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DTC codes / Chrysler codes / P1271

P1271 · ChryslerAPP Sensor 1-2 Performance

P1271 on Chrysler vehicles means the powertrain control module (PCM) has detected a performance problem with the Accelerator Pedal Position (APP) sensor circuit, specifically comparing the signals from APP Sensor 1 and APP Sensor 2. The two sensors are designed to produce voltages that correlate in a predictable way, and when the PCM sees a disagreement or an out-of-range signal from either sensor, it sets this code and typically limits engine power.

SystemPowertrain
Code typeChrysler specific
SeverityMedium
Fix difficultyIntermediate
AreaFuel and air metering (injector circuits)

Symptoms you may notice

  • The electronic throttle control (ETC) warning light or check engine light illuminates on the dashboard.
  • The engine may enter limp mode, limiting speed to a low threshold or causing the accelerator pedal to feel unresponsive.
  • The vehicle may hesitate, stumble, or surge unexpectedly when you press the accelerator pedal.
  • The pedal may feel dead or require excessive force to accelerate, or it may not return to idle properly.
  • Often no symptoms besides the warning light, especially if the fault is intermittent and the PCM has not yet defaulted to limp mode.

Common causes, most likely first

  1. A faulty accelerator pedal position sensor assembly, where one of the two internal sensors has worn out or developed a dead spot.
  2. Corroded, loose, or damaged wiring and connectors at the APP sensor or the PCM, causing intermittent signal loss.
  3. A poor ground connection for the APP sensor circuit, leading to voltage offsets that the PCM interprets as a performance fault.
  4. A malfunctioning PCM, although this is rare and should only be suspected after all other causes are ruled out.
  5. Water intrusion or contamination in the APP sensor connector, often from a leaking windshield or cowl seal.
  6. Aftermarket floor mats or debris obstructing the pedal travel, causing the sensors to report implausible positions.

How to diagnose and fix it

  1. Use a scan tool to read the APP sensor 1 and sensor 2 voltages in live data while slowly pressing and releasing the pedal; look for smooth, proportional changes and no dropouts.
  2. Visually inspect the APP sensor connector and wiring for corrosion, chafing, or loose pins, and check that the pedal moves freely without obstruction.
  3. Check the APP sensor ground circuit for excessive resistance using a multimeter, and clean or repair any poor ground connections.
  4. Perform a wiggle test on the harness while watching live data to catch intermittent wiring faults that only appear when the vehicle is moving.
  5. If live data shows one sensor dropping out or not matching the expected correlation, replace the accelerator pedal assembly with a quality OEM part.
  6. After replacement, clear the codes and perform a throttle relearn or ETC calibration procedure as required for the specific Chrysler model.
  7. If all sensor and wiring checks pass but the code persists, diagnose the PCM and its connectors before condemning the module.

Why APP sensor codes get misdiagnosed

  • Many technicians replace the accelerator pedal assembly only to find the real problem is a corroded connector or a chafed wire in the harness, so always perform a wiggle test and voltage drop check before parts swapping.
  • A weak battery or charging system can cause voltage fluctuations that mimic APP sensor faults, so verify battery health and ground integrity before condemning the sensor.
  • The APP sensor is often contaminated by spilled drinks or debris around the pedal, which can cause intermittent signal dropouts that do not appear during a static test.
  • On some Chrysler models, the APP sensor signals are compared with the throttle position sensor signals, and a fault in the throttle body can set a code that appears to point to the pedal.
  • Aftermarket floor mats that bunch up under the pedal can cause the PCM to see implausible APP sensor correlation, setting P1271 even though the sensor itself is fine.

Can I keep driving with P1271?

You can usually drive the vehicle to a repair shop if the engine is not in limp mode, but avoid aggressive acceleration and be prepared for the throttle to become unresponsive if the fault worsens. If the vehicle enters limp mode or the pedal stops responding, pull over safely and have it towed.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for Chrysler vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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