This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.
P0339 is an OBD-II Code that refers to Crankshaft Position Sensor A Circuit Intermittent
A P0339 code is caused by an ECM (Engine Control Module) receiving a signal that there is a problem with the crankshaft position sensor A circuit. Usually the parameters in the PCM (Powertrain Control Module) will be in range indicating that it's intermittent. When this happens, the engine control module begins to emit an 'Intermittent' code and the Check Engine Light (CEL) will illuminate.
Common causes for this code include:
- The crankshaft position sensor is damaged.
- Connectors on the sensor have been damaged.
- Wiring harness damage to the sensor
- Missing teeth or broken reluctor rings
- Timing belt damage caused by a broken timing belt wrapping around the sensor system
- PCM Failed (rare)
The symptoms of a P0339 code are:
- The engine may not start
- Check Engine Light is on
- Engine misfires
- Random loss of power
- Varying RPMs or stalling
- Or even no symptoms
- Bad Fuel Economy
To diagnose a P0339 DTC code, a technician would:
- Scan for codes in the ECM and look at the freeze frame data for failure.
- Perform a visual inspection of the wiring and connectors related to Crankshaft Position Sensor, or replace them if necessary.
- Look for broken teeth on reluctor rings to see if the timing belt is damaged.
- Remove and inspect the timing belt (if installed) for damage such as broken teeth, loose sections, missing teeth etc.
- This code will likely set in range parameters according to freeze frame data due to its intermittent nature
The following are some of the most common mistakes that a technician may make when diagnosing a P0339 code:
- Not checking for faults with Camshaft Position Sensor
- Not performing a visual inspection of the timing belt or broken teeth on reluctor rings.
- Not using freeze frame data correctly when diagnosing hard codes.
- Forgetting to turn off all unnecessary accessories before cranking over an engine with no start, which is needed to check if the PCM is commanding spark or injection pulses.
- Trying to re-set DTCs without doing any diagnosis first
How serious is this?
A P0339 code is considered a non-critical code. This means that the vehicle will continue to operate but will require repair. However, the engine may misfire or stall when this code is present which can increase the risk of a crash.
What repairs can fix the code?
The following are solutions that may fix this problem:
- Inspect and replace damaged components, connectors, wiring harnesses as needed
- Replace crankshaft position sensor
- Replace PCM if necessary
- Replacing a timing belt, reluctor rings or other components due to a broken timing belt
- Check that there is no Oil Leaks that can corrosion to wiring
A P0339 is related to and may be accompanied by the following codes:
In conclusion, the P0339 code is a generic trouble code that means the computer has detected a problem with the engine's crankshaft position sensor A circuit. This code is considered a non-critical code but can have effects such as misfiring, stalling and bad fuel economy. The best way to diagnose this code would be to check for codes in the ECM using a scan tool and perform a visual inspection of all related components.