P2135 on Toyota: How to Diagnose & Fix
Throttle/Pedal Position Sensor Voltage Correlation
1 Toyota model · 1 documented issue · 1 critical
P2135 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)
P2135 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 P2135 mean on a Toyota?
P2135 stands for "Throttle/Pedal Position Sensor Voltage Correlation." P2135 means the powertrain computer detected that the two throttle position (TP) or accelerator pedal position sensors disagree with each other. Drive-by-wire systems use redundant sensors so the PCM can cross-check the throttle or pedal reading for safety; if the two signals don't correlate within an expected range, this code sets. As a fail-safe, the vehicle often enters a reduced-power 'limp' mode, causing sluggish acceleration, a stuck or hesitant throttle, and a warning light. Because it affects throttle control, it should be addressed promptly. On Toyota it is documented across 1 model: Corolla.
What are the most common causes of P2135?
The most common causes of P2135 are: Faulty throttle position sensor / throttle body assembly, Faulty accelerator pedal position sensor, Damaged wiring or connectors at the throttle body or pedal, Corroded or loose connector terminals, Poor ground or reference voltage problem, Carbon buildup binding the electronic throttle plate, Failed PCM (rare). The specific cause varies by vehicle.
How much does it cost to fix P2135 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 P2135 on a different make?
View P2135 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.