P0390 on Infiniti: How to Diagnose & Fix
Camshaft Position Sensor "B" Circuit (Bank 2)
1 Infiniti model · 1 documented issue · $180-$450 repair
P0390 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)
P0390 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 P0390 mean on a Infiniti?
P0390 stands for "Camshaft Position Sensor "B" Circuit (Bank 2)." This code means the PCM detected a circuit problem with the 'B' camshaft position sensor on Bank 2 (the cylinder bank opposite Bank 1, typically on V-type engines). This sensor monitors camshaft position so the computer can time fuel delivery, ignition, and variable valve timing accurately. A fault can lead to rough running, reduced power, hard starting, or variable valve timing problems. It is generally not an immediate breakdown but should be diagnosed to prevent driveability issues. On Infiniti it is documented across 1 model: M37.
What are the most common causes of P0390?
The most common causes of P0390 are: Faulty camshaft position sensor (Bank 2, sensor B), Damaged wiring or connector at the sensor, Open or short in the sensor circuit, Corroded or loose connector terminals, Reluctor/tone ring damage on the camshaft, Failing PCM (less common). The specific cause varies by vehicle.
How much does it cost to fix P0390 on a Infiniti?
Published repair estimates on Infiniti range from $180 to $450 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 P0390 on a different make?
View P0390 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.