OBD-II trouble code
P2126: Throttle/Pedal Position Sensor 'E' Circuit Range/Performance
Pedal sensor E's signal is present but implausible — it disagrees with sensor D or doesn't track pedal movement the way it should.
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
Browse every code in P2100–P2199, or start from the full code library.
What does P2126 mean?
P2126 is the rationality-check code for pedal position sensor E. The signal isn't dead, pinned low (P2127), or pinned high (P2128) — it's producing values the computer doesn't believe: disagreeing with sensor D beyond tolerance, reading a pedal angle that's physically impossible, or lagging real pedal movement.
Range/performance faults on pedal sensors usually mean a sensor that has drifted or developed a nonlinear spot, or resistance in the sensor's reference or ground skewing (rather than killing) the signal — corroded terminals are expert at this, and because the pedal sensor is a voltage divider, resistance in its supply or its ground scales the output proportionally instead of just offsetting it. Contamination or water at the connector pulls the voltage subtly off the same way. Genuine correlation disagreements between D and E are also covered by P2138, which often accompanies this code.
As with all pedal-signal doubts, the computer limits throttle authority while the fault is present. The live-data pedal sweep is decisive: watch D and E together across the full pedal travel, looking for the point where E departs from its expected relationship.
Common causes
- Drifted or nonlinear pedal sensor E (worn/failing element)
- High-resistance connection — corroded terminals skewing the signal
- Water or contamination at the pedal connector
- Slightly unstable 5-volt reference loading the signal
- Failing pedal assembly electronics
Symptoms
- Check engine light on
- Reduced power or dulled throttle response
- Hesitation at specific pedal positions
- Possible companion P2138 correlation code
- Normal behavior in some pedal ranges, faults in others
Diagnostic steps
- 1.Sweep the pedal slowly, key on, while graphing sensors D and E — look for a range where E's value departs from the expected relationship.
- 2.Inspect the pedal connector for corrosion or moisture, then test the reference and ground rather than the signal line. A voltage drop test on the signal wire is the instinctive move here and it does not work: that wire feeds a high-impedance module input and carries almost no current, so a resistive joint on it develops no measurable drop and passes the exact fault you are hunting. What does move is the divider's supply — back-probe the seated connector with the ignition on, compare the 5-volt reference at the pedal against what the module is putting out, and compare the sensor's ground against battery negative. Resistance in either scales E's whole output and shows up as the skew the code is describing.
- 3.Verify the 5-volt reference is stable under load.
- 4.Compare readings hot and cold if the fault is intermittent by temperature.
- 5.Replace the accelerator pedal assembly if E's output is proven nonlinear or drifted.
- 6.Clear codes, re-sweep, and road-test through full throttle range.
Repair cost
$100 – $450
Same economics as the rest of the pedal-sensor family: pedal assemblies run $80-$300 installed in most cases, and connector repairs are cheap. The diagnosis time to prove which side (pedal vs. wiring) is at fault is the main variable.
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.