P0340 on a 2010 Honda Accord signals a problem with the camshaft position sensor circuit. In practical terms, the engine control module is seeing a signal that is missing or out of spec, which can lead to starting issues, misfires, or the check engine light coming on.
What P0340 means for your Accord
The camshaft position sensor (CPS) tells the engine computer where the camshaft is in its rotation so that ignition timing and fuel injection can be synchronized. When the CPS circuit malfunctions, the PCM may not be able to time the spark or fuel correctly, triggering P0340.
Symptoms to watch for
If P0340 is active, you may notice one or more of the following signs on a 2010 Accord.
- Engine runs roughly or misfires, especially at idle or during acceleration
- Difficulty starting or a no-start condition
- Intermittent stalling or reduced engine performance
- Check Engine Light (CEL) illuminated, often with other codes
- Poor acceleration or reduced power when pulling away
Not every car with P0340 will show all of these symptoms, but the pattern is common enough to warrant inspection of the CPS system if you notice any of them.
Likely causes
Several issues can trigger a P0340 on a 2010 Honda Accord. Common culprits include:
- Faulty camshaft position sensor or its wiring
- Damaged or corroded sensor connector or wiring harness
- Oil contamination around the sensor or near the cam gear
- Timing chain issues or improper timing alignment
- PCM/engine computer software issues or a loose power/ground connection
More rarely, a P0340 can be caused by an unrelated bad sensor or a PCM glitch. A proper diagnostic can distinguish between a sensor replacement and a wiring/PCM issue.
Diagnosis steps and potential fixes
Here is a practical order of steps technicians typically follow to confirm P0340 and fix the problem on a 2010 Accord.
- Scan for codes and record any related codes, such as P0300 (random misfire) or P0010 (timing).
- Inspect the camshaft position sensor and its wiring for damage, oil leaks, or corrosion at the connector.
- Check the sensor’s electrical resistance and voltage signal with a multimeter/scan tool; compare live data to spec.
- Inspect for oil leaks or contamination around the CPS and replace gaskets if needed.
- Replace the camshaft position sensor if the electrical tests indicate a fault.
- Inspect timing chain and related components (tensioner, guides) if the timing reference appears off.
- Reassemble, clear codes, and test drive to ensure the problem is resolved. If codes return, re-check wiring and possibly the PCM if sensor and wiring are fine.
Costs can vary by engine variant and shop rates. Replacing the CPS itself often ranges from about $50 to $150 for parts, with labor adding to the total if a mechanic performs the service. In some cases, fixing wiring or connectors may be cheaper, while timing-related issues could require more extensive (and costly) work.
Other considerations for the 2010 Honda Accord
Because the 2010 Accord has multiple engine options, the exact CPS location and service procedure can differ. The 4‑cylinder engine uses a CPS mounted near the timing chain on the cylinder head; the V6 layout is different but follows the same general principle. Always consult the vehicle’s service manual for the correct part number and torque specs.
Summary
P0340 on a 2010 Honda Accord points to a problem with the camshaft position sensor circuit, which can affect starting, idle, and power. Diagnosis centers on inspecting the CPS and wiring, testing the sensor signal, and addressing any timing issues. Replacement of the CPS and related wiring is a common fix, with costs varying by engine version and labor rates. If you experience symptoms, have the vehicle scanned, tested, and repaired by a qualified technician.