What does P2138 mean?
Most electronic accelerator pedals have two position sensors that must always agree. P2138 means the two pedal position signals (D and E) do not match.
Codes are a starting point. They tell you which test failed, not which part to replace. Check for other stored codes and fix those in a sensible order.
Symptoms
- Reduced power or limp mode
- Slow response to the pedal
- Check engine light
Common causes
- Worn accelerator pedal sensor
- Wiring or connector fault
- Low system voltage
How to diagnose P2138
- Compare both pedal signals in live data while slowly pressing the pedal.
- Check connector and wiring at the pedal.
How to fix it
- Replace the accelerator pedal assembly
- Repair wiring
Estimated repair cost
Likely repairs for P2138 run from about $100 to $400, depending on the cause.
| Repair | Typical range (parts + labor) |
|---|---|
| Diagnostic fee (scan + testing) | $100 - $200 |
| Accelerator pedal sensor assembly | $150 - $400 |
| Wiring/connector repair | $100 - $400 |
These are rough US estimates for an independent shop in 2026, based on typical parts prices and standard labor times. Dealers, big trucks, luxury brands and high-cost areas often run higher. They are not quotes. Use the repair cost estimator to adjust for your vehicle.
How serious is P2138?
High severity
Limp mode can limit acceleration, which is risky in traffic.
Make-specific notes
GM
P2138 on GM trucks is often a worn pedal assembly, but check the throttle body connector and grounds too.
Always check open recalls and technical service bulletins for your VIN.
P2138 FAQ
What does P2138 mean?
P2138 stands for "Throttle/Pedal Position Sensor/Switch "D"/"E" Voltage Correlation". Most electronic accelerator pedals have two position sensors that must always agree.
Can I drive with a P2138 code?
Limp mode can limit acceleration, which is risky in traffic.
How much does it cost to fix P2138?
It depends on the cause. The likely repairs for P2138 range from about $100 to $400 at an independent shop in the US, plus a diagnostic fee of roughly $100-$200. These are rough estimates; dealer prices and some vehicles run higher.
What is the most common cause of P2138?
The most common causes are: worn accelerator pedal sensor; wiring or connector fault; low system voltage.