P0340 Code on Nissan: Camshaft Position Sensor Causes, Recalls, and Repair Cost

This guide explains how the camshaft sensor works on a Nissan, what sets P0340, the causes in the order to check them, the Nissan recalls and service bulletins for Altima, Sentra, Maxima, Frontier and others, repair costs by model, and whether it is safe to drive. Recall details come from NHTSA records and the diagnostic steps from Nissan service manual procedures.

For another Nissan code with a known fix, see our P1148 Nissan guide. And our free VIN decoder confirms your exact model, engine and build date, which decides which recall or bulletin applies.

What Does P0340 Mean on a Nissan?

When the Engine Computer Sets P0340

According to Nissan’s service manual, P0340 sets when:

• “The cylinder No. signal is not sent to ECM for the first few seconds during engine cranking.”
• “The cylinder No. signal is not sent to ECM during engine running.”
• “The cylinder No. signal is not in the normal pattern during engine running.”

Nissan’s confirmation test requires battery voltage above 10.5 volts with the key on, which is one reason a weak battery can set or mimic this code.

P0340 Symptoms on a Nissan

• Check engine light (Service Engine Soon) with P0340 stored.
• Hard starting when the engine is warm, with cranking longer than 3 seconds. Nissan bulletin NTB04-063 describes this on several 2003 to 2005 models.
• No start or reduced power.
• Stalling. Nissan recall 03V-455 warns that a faulty cam or crank sensor can cause the engine “to stop running without warning during vehicle operation.”

Common Causes of P0340 (Check in This Order)

Weak Battery or Starting System

Nissan lists a “dead (weak) battery,” the starter motor and the starting system circuit as possible causes. Low cranking voltage can stop the sensor signal from being read correctly. Test the battery and charging system first, because it costs nothing.

Connector or Wiring

Nissan’s diagnosis checks the sensor connector, its ground, its power supply and the signal wire to the engine computer for an open or short circuit. Look for bent pins, a loose lock tab, corrosion or chafed wires. Nissan also says that if code P0643, a sensor power supply fault, is stored too, diagnose that one first.

Debris on the Sensor or Camshaft Signal Plate

Nissan’s procedure includes removing the sensor to check it for chipping and checking for “accumulation of debris to the signal plate of camshaft rear end” and a “chipping signal plate.” RepairPal also advises fixing any oil or coolant leaks that could ruin a new sensor.

Failed Camshaft Position Sensor

If the power, ground and signal circuits test good, the sensor itself is the likely fault. Make sure you replace the correct bank: on V6 engines, bank 1 and bank 2 sensors can use different part numbers. For example, Nissan bulletin NTB04-063 lists 23731-6J906 for bank 1 and 23731-AL616 for bank 2 on the models it covers.

Crankshaft Position Sensor

The camshaft and crankshaft sensors work together, so a crank sensor fault can appear alongside P0340. If P0335 is stored too, test the crank sensor.

Timing Chain Wear

RepairPal notes that a camshaft sensor code can be triggered by a worn timing chain. Nissan bulletin NTB09-128a covers a whining noise from the timing chain area on 2005 to 2010 Frontier, Xterra and Pathfinder models with the 4.0L engine, but it does not list any trouble codes. Suspect the chain only if the sensor and wiring test good and you hear a whine or rattle.

Nissan Recalls and Bulletins for P0340

This is the most important part for older Nissans. Several safety recalls covered cam and crank sensor problems that could stall the engine. Safety recall repairs are free.

NHTSA’s VIN lookup does not show safety recalls that are more than 15 years old. If you own a 2000 to 2007 Nissan, call Nissan Consumer Affairs at 1-800-647-7261 to ask whether a recall is still open on your VIN.

Related Recall: 2004 to 2006 Nissan Trucks and SUVs

Recall 10V-517 covers about 747,000 2004 to 2006 Armada, Titan and Infiniti QX56 and 2005 to 2006 Frontier, Pathfinder and Xterra vehicles. Oxidized contacts in the engine computer relay could cause engine stalling, and the fix is a new relay. It does not name P0340, but if your truck stalls, it is worth checking.

P0340 on the Nissan Frontier, Pathfinder and Xterra

We found no Nissan bulletin that names P0340 for the 2005 and newer Frontier, Pathfinder or Xterra with the 4.0L engine. On these trucks, work through the standard order: battery, connectors and wiring, then the sensor. On the V6, confirm whether the code is bank 1 (P0340) or bank 2 (P0345) before buying a part, and consider an original-equipment sensor. If the code returns after a new sensor, test the crank sensor and wiring, and listen for timing chain noise.

How Much Does It Cost to Fix P0340?

These are RepairPal estimates checked in September 2026, before taxes and fees. A safety recall repair is free.

How to Diagnose P0340 Yourself

This order follows Nissan’s service manual procedure. Use your factory service information for exact test values.

• Check the battery and starting system. Nissan’s test needs more than 10.5 volts with the key on.
• Check open recalls and bulletins by VIN, or call Nissan for older vehicles.
• Inspect the sensor connector for bent pins, corrosion and a secure lock, and check the ground connection.
• Check the sensor power supply with the key on and the connector unplugged.
• Check the ground and signal wires to the engine computer for opens and shorts.
• Remove the sensor and check it for chips or debris, and check the camshaft signal plate.
• Replace the sensor for the correct bank, then clear the code and confirm it does not return.
• If it returns, test the crank sensor and wiring and look for timing chain or mechanical problems.

Can You Drive With a P0340 Code?

It is not a good idea. Some cars run almost normally with P0340, but Nissan safety recalls for faulty cam and crank sensors describe engines that stop running without warning while driving, which can cause a crash. Until you know the cause, avoid highway driving and heavy traffic, and get it checked promptly. If the engine stalls or will not restart, have it towed.

P0340 vs Related Nissan Codes

• P0335: crankshaft position sensor (POS) circuit. Often appears together with P0340.
• P0345: the same camshaft sensor fault on bank 2 of a V6.
• P0341: camshaft position sensor “A” circuit range or performance, a signal that is present but out of range.
• P0011 and P0021: intake valve timing control, bank 1 and bank 2.
• P0643: sensor power supply circuit. Nissan says to diagnose it before P0340.

The Bottom Line

P0340 on a Nissan points to the camshaft sensor signal, and it can affect how safely the engine runs. Check your VIN for recalls, test the battery and wiring before buying parts, replace the sensor for the correct bank, and do not ignore stalling.

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Morgan Reyes

Morgan Reyes is the Lead Automotive Journalist and EV Analyst at Next Car Review. Specializing in mechanical systems and next-generation electric vehicles, Morgan breaks down complex automotive data, legacy matchups, and upcoming model previews into practical insights for car buyers.