P0725 on Infiniti: How to Diagnose & Fix
Engine Speed Input Circuit Malfunction
2 Infiniti models · 2 documented issues · $150-$450 repair
P0725 on Infiniti by model: symptoms, diagnosis and fix
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.
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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 (2)
The 3.5L V6 used in the M35 (VQ35DE in 2006-2008, VQ35HR in 2009-2010) 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
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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 (4)
P0725 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 P0725 mean on a Infiniti?
P0725 stands for "Engine Speed Input Circuit Malfunction." This generic powertrain code means the transmission control module (or PCM) is not receiving a valid engine-speed (RPM) signal. On many vehicles, including Nissan, the crankshaft position sensor generates the signal, the ECM processes it, and the ECM passes it to the TCM over a wire or the CAN bus. The TCM uses engine speed for shift timing and torque converter lockup, and it sets the code when that signal is missing, drops out or reads illogically. It points to the engine-speed signal path (sensor, wiring, CAN network or modules), not to a fault inside the transmission. Input/turbine speed sensor faults are covered by P0715. On Infiniti it is documented across 2 models: FX35, M35.
What are the most common causes of P0725?
The most common causes of P0725 are: Faulty crankshaft position (engine speed) sensor or signal dropout, Damaged, corroded, or loose wiring or connectors in the engine-speed signal path, CAN communication circuit fault between ECM and TCM, Poor ground or power supply to the sensor or modules, Faulty TCM or ECM (rare). The specific cause varies by vehicle.
How much does it cost to fix P0725 on a Infiniti?
Published repair estimates on Infiniti range from $150 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.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.