P2138 on Nissan: Causes, Fix Cost & Diagnosis | AXLY.pro

Nissan Check Engine Code

P2138 on Nissan

Throttle / Pedal Position Sensor D / E Voltage Correlation

Severity: high DIY difficulty: 2/5 Nissan cost: $150–$450

Also covers: Infiniti

P2138 on Nissan: what makes it different

P2138 is a frequent flyer on Nissan's electronic throttle control (drive-by-wire) vehicles, where the accelerator pedal position sensor has two internal sensors that must track each other closely — on many Nissan models these sensors are known to drift out of correlation over time.

Most-affected engines

  • QR25DE 2.5L (Altima, Sentra)
  • MR20DE 2.0L (Sentra, Rogue)
  • VQ35DE/VQ35DE 3.5L V6 (Altima, Maxima)

Common model years: 2007–2015

Most likely cause on Nissan

Accelerator pedal position sensor with two internal signal circuits drifting out of correlation

Known Nissan engine-family issues

Nissan's electronic accelerator pedal assemblies on this era of Altima, Sentra, and Rogue use a combined pedal-and-sensor unit rather than a separate cable-actuated sensor, so when the internal sensors drift, the whole pedal assembly is usually replaced as one unit rather than repairing an individual sensor.

Nissan-specific causes (most common first)

  1. Worn or drifting accelerator pedal position sensor (dual-sensor unit losing correlation between its two circuits)
  2. Throttle body position sensor correlation fault on the electronic throttle body itself
  3. Corroded or damaged wiring/connector at the pedal assembly harness
  4. Water intrusion at the pedal sensor connector (common in vehicles parked outdoors)
  5. ECU-side fault interpreting normal sensor variance as a correlation error after a battery disconnect or reset

Nissan-specific diagnostic tip

With a scan tool, watch both APP sensor voltage traces side-by-side while slowly pressing the pedal — Nissan's correlation logic flags when the two signals diverge beyond a set tolerance, so a visible gap or one sensor lagging the other points straight to the pedal assembly rather than the throttle body.

Symptoms drivers report

  • Check engine light
  • Reduced engine power / limp mode
  • No throttle response
  • Stalling

Typical repair cost on Nissan

Most Nissan owners fix P2138 for between $150 and $450, depending on which underlying cause turns out to be at fault. Start with the most-likely cause for your vehicle — Accelerator pedal position sensor with two internal signal circuits drifting out of correlation — before throwing parts at it.

Nissan P2138 FAQ

Will P2138 cause my Nissan to go into limp mode?

Often yes. Nissan's ECU treats accelerator pedal sensor correlation faults as safety-related, so it commonly limits engine power or triggers reduced-power mode until the fault is cleared.

Is it the throttle body or the gas pedal causing P2138?

On most Nissan models it's the accelerator pedal position sensor rather than the throttle body — but it's worth scanning both sensor sets since a throttle body correlation fault can trigger a similar code.

Can I clean the connector instead of replacing the pedal assembly?

If the issue is corrosion or a loose connector, cleaning and reseating it can resolve the code. But if the internal sensor voltages themselves are drifting, the pedal assembly typically needs replacement since the sensors aren't sold separately.

Related codes

P2122P2123P2127P2128

Drive a different make? See the general P2138 guide for cross-vehicle causes and symptoms.

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