P0120 on Toyota: How to Diagnose & Fix
Throttle/Pedal Position Sensor Circuit Malfunction
1 Toyota model · 1 documented issue · 1 critical
P0120 on Toyota by model: symptoms, diagnosis and fix
Owners of 2006-2010 Corollas equipped with the electronic throttle control system (ETCS-i) reported episodes of low-speed surging — the car lunging or accelerating slightly on its own at low speed (e.g., in parking lots or creeping traffic) such that braking sometimes felt insufficient to stop in time. NHTSA received a petition and opened scrutiny covering roughly 1.69 million 2006-2010 Corollas with electronic throttle control, separate from (and in addition to) the well-known floor-mat-entrapment and sticky-accelerator-pedal recalls of the same era. While Toyota and NHTSA's technical reviews did not confirm an electronic root cause, the surging complaints are numerous, well-documented, and a frequent owner search.
Common Symptoms
- Vehicle lunges or surges forward at low speed
- Brief unexpected acceleration in parking lots / stop-and-go traffic
- Higher-than-expected idle or RPM creep
- Brake pedal feels like it must be pressed harder to stop
- Hesitation followed by surge on tip-in
How to Fix
First rule out the known mechanical recall causes: verify the floor-mat-entrapment and accelerator-pedal recalls are completed for your VIN at toyota.com/recall (floor-mat shimming/pedal replacement). Ensure only correct, properly secured Toyota all-weather mats are used. Have the throttle body cleaned and the accelerator pedal position sensor and ETCS checked; clear any stored throttle/idle codes. If surging persists, document it (dashcam/video), report it to NHTSA, and have a dealer inspect for throttle/idle-control faults.
Sources for this issue (3)
P0120 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0120 mean on a Toyota?
P0120 stands for "Throttle/Pedal Position Sensor Circuit Malfunction." This code indicates a malfunction in the throttle position or accelerator pedal position sensor circuit. These sensors tell the computer how far the throttle plate is open or how far you've pressed the pedal, which the computer uses to control engine power and, on drive-by-wire systems, the throttle itself. When the signal is out of range, erratic, or doesn't make sense relative to other inputs, P0120 sets. Symptoms can include hesitation, surging, stalling, or the vehicle entering a reduced-power 'limp' mode for safety. On Toyota it is documented across 1 model: Corolla.
What are the most common causes of P0120?
The most common causes of P0120 are: Failed throttle position sensor, Corroded or loose TPS/pedal sensor connector, Damaged or shorted sensor wiring, Carbon buildup or a sticking throttle body, Worn throttle body or throttle plate, Poor sensor reference voltage or ground, Faulty accelerator pedal position sensor, Faulty PCM/ECM (rare). The specific cause varies by vehicle.
How much does it cost to fix P0120 on a Toyota?
Repair costs vary widely with the root cause and Toyota model; each issue on this page carries its own estimate where one is published.
Looking for P0120 on a different make?
View P0120 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.