The P2123: Throttle/Pedal Position Sensor/Switch ‘D’ Circuit High refers to an issue where the throttle or pedal position sensor ‘D’ is receiving a higher-than-expected voltage or signal. This can be caused by a faulty sensor or wiring issues.
P2123 – Quick Overview
Code | Information |
---|---|
Meaning | P2123: Throttle/Pedal Position Sensor/Switch ‘D’ Circuit High |
Is it serious? | Yes, it can affect throttle response and lead to drivability issues. |
Possible causes | – High voltage or signal from throttle/pedal position sensor ‘D’ – Faulty sensor – Wiring issues |
How to diagnose? | – Measure voltage or signal from the sensor – Test the sensor for faults – Inspect wiring and connections |
P2123 Meaning
The P2123 code indicates that the throttle/pedal position sensor ‘D’ is experiencing a higher-than-normal voltage or signal input. This issue can prevent the throttle from responding correctly, leading to poor vehicle performance. It is often caused by a defective sensor, wiring problems, or electrical faults.
Step-by-step diagnostic guide
Action | Description | Tools Needed |
---|---|---|
Check for Other Codes | Use an OBD-II scanner to check for other related codes that could provide more insight into the issue. | OBD-II Scanner |
Inspect Throttle/Pedal Sensor Wiring | Visually inspect the wiring and connectors for the throttle/pedal position sensor ‘D’ for any signs of damage, loose connections, or corrosion. | Flashlight, Multimeter |
Measure Voltage or Signal | Use a multimeter to measure the voltage or signal being sent by the throttle/pedal position sensor ‘D’. Compare the readings to manufacturer specifications. | Multimeter |
Test Sensor for Faults | Use a diagnostic tool to test the throttle/pedal position sensor ‘D’ for any internal faults or malfunctions. | Diagnostic Tool |
Inspect Wiring for Shorts | Check the wiring connected to the throttle/pedal position sensor ‘D’ for any shorts, open circuits, or other issues. | Multimeter, Wiring Diagram |
Clear the Code and Test Drive | After repairs or adjustments, clear the code with an OBD-II scanner and take the vehicle for a test drive to confirm the issue is resolved. | OBD-II Scanner |
Recheck for Codes | After the test drive, re-scan the vehicle to ensure the P2123 code has not returned. | OBD-II Scanner |

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Hi, I am Juraj “Yuri” Lukacko. I got frustrated by unhelpful and scammy mechanics, so I decided to learn everything about car diagnostics myself. I test dozens of new car diagnostic tools every month along with learning new strategies to fix and customize cars. About Juraj Lukacko (Yuri)