Throttle position sensor out of range
Your throttle position sensor is sending a signal outside the normal operating range, like a volume knob stuck in an extreme position. The engine computer can't accurately read how far open your throttle is, causing drivability issues.
The ECU monitors the throttle position sensor voltage output (typically 0.5V closed to 4.5V wide open) to determine throttle angle and adjust fuel injection and spark timing accordingly. If the signal voltage falls outside the acceptable range or doesn't respond proportionally to throttle input, the ECU triggers this fault code.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| TPS Voltage | 0.5V to 4.5V with smooth transition | Below 0.5V or above 4.5V; erratic/non-linear response |
| TPS Sweep Rate | Voltage change correlates to throttle movement | Voltage jumps or lags relative to throttle position |
Code P1125 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P1125 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.