If the normal throttle body percentage is 5-10% at idle, what might the percentage indicate if one throttle position sensor fails?

In the case of a throttle position sensor (TPS) failure, the reading may not accurately reflect the actual position of the throttle plate. At idle, a properly functioning throttle usually indicates a percentage between 5% and 10%, as this range reflects the minimal opening required to maintain engine operation while at rest.

However, if one of the throttle position sensors fails, it could lead to an erroneous reading that suggests a wider throttle opening than what is physically occurring. This might occur due to a short circuit or other electrical issues within the sensor, which can create a signal that indicates a higher reading, such as 35%.

As a result, if the throttle position sensor fails and reads a significantly higher percentage (like 35%), this point indicates a malfunction in the sensor, suggesting that the engine control unit (ECU) may incorrectly interpret the input as the throttle being more open than it actually is, potentially leading to issues such as increased engine RPM or a rough idle. This scenario emphasizes the importance of accurate readings from the throttle position sensors for proper engine operation.