P0340 on Infiniti: How to Diagnose & Fix
Camshaft Position Sensor Circuit Malfunction
7 Infiniti models · 8 documented issues · 4 critical · $150-$5,000 repair
P0340 on Infiniti by model: symptoms, diagnosis and fix
The VQ37VHR engine can develop intermittent camshaft or crankshaft position sensor failures, causing hard starts, stalling, or reduced performance. Heat and age can degrade the sensors or their signal quality, and owners across Nissan/Infiniti VQ applications frequently report these failures as mileage increases.
Common Symptoms
- Check engine light
- Extended cranking or hard starting
- Engine stalling intermittently
- Reduced power or limp-like behavior
How to Fix
Diagnosis is done with a scan tool and live data to identify which sensor is dropping out, followed by checking connector condition and harness integrity. Repair involves replacing the failed camshaft or crankshaft position sensor with a quality OE-equivalent part and clearing codes; typical repair costs range from about $180-$450 depending on which sensor failed and labor access.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Walker Products 235-1386 crankshaft position sensorOEMWalker Products 235-1386
Confirm eBay vehicle compatibility and exact part number before purchase; it is not a cam sensor.
- OEM Infiniti M37 crankshaft position sensorOEM23731-JA10C
OE crank-sensor branch after P0335/signal diagnosis Fitment/availability: Fits 2011-2013 M37 VQ37VHR and mounts at the engine/transmission junction. Confirm VIN and that the crank signal—not a cam circuit, wiring or timing fault—is the f…
- Genuine Infiniti VQ37VHR camshaft position sensorOEM23731-EY00B
Cam-sensor branch after bank/sensor diagnosis Fitment/availability: Fits listed 2011-2013 M37 VQ37VHR; quantity two are used and sold individually.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
- TipIf one sensor fails at higher mileage, inspect the others and the connectors at the same time since heat exposure affects them similarly.
- TipAvoid cheap no-name sensors; many owners report repeat check-engine lights and drivability issues with low-cost replacements.
Sources for this issue (1)
The circuit boards inside the crankshaft and camshaft position sensors were built with improper solder joints — flux residue left during manufacturing accelerated heat-stress deformation of the solder. As the joint degrades the sensor signal drops out, most often once the engine bay is hot. The result is a Service Engine Soon light, a no-start, reduced engine power, or the engine simply cutting out without warning while driving. NHTSA campaign 03V455000 covers the defect and explicitly supersedes the earlier 01V357 campaign, because the replacement sensors installed under that first recall were themselves affected. Owner notification began December 22, 2003.
Common Symptoms
- Engine cranks but will not start when hot, starts fine when cool
- Engine stalls without warning while driving
- Service Engine Soon light with crank or cam sensor codes
- Reduced engine power or limp mode
- Intermittent rough running that worsens with heat
How to Fix
Verify with Infiniti by VIN that 03V455000 was performed, not merely the earlier 01V357 — cars repaired under the first campaign received defective replacement parts and need the work done again. Dealers replace the crank position sensor, camshaft position sensor(s), and in some cases the variable timing control sensors. On a car well past the recall window, the classic signature is a hot-restart failure: the engine cranks but will not fire after a short stop on a warm day, then starts fine once it cools. Do not throw a fuel pump at that symptom before testing the crank sensor signal — this is the single most common cause of the complaint on this engine.
Sources for this issue (1)
The FX35 commonly develops intermittent failures of the camshaft position sensors and sometimes the crankshaft position sensor, causing stalling, hard starts, or limp operation. Heat and age degrade the sensor electronics, and this issue is widely reported across Nissan/Infiniti VQ applications of the era.
Common Symptoms
- Check engine light
- Intermittent stalling
- Extended cranking before start
- Reduced power or limp mode
- Sudden no-start condition
How to Fix
Diagnosis is done by scanning for correlation or sensor circuit codes and monitoring live RPM/cam signals during crank and road test. Repair usually involves replacing one or both cam sensors and sometimes the crank sensor, preferably with OE-quality parts because low-cost sensors often cause repeat faults. Typical repair cost is about $150-$450 depending on how many sensors are replaced and labor rates.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Infiniti VQ35DE driver-side camshaft position sensorOEMInfiniti 23731-AL61D
Confirm VIN, bank/physical connector and original number; it is not the pas
- Genuine Infiniti VQ35DE passenger-side camshaft position sensorOEMInfiniti 23731-6J90D
Confirm VIN, bank/physical connector and original number; it
- Hitachi VQ35DE crankshaft position sensorOEMHitachi CPS0006
Confirm VIN, connector and physical position; AutoZone's
- Genuine Infiniti VQ35HR camshaft position sensorOEMInfiniti 23731-JA11B
Confirm VIN, bank/location and required quantity from the service diagram; the retailer's legacy part-description fie
- Genuine Infiniti VQ35HR crankshaft position sensorOEMInfiniti 23731-JA10C
Confirm VIN, connector and physical location; do not interchange it with the JA11B cam sensor.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
- TipReplace both bank cam sensors together if mileage is high, since the second sensor often fails soon after the first.
Sources for this issue (1)
The VQ35DE engine used in the M35 is known for intermittent camshaft and crankshaft position sensor failures. Heat and age can cause the sensors to send erratic signals, leading to hard starting, stalling, limp mode, or a check engine light.
Common Symptoms
- Check engine light
- Intermittent stalling
- Extended cranking or no-start
- Reduced power or limp mode
- Rough running after warm-up
How to Fix
Scan for stored fault codes and monitor cam/crank synchronization data while checking harness condition near the sensors. Repair typically involves replacing the failed camshaft position sensor(s) and sometimes the crankshaft position sensor with quality parts, then clearing codes and confirming proper restart behavior. Using OEM-supplier sensors is strongly preferred because cheap sensors often cause repeat failures.
What you need to diagnose it
The repair instructions explicitly call for reading stored codes. Use a scanner that can read the named code families before choosing a repair.The recommended scanner supports these code families; confirm your exact year, model and module coverage before buying.
ANCEL AD310 Classic OBD-II Scanner
Read & clear engine (P) codes
$20–$40View
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
Reading and clearing the code is DIY work. Module replacement or reprogramming is not — most modules are VIN-programmed, so a new one does nothing until a shop codes it to your car. Check for an open recall or service bulletin before buying anything.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Walker Products 235-1150 position sensorOEMWalker Products 235-1150
Existing VQ35DE crank-position-sensor branch after exact OE cross and circuit diagnosis Fitment/availability: ShowMeTheParts research attached to the existing link matched Walker 235-1150 by M35 year/engine.
- Genuine Infiniti VQ35DE driver-side camshaft position sensorOEM23731-AL61D
Confirm model year, VQ35DE, side and VIN; do not use as the passenger-side sensor or on the VQ35HR.
- Genuine Infiniti VQ35DE passenger-side camshaft position sensorOEM23731-6J90D
Confirm VIN/side and do not substitute the driver-side AL61D or VQ35HR sensor.
- OEM 2009-2010 M35 VQ35HR camshaft position sensorOEM23731-JA11B superseding 23731-JA11A
VQ35HR cam-sensor branch after identifying the failed sensor position Fitment/availability: Fits 2009-2010 M35 VQ35HR; four are used and sold individually.
- OEM 2009-2010 M35 VQ35HR crankshaft position sensorOEM23731-JA10C
VQ35HR crank-sensor branch after P0335/signal diagnosis Fitment/availability: Fits 2009-2010 M35 VQ35HR and mounts at the passenger-side engine/transmission junction.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
- TipIf one cam sensor fails, many owners replace both cam sensors and the crank sensor together to avoid repeat breakdowns.
- TipClear codes only after confirming battery voltage is healthy, since weak voltage can complicate diagnosis.
Sources for this issue (1)
Camshaft and crankshaft position sensors are a well-known failure point on many Nissan and Infiniti vehicles of this era, including the FX45. Heat and age can cause intermittent signal loss, resulting in stalling, hard starting, limp operation, or a no-start condition.
Common Symptoms
- Intermittent stalling
- Extended cranking or no-start
- Check engine light
- Engine goes into fail-safe mode
- Sudden loss of power
How to Fix
Diagnosis is done by scanning for cam/crank correlation or sensor circuit faults and monitoring RPM/cam signals during cranking. Repair usually involves replacing the failed camshaft sensor(s) and/or crankshaft sensor with quality OEM-equivalent parts and clearing codes; access is generally straightforward compared with internal engine work. Typical repair cost is about $180 to $500 depending on how many sensors are replaced.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Infiniti VK45DE camshaft/crankshaft position sensorOEMInfiniti 23731-4M50D
replacement at the single diagnosed cam-phase or crank-position location Fitment/availability: Infiniti 23731-4M50D supersedes 4M50B/4M505/4M506 and is cataloged for the 2003-2008 FX45 VK45DE. The service catalog uses the same part at ca…
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
- TipIf the vehicle stalls hot and restarts after cooling down, check sensor data before replacing fuel system parts.
Sources for this issue (1)
The VK45DE V8 used in the FX45 can develop timing chain guide and tensioner wear, leading to chain rattle on startup or at idle. Owners report the issue more often on higher-mileage engines or vehicles with poor oil change history, where sludge and low oil pressure accelerate guide and tensioner wear.
Common Symptoms
- Rattling noise on cold start
- Metallic chain noise at idle
- Check engine light
- Rough running or timing-related misfire
- Noise from front of engine
How to Fix
Diagnosis usually starts with confirming front cover chain noise during cold start and checking oil condition, oil pressure, and cam/crank correlation data. Repair typically involves replacing timing chain guides, tensioners, and often the primary chain while the front timing cover is removed; parts and labor are substantial because of the engine teardown. Typical repair cost runs about $1,800 to $3,500 depending on how many timing components are replaced.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Infiniti VK45DE camshaft timing chainOEMInfiniti 13028-6N200
chain replacement after measurable wear, damage or timing-set service is confirmed Fitment/availability: Infiniti 13028-6N200 replaces 6N210 and fits the 2003-2008 FX45 VK45DE.
- Genuine Infiniti VK45DE right-side timing-chain tensionerOEMInfiniti 13070-AR000
right-bank chain-tensioner branch during confirmed timing-system repair Fitment/availability: Infiniti 13070-AR000 is the VK45DE right-side chain tensioner cataloged for 2003-2008 FX45. It is paired with, not substituted for, the left-si…
- Genuine Infiniti VK45DE left-side timing-chain tensionerOEMInfiniti 13070-AR015
left-bank chain-tensioner branch during confirmed timing-system repair Fitment/availability: Infiniti 13070-AR015 replaces AR010 and is cataloged for 2003-2008 FX45 VK45DE.
- Genuine Infiniti VK45DE right-side slack chain guideOEMInfiniti 13091-AR000
right-side slack-guide branch during confirmed complete timing-system service Fitment/availability: Infiniti 13091-AR000 is a right-side/slack-side VK45DE guide cataloged for 2003-2008 FX45. It is only one of four side-specific guides; A…
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
- TipUse high-quality synthetic oil and avoid extended oil change intervals, since dirty oil is commonly blamed for accelerating chain guide and tensioner wear.
- TipIf startup rattle lasts more than a second or becomes frequent, inspect it early before chain slack causes cam timing faults.
Sources for this issue (1)
P0340 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0340 mean on a Infiniti?
P0340 stands for "Camshaft Position Sensor Circuit Malfunction." This code means the engine computer lost or received an erratic signal from the camshaft position sensor. That sensor tells the computer the exact position and speed of the camshaft, which it uses together with the crankshaft sensor to time fuel injection and spark precisely. When the camshaft signal is missing, intermittent, or out of range, the computer sets P0340. Symptoms often include hard starting, stalling, rough running, or a no-start because the engine can't time itself correctly. On Infiniti it is documented across 7 models: M37, G35, FX35, M35, FX45, M56, QX50.
What are the most common causes of P0340?
The most common causes of P0340 are: Failed camshaft position sensor, Corroded or loose sensor connector, Damaged or shorted sensor wiring, Bad reluctor/tone ring on the camshaft, Loose timing chain/belt or jumped timing, Metal debris or oil contamination on the sensor tip, Poor sensor power or ground supply, Faulty PCM/ECM (rare). The specific cause varies by vehicle.
How much does it cost to fix P0340 on a Infiniti?
Published repair estimates on Infiniti range from $150 to $5,000 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0340 on a different make?
View P0340 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.