Posts Tagged: check engine light repair

How to Diagnose a Throttle Position Sensor Code Like a Pro

Why Your Car Has a Throttle Position Sensor Code and How to Fix It Quick Summary Mechanical and electronic throttle systems use two internal throttle position sensors that work inversely to validate each other. A proper diagnosis requires an understanding of how both sensors share a 5-volt reference and ground, and how the ECM tracks the inverse signals to detect a fault. Once you understand reference voltage and ground, it’s easy to diagnose these common throttle position sensor codes: P0120 – Throttle/Pedal Position Sensor “A” Circuit P0121 – Throttle/Pedal Position … Read More