P0725: How to Diagnose & Fix — Engine Speed Input Circuit Malfunction
4 vehicles · 3 makes · $150-$1,200 repair
How to diagnose and fix P0725: most-reported vehicles
Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.
Nissan Altima · 2002–2012
Altimas in this period frequently suffer from failing crankshaft position sensors and camshaft position sensors, especially on the 2.5L and 3.5L engines. Owners report intermittent stalling at stops or while driving, extended cranking, sudden no-start conditions, and check-engine lights. Nissan issued service information and many owner reports describe repeat failures with cheap aftermarket sensors.
Common Symptoms
- engine stalls while driving
- intermittent no-start
- long crank time
- tachometer drops to zero
- check engine light
- hard restart when hot
How to Fix
Diagnosis includes scanning for correlation and sensor circuit codes, checking live RPM signal during cranking, and inspecting harness connectors for oil contamination or heat damage. The most reliable fix is replacing the failed sensor(s) with OEM-quality parts and clearing codes; in some cases both cam and crank sensors are replaced together due to similar age and failure patterns.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Nissan 23731-6N21A crankshaft position sensor
2002-2006 Nissan Altima 2.5L QR25DE; confirm VIN, DTC and sensor location because catalog terminology can overlap cam/crank/magnet sensor names.
- OEM Nissan 2002-2006 Altima 3.5L camshaft position sensor
2002-2006 Nissan Altima 3.5L VQ35DE; select the DTC-identified bank/side and verify current Nissan part number.
- Genuine Nissan 23731-JA00C crankshaft/magnet sensor
Confirm VIN, DTC and sensor location.
- Genuine Nissan 23731-JA11B camshaft position sensor
Verify VIN, DTC and location; do not infer quantity.
- Genuine Nissan 23731-JA10C crankshaft position sensor
2007-2012 Nissan Altima 3.5L VQ35DE for this card; confirm VIN, exact DTC and crank-sensor location.
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 OEM or OEM-supplier sensors; many owners report repeat failures within months when using the cheapest aftermarket cam/crank sensors.
- TipIf one sensor fails on a high-mileage car, many owners proactively replace the matching cam/crank sensors together to avoid another breakdown soon after.
Fiat Uno · 2011–2019
The single-clutch automated manual offered on the Novo Uno (Dualogic on the 1.4 Fire Evo, GSR on the 1.3 Firefly 'Uno Drive') is the model's most expensive weak point. Chronic failure modes documented by Brazilian transmission specialists include worn or mis-calibrated clutch actuators causing slipping and jerky engagement, hydraulic pressure loss from leaks (pump shuts down, codes P0942/P2712), failed gear/clutch position sensors (P0805/P0806, P0715/P0725) and TCU faults that force the transmission into emergency mode or drop it into neutral while driving. It became serious enough that in 2019 Fiat recalled 11,669 vehicles across 8 models — including 916 Uno 1.3 GSR units, model years 2017-2018 (chassis 796635 to 835113) — because the transmission could shift to neutral involuntarily, causing sudden loss of drive.
Common Symptoms
- Transmission drops into neutral by itself while driving
- Jerky or delayed gear engagement
- Clutch slipping during shifts
- Reverse gear refuses to engage
- Gearbox warning light with transmission stuck in emergency mode
How to Fix
For 2017-2018 GSR cars: confirm the official recall (replacement of the gear selector sensor, ~1 hour, free) was performed. For chronic faults: scan the TCU for stored codes first; many problems are resolved by clutch actuator recalibration or replacement and hydraulic fluid/leak service rather than full transmission replacement. Worn clutches must be replaced with actuator recalibration. Use a shop experienced with Fiat Dualogic/GSR — incorrect calibration is a common cause of repeat failures.
Sources for this issue (1)
Infiniti FX35 · 2003–2012
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)
Infiniti M35 · 2006–2010
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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?
P0725 stands for "Engine Speed Input Circuit Malfunction." This generic powertrain code means the transmission control module or PCM is not receiving a reliable, rational engine-speed (or input/turbine) signal from its speed sensor. The computer compares this rotational-speed input against other sensors to manage shift timing and torque converter lockup, and it sets the code when that signal goes missing, drops out, or reads illogically. It usually points to a sensor or wiring problem in the speed-input circuit rather than an engine failure itself.
What are the most common causes of P0725?
The most common causes of P0725 are: Faulty engine/input speed sensor, Damaged, corroded, or loose sensor wiring or connector, Low or dirty transmission fluid, Open or shorted circuit between sensor and PCM/TCM, Poor ground or power supply to the sensor, Internal transmission damage affecting the sensor, Faulty PCM/TCM (rare). The specific cause varies by vehicle.
How much does it cost to fix P0725?
Repair costs for P0725 range from $150 to $1,200, depending on the vehicle and root cause.
Which vehicles are affected by P0725?
Au7o has documented P0725 across 4 vehicle models from 3 manufacturers: Fiat, Infiniti, Nissan.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.