OBD codes / P0340 / Nissan Altima
P0340 on a Nissan Altima
Camshaft Position Sensor A Circuit Malfunction (Bank 1)
QR25 and VQ35 Altima.
What P0340 usually means on a Altima
P0340 indicates a problem in the Altima's camshaft position sensor circuit, which the ECU uses for timing and fuel/spark synchronization. On these engines it can cause hard starting, stalling, or intermittent no-starts, sometimes when the engine is hot. The sensor itself or its connector and wiring is the typical fault. It is a common, relatively inexpensive sensor to replace once confirmed.
Most likely causes on this model
- Failed camshaft position sensor
Heat-related sensor failure is common and can cause hot-start problems on these engines.
- Wiring or connector fault
A chafed or corroded connector interrupts the signal.
- Crank/cam correlation issue
Timing-chain stretch on high-mileage engines can throw off cam timing and set the code.
What it costs on a Altima
The cam sensor is a modest part and generally accessible on the Altima, keeping this among the cheaper sensor repairs. Inspect the connector and wiring before replacing the sensor. If a stretched timing chain is behind it, the repair becomes far more involved.
Year, engine and mileage change the answer. Get a diagnosis for your Altima — it weighs these causes against your exact configuration and real complaint data.
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Related symptoms
Nissan Altima problems & recalls by year
Based on widely reported patterns for this model; individual causes vary by year, engine and history. Generic P0340 behavior is covered on the main P0340 page. Confirm with a scan tool before buying parts.