OBD-II trouble code
P2125: Throttle/Pedal Position Sensor 'E' Circuit
A fault in the accelerator pedal's "E" position sensor circuit — the redundant second signal the computer uses to double-check what the pedal is doing.
Quick facts
- System
- Powertrain
- Category
- Throttle / Idle
- Severity
- High severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $100 – $450
- DIY difficulty
- Intermediate DIY
What does P2125 mean?
Drive-by-wire pedals carry at least two position sensors — D and E — whose signals track together in a fixed relationship (often one at roughly half the voltage of the other, or moving in opposite directions). That redundancy lets the computer instantly catch a lying sensor. P2125 is the general circuit code for sensor E: its signal is missing, out of range, or electrically implausible. Companions P2127 and P2128 flag it specifically stuck low or high.
With one of its two pedal inputs untrustworthy, the computer typically limits throttle authority — reduced power, capped RPM, sluggish response — rather than shutting you down entirely, since sensor D still provides a cross-checked signal on most strategies.
Causes concentrate in the same places as all pedal-sensor codes: the pedal assembly itself, its connector, the harness to the PCM, and the shared 5-volt reference/ground (a reference fault often sets multiple sensor codes at once — a valuable clue). The fix for a genuinely failed sensor is nearly always a complete pedal assembly.
Common causes
- Failed pedal position sensor E within the pedal assembly
- Corroded or loose pedal connector terminals
- Open or shorted wiring in the E circuit
- Missing/unstable 5-volt reference or ground (check for companion sensor codes)
- Water intrusion at the pedal connector (driver footwell leaks)
Symptoms
- Check engine light on
- Reduced power / limp mode
- Sluggish or capped throttle response
- Elevated or fixed idle in some strategies
- Possible companion codes P2127/P2128 or D-sensor codes
Diagnostic steps
- 1.Scan all modules — multiple 5-volt-reference sensor codes at once point at the shared reference, not the pedal.
- 2.Watch pedal D and E voltages on live data while sweeping the pedal: E should track its defined relationship to D smoothly.
- 3.Inspect the pedal connector for corrosion, water staining, and terminal tension.
- 4.Verify 5-volt reference and ground at the pedal connector.
- 5.Check harness continuity from pedal to PCM if the signal is dead with reference good.
- 6.Replace the accelerator pedal assembly if sensor E is confirmed faulty; clear codes and road-test.
Repair cost
$100 – $450
An accelerator pedal assembly typically costs $80-$300 with quick installation. Wiring and connector repairs are cheaper. Rule out the shared 5-volt reference first — replacing a pedal for a reference-circuit fault is a common wasted repair.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with accelerator pedal position sensor replacement preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
This is an intermediate DIY job. It usually involves diagnostic steps, specialty parts, and some careful work in tight spaces. If you have the tools and a service manual or trustworthy video for your specific vehicle, it is achievable in a weekend. Otherwise, a competent independent shop will be faster.