P0123 means the ECU sees TPS 'A' signal voltage above the upper threshold (typically 4.8V of the 5V reference). The computer ignores the throttle input and falls back to limp mode.
P0123 means the ECU sees TPS 'A' signal voltage above the upper threshold (typically 4.8V of the 5V reference). The computer ignores the throttle input and falls back to limp mode.
P0123 is a electrical-related diagnostic trouble code classified as moderate severity. When your vehicle's ECU detects this condition, it stores P0123 and illuminates the check engine light.
If your vehicle has triggered P0123, you may notice one or more of these symptoms:
Here are the most common causes of P0123, ranked by how likely they are to be the culprit:
No - address this immediately. You can drive short distances, but most vehicles trigger limp mode with reduced throttle response. Sudden power loss is possible, so get it diagnosed before longer trips.
Follow these steps to pinpoint the root cause of P0123:
Repair costs for P0123 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.
P0123 behaves differently depending on your vehicle. Select your car below for model-specific causes, known issues, and adjusted cost estimates:
VW Golf
See Volkswagen-specific causes & costFord F-150
See Ford-specific causes & costBMW 3-Series
See BMW-specific causes & costToyota Camry
See Toyota-specific causes & costHonda Civic
See Honda-specific causes & costThese codes are often seen alongside P0123 or indicate related issues:
No. It's a hard electrical fault. The MIL might go out after several drive cycles without the fault recurring, but the underlying wiring or sensor issue almost always comes back within minutes.
Yes. It's a stored powertrain code with the MIL on, which is an automatic fail at any OBD2 inspection.
On older cable-throttle cars (mostly pre-2005) the TPS is a bolt-on €40-80 part. On drive-by-wire systems the sensor is integrated into the throttle body and you replace the whole assembly.
The PCM can't trust the throttle signal, so it ignores the pedal and holds the throttle at a fixed low opening (usually 1200-1500 RPM) to prevent unintended acceleration.
Yes, on nearly all drive-by-wire cars. Most brands need a specific idle/throttle relearn procedure (Toyota, Honda, VW, BMW all have their own). Skipping this leaves rough idle even after a good part is fitted.
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.
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.
A flashing check engine light is not the same as a steady one. It almost always means an active misfire that can wreck your catalytic converter in minutes.
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 P0123. 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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