The Volkswagen Eos utilizes a crankshaft position sensor in order to regulate the engine timing. This sensor uses a reluctor to gauge the position of the crank. When the Eos’s ECM determines that there is an issue with the signal coming from this sensor, it’ll throw the P0335 trouble code.
P0335 Symptoms: Volkswagen Eos
Depending on the model year and engine of any vehicle the job of the crankshaft sensor is going to change.It’s either going to provide info to the ECM to keep the vehicle from misfiring. Or, it’ll provide necessary data to keep the engine timing in order.
Depending on whether or not the engine timing is dependent on the crank sensor is going to determine whether the symptoms of P0335 are going to be:
- Vehicle won’t start at all (timing dependent)
- Rough running motor
Often, if the crankshaft sensor or wiring itself is bad, there won’t be any RPM reading form the tachometer.
Eos P0335 Causes
Most of the time, the crankshaft sensor is going to be the cause of P0335, or the wiring will be at fault. There are other causes as well.There’s more on that directly below.
Bad Crank Sensor
The crankshaft sensor is often the reason that P0335 is thrown. They aren’t very expensive, but they can be difficult to get to in order to service them. If you think you’re up to the challenge (and know how to use a volt meter) this guide from doityourself.com will show you exactly how to test the sensor.
The crank sensor operates by scanning a “reluctor wheel”. This wheel can become damaged over time and will no longer give a proper reading to the ECM.
One of the most common symptoms of a bad reluctor ring is going to be a rattling sound. If the engine still runs, you will hear it. This means that it has been damaged, and no longer seated properly.
If you don’t hear a rattle, the ring could have broken or missing teeth. This will cause the vehicle to not get a good reading from the crank sensor.
Due to the location of the crankshaft position sensor, it is prone to damage. Start by inspecting the wiring harness between the firewall and crank sensor for any obvious damage. After that it would be prudent to look at the wiring harness plug at the sensor itself.
This YouTube video shows exactly how to test the wiring integrity.
Less Likely Reasons
Most of the time, the reasons outlined above are going to be the problem. But, not always. Here are some issues that are (not quite as) known to cause P0335 in the Eos
Timing Belt/Chain– It is possible that a vehicle that has jumped timing is throwing the code. Here’s more on diagnosing a bad timing chainfrom this site.
PCM/ECM– When the vehicle’s ECM goes bad, it can throw false trouble codes. This is definitely not the place to start, but is worth looking at if nothing else seems to be wrong. Symptoms of a bad ECM (Autoblog).
Good luck determining what is causing P0335 in your Eos. If you feel like there is anything you would like to add, please leave a comment below.