (rare)
NOTE: The P0339 could also be triggered if your car had a low voltage from the car battery. If you know that your car had a low voltage when the error code occurred, charge or replace the car battery.
- Check if there are any external damages to the crankshaft sensor
- Clean the connector to the crankshaft sensor
- Check or measure the wirings between the ECM and crankshaft sensor
- Replace the crankshaft sensor if you get faulty results.
- Check or replace trigger wheel if damaged
- Replace engine control unit if faulty
- Charge your car battery or replace the battery
P0339 Troubleshooting Table
|Code||Description||Common Causes||Possible Solutions|
|P0339||Crankshaft Position Sensor 'A' Circuit - Intermittent||Faulty/Damaged Crankshaft position sensor ( Most common )
Faulty/Damaged Trigger Wheel ( Harmonic balancer, flywheel, an internal wheel on the crankshaft )
Wiring issue between the crankshaft sensor and engine control unit, shorted or open circuit
Faulty connector to the crankshaft sensor, corrosion
Faulty Engine control unit ( In Rare Cases )
|Check if there are any external damages to the crankshaft sensor
Clean the connector to the crankshaft sensor
Check/Measure the wirings between the ECM and crankshaft sensor
Replace Crankshaft sensor if faulty results.
Check/Replace Trigger wheel if damaged
Replace Engine control unit is faulty
Charge your car battery or replace the battery
How to diagnose the P0339 code
This is how an experienced automotive technician would diagnose the P0339 code. You may need some special tools to complete this diagnostic procedure, but you can review it to get an idea of how to do it. Always connect a car battery charger when performing diagnostics on your vehicle. A low voltage can lead to false results and even damage your ECUs.
- Connect an OBD2 code scanner and check the error code P0339
- Check the live data for “engine RPM”, start the engine and see if the speed increases or not. If you do not get a result, you should continue with the next step. If you get results, the error code may be intermittent and should be tested again if the car does not start.
- Visually inspect the crankshaft sensor and trigger wheel. Unplug the connector and check for corrosion.
- Measure the ohmic values inside the crankshaft position sensor with a multimeter. If you get no results, that means there is an open circuit inside the sensor. Replace the crankshaft position sensor. Check the repair manual for the correct ohm result. If you get the correct value, measure the ohmic values from the engine control unit connector with the sensor plugged in. If you do not get any results here, you probably have an open circuit in the wires.
- If the sensor seems to be OK, check the signal from the sensor with an oscilloscope (advanced only). Then check the signal on the motor control module connector and see if you get the same results. If they’re not the same results, it means you have faulty wiring.
- If all the results are OK and checked carefully, replace the crankshaft position sensor, as it may be an intermittent fault. If the sensor has received the correct distance, you have replaced it and checked the wiring, and you still receive the same error code. You may have a faulty engine control unit.
Recommended Tools to Fix P0339
To Read the Trouble code memory: FOXWELL NT301 Scan Tool. For basic settings and adaptions and to read other systems than the engine control unit, you may need a more advanced OBD2 code reader
Car Battery charger: NOCO Genius G3500 6V/12V Smart Battery Charger
Multimeter to measure the crankshaft sensor/wirings: AstroAI 6000 Counts Volt Meter Manual and Auto-Ranging
If you have further questions about the P0339 code, please comment below and I will answer your question as soon as possible. If you have further questions about the car, feel free to ask us on our homepage.