How much does it cost to fix P2138?

DIY repair typically costs $50–$250 for parts. Professional repair runs $200–$700 including parts and labor.

P2138

Powertrain

High

Throttle/Pedal Position Sensor/Switch "D"/"E" Voltage Correlation

Get Your FREE AI Diagnostic Report

Enter your vehicle for a personalized diagnosis for code P2138

Code P2138 is a critical safety-related fault that indicates the two position sensors (D and E) in your accelerator pedal are not producing the correlated voltage readings the engine computer expects. These dual sensors are designed as a safety system — by comparing two independent readings of pedal position, the PCM can detect if either sensor is malfunctioning. When the signals diverge beyond the allowed tolerance, this code is set.

This is one of the more dangerous throttle-related codes because it can cause sudden and unpredictable throttle behavior. You may experience a complete inability to accelerate, unintended acceleration, the engine being stuck at a fixed RPM, or the vehicle stalling in traffic. The computer may lock the throttle in a fixed position or cut power entirely as a safety measure.

Do not continue driving with this code active. The most common repair is replacing the accelerator pedal assembly, which includes both position sensors as an integrated unit. Before replacing parts, inspect the connector at the pedal for corrosion — a corroded pin can cause one sensor signal to read differently from the other. Some manufacturers have issued technical service bulletins for this code that involve a PCM reflash rather than hardware replacement, so it's worth checking with a dealer.

Severity

High — Immediate AttentionWithin 24 Hours

Symptoms

•Complete loss of throttle control or acceleration
•Engine stuck at current RPM or won't change speed
•Vehicle stalls when coming to a stop
•Sudden loss of power at highway speeds
•Check Engine Light on with reduced power warning

Likely Causes

Faulty accelerator pedal position sensor assembly40%

The D and E sensors inside the gas pedal assembly must produce correlated voltage signals. When one sensor drifts or fails, their outputs no longer match the expected relationship, and the PCM sets this correlation fault.

Corroded or damaged pedal connector25%

The electrical connector at the accelerator pedal can accumulate moisture, corrosion, or debris that disrupts the electrical contact for one or both sensor circuits, causing their voltages to disagree.

Wiring harness damage20%

Damaged insulation, pinched wires, or rodent damage in the harness running from the pedal to the PCM can alter the signal on one circuit without affecting the other, triggering the correlation fault.

PCM software or calibration issue15%

Some vehicles have known issues where a PCM software calibration update is needed to correctly interpret the D/E sensor signals, especially after unrelated repairs or battery disconnections.