Code P0123 on the 2024 Jeep Wrangler indicates the Throttle Position Sensor (TPS) signal voltage is higher than the expected range. This signals a potential issue with the throttle position sensing that affects how the ECM interprets driver throttle input.
Electronic Throttle Control
The Wrangler uses drive-by-wire throttle control where the accelerator pedal sensor tells the ECM driver intent, and the ECM controls the electronic throttle body. The TPS on the throttle body provides feedback confirming actual throttle position matches commands.
High Voltage Indication
The TPS outputs voltage proportional to throttle opening - low voltage when closed, higher voltage when open. P0123 sets when voltage is higher than expected for the current conditions, suggesting the throttle is more open than it should be, or the sensor is reporting incorrectly high.
Symptoms
With P0123, the ECM may enter reduced power mode to prevent unintended acceleration. The engine may idle high, hesitate, or surge. The accelerator may feel unresponsive as the ECM limits throttle control due to conflicting sensor data.
Common Causes
Faulty TPS (internal sensor failure), wiring short to voltage source, connector corrosion, or throttle body issues can cause high TPS readings. On the Wrangler, off-road conditions can introduce moisture and debris that affect electrical connections.