When the Check Engine Light comes on, your immediate reaction is to panic and worry about what needs to be fixed. In some cases, there’s no reason for the alarm, while other times, it can be serious. One of the more serious issues is the P0340 code. This trouble code indicates a problem that needs to be looked at immediately.
In this guide, we show you what the P0340 code means, show you the symptoms and reveal the top causes. We also look at what might fix it and show you how to troubleshoot the problem. At the end of the article, you’ll find a few top-asked questions to explain the trouble code further.
Code P0340 Definition
P0340 – Camshaft Position Sensor Circuit Malfunction
What Does the P0340 Code Mean?
The P0340 trouble code reveals a problem with the camshaft position sensor. This sensor calculates the rotational speed of the camshaft and shows its position. This information is sent to the Engine Control Module (ECM), so the ignition spark and fuel injection timing can be adjusted.
If the signal to or from the sensor is broken, the ECM stores this trouble code. There will also be an issue with the ignition spark or fuel injector timing as a result of the misinformation.
What Are The Symptoms Of P0340?
The most obvious symptom is the Check Engine Light. However, the P0340 can also affect the fuel injection system or the ignition system, causing other symptoms. Here are some of the most common.
- Check Engine Light
- Vehicle doesn’t start or has difficulty
- Rough idle
- Stalling engine
- Loss of power/lack of acceleration
- Increased fuel consumption
What Are The Causes of P0340?
Because the P0340 DTC has everything to do with the camshaft position sensor, it’s safe to assume that this part might be to blame. However, it’s not the only cause of the fault. Here are the most common causes.
- Defective camshaft position sensor
- Dirty or damaged camshaft reluctor ring
- Defective or corroded wiring
- Malfunctioning timing chain or belt
- Faulty ECM (update needed)
How Serious is the P0340 Code?
Severe – Your vehicle may not start, or it can become difficult to start. For this reason alone, you would need to have it looked at right away.
Even if you get the vehicle started, you could notice a lack of power, especially when you try to accelerate. If you attempt to pull out in traffic without any power, an accident could occur.
Furthermore, it’s possible to cause more damage to the engine by neglecting this repair. That’s why it’s best to diagnose and repair the P0340 trouble code as soon as you can.
How Do I Fix the P0340 Code?
Based on the most probable causes, it isn’t difficult to determine what fixes might be required. However, you should always walk through the diagnostic steps to determine the fault before fixing anything. We have those listed below.
In the meantime, these are some of the most popular repairs.
- Repair/replace camshaft position sensor wiring
- Repair/replace camshaft position sensor connector
- Replace camshaft position sensor
- Replace camshaft reluctor ring
- Replace timing belt or chain
- Update/replace ECM (unlikely)
Common P0340 Diagnosis Mistakes
Because the trouble code has to do with the camshaft position sensor, technicians and home mechanics always want to rush to replace this part. However, there are many other probable causes that won’t require a sensor replacement.
Most importantly, you should check the connection and the wiring. If any of the electrical connections could be to blame, that should be dealt with first.
How to Diagnose the P0340 Trouble Code?
You don’t have to be a professional technician to diagnose this trouble code. All you need are the right tools and a little bit of patience. We’ve outlined how we would handle this problem and you can follow the steps until they become too difficult for you.
- Connect your compatible code scanner to read all of the DTCs.
- Start by deleting the code to see if it returns.
- Trace all of the wiring coming to and from the camshaft position sensor. If you notice any of the wiring to be defective or corroded, you should replace it. It’s also wise to look over any connectors.
- Read your car’s service manual to get the exact procedure for testing the camshaft position sensor. You need to find the correct ohm value, which can be complicated procedures if you aren’t sure what you are looking at.
- Some people that don’t have the equipment to do the testing replace the sensor to see if it fixes the problem. It doesn’t normally cost a lot to replace it, so this might be the avenue you take.
- If the sensor doesn’t fix the problem and the wiring isn’t to blame, the computer may need an update.
- Inspect the timing belt or chain to ensure there’s no problem there that needs to be dealt with. This isn’t normally the problem with the code because it’s related to circuitry, but it’s worth ruling out at this time.
At this point, we recommend reaching out to a qualified mechanic for more support. You don’t want to cause more damage than what you are already dealing with.
How Much Does It Cost To Fix Code P0340?
Based on the possible fixes we’ve outlined, we can also estimate some of the repair costs. These averages include both the parts and the labor. If you can perform the fix yourself, you may spend less money.
- Repair/replace camshaft position sensor wiring – $50 to $550
- Repair/replace camshaft position sensor connector – $50 to $550
- Replace camshaft position sensor – $125 to $375
- Replace camshaft reluctor ring – $1,000+
- Replace timing belt or chain – $200 to $875
- Update/replace ECM – $500 to $2,500
Also, the cost of repair depends on what type of vehicle you drive and where you live.
A Mechanic’s Tips About The P0340 Code
It’s not easy to figure out the cause of the P0340 code. This is one of the DTCs that can be a real pain. For this reason, many mechanics and drivers choose to replace the sensor if no other obvious causes can be found.
For the cost of a new sensor, this is often the best step. Most of the time, it is the cause of the problem, so you may not have to do anything else.
Is code P0340 serious?
Yes, if you have trouble getting the car started, it could fail at any time. Additionally, there could be performance issues while you are driving, which could cause an accident in heavy traffic. You also don’t want to promote any further damage by neglecting to have the issue fixed.
How do I fix the error code P0340?
It’s important to start with a thorough diagnosis. Once you determine what’s wrong, you can repair the problem. In most cases, there’s a bad wire, defective connector, failing sensor, a malfunctioning chain or belt, or the ECM needs to be updated. It could also be a malfunction of the reluctor ring, which can be expensive to repair.
Can I drive with a P0340 code?
We don’t recommend driving once the P0340 code is discovered. This problem can cause trouble starting the car, leaving you in a dangerous situation if you aren’t at home. If the car does run, you may have trouble accelerating, which is also dangerous.
Can a bad crankshaft angle sensor cause misfires?
When the crankshaft sensor fails, the engine can misfire because the fuel injection timing would be off. Eventually, the car may stall and fail to restart. This problem can also lead to a rough idle and backfiring. The earlier you have it repaired, the better it will be for the engine.
Will P0340 cause a no start?
It can cause the car to have trouble starting. Because P0340 reveals that there’s a problem with the camshaft position sensor, both the fuel injection and ignition systems can struggle. You may notice performance issues, such as a lack of acceleration or a rough idle if the car is running.
As mechanics, we can’t stress enough how important it is to get your vehicle looked at when the Check Engine Light comes on. With the P0340 trouble code, prompt action can keep your vehicle from having more issues. If you neglect the problem, you may find yourself with a car that no longer starts. That would be quite inconvenient, especially if you are late for work.
Most of the fixes are simple to resolve and won’t cost a lot. It’s the diagnosis of the P0340 DTC that can often take the longest. If you have some basic mechanical skills, you may be able to fix the problem yourself, saving you some money.