Honda Check Engine Code
P0340 on Honda
Camshaft Position Sensor A Circuit Malfunction (Bank 1 or Single Sensor)
Also covers: Acura
P0340 on Honda: what makes it different
P0340 — Camshaft Position Sensor Circuit Malfunction (Bank 1, Sensor A) — is a well-documented issue on Honda vehicles, particularly those powered by the K-series and J-series engines. Honda's camshaft position sensors are integrated closely with the distributor-less ignition and VTEC systems, meaning a failing sensor can affect both spark timing and VTEC engagement simultaneously. Honda owners frequently report P0340 alongside no-start conditions, stalling, and rough running because the PCM relies heavily on camshaft position input for sequential fuel injection timing.
Most-affected engines
- K24A/K24Z I4 2.4L (CR-V, Accord, Element, TSX)
- K20A/K20Z I4 2.0L (Civic Si, RSX)
- J35A/J35Z V6 3.5L (Odyssey, Pilot, Ridgeline — Bank 1)
- R18A/R20A I4 (Civic 2006–2015)
- F22B/F23A I4 (Accord 1998–2002)
Common model years: 2003–2018
Most likely cause on Honda
Failed or intermittently failing camshaft position sensor on Bank 1 due to heat cycling and connector corrosion, especially on K-series engines with higher mileage.
Known Honda engine-family issues
High-mileage K24 engines (typically above 150,000 miles) are known to develop timing chain stretch, which can cause the camshaft position signal to arrive slightly out of phase relative to the crankshaft signal. This can trigger P0340 or related camshaft correlation codes. On J35-series V6 engines used in Odyssey and Pilot, the Bank 1 camshaft sensor is located in a position where it is exposed to engine heat and oil mist from PCV routing, accelerating seal and connector degradation. Honda's cam cover gaskets on K-series engines are known to seep oil over time, and oil contamination of the sensor body is a frequent finding on vehicles with deferred valve cover gasket replacement.
Honda-specific causes (most common first)
- Camshaft position sensor failure from long-term heat exposure in Honda's tightly packaged engine bay
- Corroded or backed-out terminal in the CMP sensor connector — Honda's multi-pin connectors are prone to corrosion in humid climates
- Damaged or chafed wiring harness where it routes near the cam cover or timing chain area
- Reluctor ring (cam trigger wheel) damage from timing chain stretch, particularly on high-mileage K24 engines
- Timing chain wear causing cam-to-crank correlation error that triggers P0340 alongside P0016 or P0017
- Oil contamination at the sensor base from a leaking cam cover gasket allowing oil into the sensor bore
Honda-specific diagnostic tip
Before replacing the camshaft position sensor on a Honda, unplug the sensor connector and inspect every terminal pin carefully with a flashlight. Honda's connectors use a lock-tab design that can allow individual terminals to back out slightly, creating an intermittent open circuit that triggers P0340 only under vibration or heat. Use a fine pick to verify each terminal is fully seated and check for green corrosion. Also check reference voltage (5V), ground, and signal wire continuity at the connector with a multimeter before purchasing a new sensor — the wiring is the culprit nearly as often as the sensor itself on Honda applications.
Symptoms drivers report
- Check engine light
- Hard starting or no start
- Stalling
- Loss of power
- Erratic idle
Typical repair cost on Honda
Most Honda owners fix P0340 for between $60 and $450, depending on which underlying cause turns out to be at fault. Start with the most-likely cause for your vehicle — Failed or intermittently failing camshaft position sensor on Bank 1 due to heat cycling and connector corrosion, especially on K-series engines with higher mileage. — before throwing parts at it.
Honda P0340 FAQ
Will a P0340 cause my Honda to not start?
Yes, it can. The PCM uses the camshaft position signal to determine the correct cylinder for sequential fuel injection. If the signal is completely absent, the PCM may default to a non-sequential or batch-fire mode that causes hard starting or a no-start condition. Intermittent P0340 faults often cause stalling at idle or during warm-up before fully disabling the engine.
Can timing chain wear cause P0340 on my Honda K24?
Yes. On higher-mileage K24 engines, timing chain stretch moves the cam sprocket position relative to the crankshaft, which can confuse the PCM enough to set P0340 or camshaft correlation codes. If you also have codes related to VTEC system malfunction or variable cam timing, inspect the timing chain and tensioner condition before simply replacing the sensor.
Is it safe to drive my Honda with P0340 active?
It depends on severity. If the code is stored but the car starts and runs normally, you may be able to drive short distances cautiously to get to a shop. However, if the car is stalling, hesitating, or misfiring, do not continue driving — an unexpected stall at highway speed or in traffic is a safety risk. P0340 should be diagnosed and repaired promptly.
Related codes
Drive a different make? See the general P0340 guide for cross-vehicle causes and symptoms.
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Most common fix for P0340:
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