What Does Code P0340 Mean?
- P0340 definition: Camshaft Position Sensor Circuit Malfunction
- Issue Severity: SEVERE – Stop driving immediately
- Repair Urgency: Fix this code immediately (same-day if possible) to avoid internal engine damage.
- Diagnosis: The vehicle may be difficult to start and the driver may also experience a lack of power when driving. It is possible for more damage to occur inside the engine of the vehicle if disregarded for an extended time period. It is extremely important to repair code P0340 as soon as possible.
The camshaft position sensor located in the internal combustion engine monitors the position and rotational speed of the camshaft. It works hand in hand with the reluctor ring that creates a square wave voltage signal that the ECM interprets as the crankshaft position. The ECM uses this information to control ignition spark and fuel injector timing. When the trouble code P0340 is set, the ignition spark and fuel injector timing fail due to the engine not knowing when to fire these components.
P0340 Causes
There are many potential causes of code P0340. It is difficult to determine which of these is the source of the problem without specialized knowledge.
- A defective camshaft position sensor.
- Damaged or dirty reluctor ring on the camshaft
- Defective, corroded, shorted camshaft position sensor circuit wiring
- Defective, corroded, shorted camshaft position sensor circuit connector
- A faulty crankshaft position sensor
- Stretched or misaligned timing components
- ECM software update needed
- Faulty ECM
We recommend reading our guide on how much it can cost to replace a defective camshaft position sensor if you’re thinking about hiring a professional.
P0340 Symptoms
- Check Engine Light
- The vehicle will not start – may be difficult to start
- Rough idle/stall
- Vehicle engine misfire
- Loss of power when driving
In many cases, there may be no noticeable issues with your vehicle.
How Do I Fix Code P0340?
With a camshaft position sensor fault, the first step is to get it diagnosed to figure out what is causing the problem.
If your vehicle has this fault and you’re not comfortable diagnosing this issue at home, we recommend finding a RepairPal certified shop nearby to pinpoint the problem and give an accurate estimate for repairs.
These shops can not only help you figure out what’s going wrong before you waste time and money on the wrong parts, but they also offer a minimum 12-month, 12,000-mile warranty and stand behind all their estimates with guaranteed fair pricing.
> Find a RepairPal Certified Shop Near You
How Much Does It Cost to Fix Code P0340?
P0340 can be caused by anything from damaged wiring to a bad sensor to a faulty ECM. It’s impossible to give an accurate estimate without properly diagnosing the issue first.
If you take your car to a shop for diagnosis, most shops will start with an hour of “diag time” (the time spent in labor diagnosing your specific issue). Depending on the shop’s labor rate, this typically costs somewhere between $75-$150. Many, if not most, shops will apply this diagnosis fee to any required repairs if you have them perform the repairs for you. From there, a shop will be able to give you an accurate estimate for repairs to fix your P0340 code.
Possible Repair Costs for P0340
For error code P0340, one or more of the below repairs may be needed to solve the underlying issue. For each possible repair, the estimated cost of repair includes the cost of the relevant parts and the cost of labor required to make the repair.
- Camshaft position sensor $120-$300
- Crankshaft position sensor $190-$250
- ECM $1000-$1200
- Timing chain or belt replacement $200-$1000
DIY Steps to Diagnose Code P0340
Engine code P0340 could be caused by a number of things, including a bad sensor, damaged wiring, or a faulty ECM. If you’d like to try to fix code P0340 at home without throwing money at parts, you’ll want to follow the steps below for proper diagnosis. Keep in mind this is an intermediate-level diagnosis and repair and not recommended for beginners. Diagnosis requires more specialized equipment beyond what the FIXD Sensor can provide and it can be a time and labor-intensive process for inexperienced DIYers.
DIY difficulty level: Intermediate
This repair requires mechanical knowledge and is not recommended for beginners.
Tools/parts needed (our top picks from Amazon):
- FIXD
- Multimeter
- Basic Hand Tools
STEP 1: INSPECT THE CAMSHAFT POSITION SENSOR WIRING.
Visually inspect the camshaft position sensor wiring in search of corroded, broken, or frayed wiring.
STEP 2: INSPECT THE CAMSHAFT POSITION SENSOR CONNECTOR.
Visually inspect the camshaft position sensor connector in search of corroded or broken connectors.
STEP 3: USE FIXD TO ENSURE NO OTHER ENGINE CODES ARE PRESENT.
Use FIXD to scan your vehicle to verify P0340 is the only code present. Make any other repairs (if other codes are present) to make sure that other codes are not sources of the trouble code P0340. Click here to see what else the FIXD app has to offer.
STEP 4: CHECK THE CAMSHAFT POSITION SENSOR.
Check your camshaft position sensor’s voltage, ground, and signal readings with a multimeter. Check out this video for a visual reference on how to check it using your multimeter.
STEP 5: CHECK THE RELUCTOR RING.
If you find that the camshaft position sensor fails to produce a voltage or a signal, remove it and check the reluctor ring for damage, debris, or misalignment. If the reluctor ring appears in good condition, replace the camshaft position sensor.
STEP 6: CHECK THE CRANKSHAFT POSITION SENSOR.
If the concern persists, perform the same test as you did on the camshaft position sensor to the crankshaft position sensor and its circuits. If it fails the tests, replace it.
STEP 7: CHECK CONTINUITY.
If the concern still persists, perform a continuity test on the camshaft and crankshaft position sensor circuits between the respective sensors and the ECM. Repair any faults you discover.
If these steps do not resolve your Check Engine Light, you may need to visit a mechanic because there may be internal issues with the ECM, stretched or damaged timing components, or the possibility of an ECM software update that may resolve the concern.
Common P0340 Diagnosis Mistakes
Replacing the camshaft position sensor without checking the wiring, connector, or reluctor ring beforehand. There may also be the possibility of neglecting a misfire or timing error.
Still Need Help Fixing Code P0340?
If you’ve followed the steps above and are still experiencing check engine code P0340, please contact the FIXD Mechanic Hotline if you’re a FIXD Premium subscriber or find a RepairPal certified shop near you to get the right repairs at a fair price.
- Get Your Code Fixed Fast
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Fixed It But The Check Engine Light Is Still On?
Check engine light sometimes need to be reset manually, check out our article:
How to Reset Your Check Engine Light | 4 Ways To Clear It (With or Without a Scanner)
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