P0123 Throttle Position Sensor/Switch A Circuit High Input

Description and meaning of DTC p0123

This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles. Although generic, the specific repair steps may vary depending on make/model. The TPS (Throttle Position Sensor) is a potentiometer that is mounted to the throttle body. It detects the throttle blade angle. As the throttle blade moves, the TPS sends a signal to the PCM (Powertrain Control Module), which is the main computer that runs the vehicle. Usually a three wire sensor: A 5 volt reference from the PCM to the TPS, a ground from the PCM to the TPS, and a signal return from the TPS to the PCM. The TPS sends the throttle position information back to the PCM on this signal wire. When the throttle is closed the signal is near . 45 volts. At WOT (Wide Open Throttle) the TPS signal voltage will approach a full 5 volts. When the PCM sees a voltage that is higher than the normal upper limit, P0123 will set.

p0123 diagnostic trouble code symptoms

Symptoms may include:Rough idleHigh idleSurgingother symptoms may also be present

DTC p0123 - possible causes

A code P0123 may mean that one or more of the following has happened:TPS not mounted securelyTPS circuit short to ground or another wireFaulty TPSDamaged computer (PCM)

How to fix OBD-II diagnostic trouble code p0123

A good starting point is always to check for technical service bulletins (TSB) for your particular vehicle. Your issue may be a known issue with a known fix put out by the manufacturer and can save you time and money during diagnosis. If there are no symptoms, the simplest thing to do is to reset the code andsee if it comes back. If there are symptoms such as the engine is stumbling or hesitating, carefullyinspect all wiring and connectors that lead to the TPS. More than likely theproblem is with the TPS wiring. Check the voltage at the TPS (refer to a servicemanual for your vehicle for this specific information). If the voltage spikesor is too high (over 4. 65 volts with key on, engine off), then that is indicativeof a problem. Carefully trace each wire from the TPS wiring harness to checkforbreaks,rubbing against other components, etc. Other TPS sensor and circuit related DTCs: P0120, P0121, P0122, P0123, P0124

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