P0122 means the ECU is seeing an abnormally low voltage on throttle position sensor circuit A, typically under 0.2V when it expects 0.5V to 4.5V. Most cars drop into limp mode with capped throttle.
P0122 means the ECU is seeing an abnormally low voltage on throttle position sensor circuit A, typically under 0.2V when it expects 0.5V to 4.5V. Most cars drop into limp mode with capped throttle.
P0122 is a electrical-related diagnostic trouble code classified as moderate severity. When your vehicle's ECU detects this condition, it stores P0122 and illuminates the check engine light.
If your vehicle has triggered P0122, you may notice one or more of these symptoms:
Here are the most common causes of P0122, ranked by how likely they are to be the culprit:
No - address this immediately. The ECU usually forces the car into limp mode with reduced power and a locked idle. You can limp home, but hard acceleration and highway merging become risky.
Follow these steps to pinpoint the root cause of P0122:
Repair costs for P0122 vary depending on the root cause and your vehicle. Here are typical estimates:
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0122 behaves differently depending on your vehicle. Select your car below for model-specific causes, known issues, and adjusted cost estimates:
Volkswagen Golf
See Volkswagen-specific causes & costFord F-150
See Ford-specific causes & costToyota Camry
See Toyota-specific causes & costBMW 3-Series
See BMW-specific causes & costHonda Civic
See Honda-specific causes & costThese codes are often seen alongside P0122 or indicate related issues:
You can move the car short distances, but limp mode caps power and makes merging or overtaking dangerous. Fix it before any highway driving.
It'll clear the light, but if the sensor or wiring is faulty the code returns within minutes of driving. You're masking the problem, not fixing it.
Yes, on almost every drive-by-wire vehicle. Without the relearn the idle will hunt or stall. Most OBD2 apps with bidirectional control can run it in under a minute.
The connector probably wasn't fully seated, or carb cleaner seeped into the TPS. Reseat the plug and let it dry overnight before condemning parts.
Yes. If system voltage drops below about 10V during cranking or under load, the 5V reference can sag and log a low-input code. Load-test the battery before chasing sensors.
A failing throttle body shows up as a hunting idle, stalling, hesitation or limp mode. What the part does, the symptoms, the codes, and the repair cost.
The Reduced Engine Power message is the ECU cutting throttle to protect itself. Here is what triggers it, whether you can drive, and what the fix costs.
Clean a sooty throttle body in under an hour for around 15 euros, handle the idle-relearn question honestly, and verify the fix with OBD2 live data.
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An unfamiliar light just appeared on your dashboard and you have no idea what it means. Here is how to read every symbol by colour and which ones mean stop now.
Your car logged P0122. Skanyx reads it on any standard Bluetooth OBD2 adapter, tells you whether it is safe to keep driving, and breaks down the likely repair so you know the number before a shop quotes you.
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