P0123 Mercedes-Benz Code - Throttle/Pedal Position Sensor/Switch 'A' Circuit High Input
Quick Answer
This fault code is stored in the Engine Control Module (ECM) when a malfunction is detected in the throttle control system. Common causes include Faulty Accelerator Pedal Position Sensor, Accelerator Pedal Position Sensor harness is open or shorted, Accelerator Pedal Position Sensor circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P0123 Mercedes-Benz indicates Throttle/Pedal Position Sensor/Switch 'A' Circuit High Input.
- Common causes
- Common causes include Faulty Accelerator Pedal Position Sensor, Accelerator Pedal Position Sensor harness is open or shorted, Accelerator Pedal Position Sensor circuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P0123 Mercedes-Benz Description
What are the Possible Causes of the DTC P0123 Mercedes-Benz?
- Faulty Accelerator Pedal Position Sensor
- Accelerator Pedal Position Sensor harness is open or shorted
- Accelerator Pedal Position Sensor circuit poor electrical connection
- Faulty Throttle Position Sensor (TPS)
- Faulty Engine Control Module (ECM)
How to Fix the DTC P0123 Mercedes-Benz?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0123 Mercedes-Benz code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P0123 Mercedes-Benz Code
1. What are the common symptoms of OBDII code P0123 in a Mercedes-Benz?
- Common symptoms include issues with acceleration, lack of power, potential stalling, and the vehicle going into limp mode.
2. What are the possible causes of OBDII code P0123 in a Mercedes-Benz?
- The code P0123 typically indicates a fault in the throttle/pedal position sensor/switch 'A' circuit, which could be caused by a faulty sensor, wiring issues, or a problem with the throttle body.
3. How can I diagnose the throttle/pedal position sensor/switch 'A' circuit high input issue in my Mercedes-Benz?
- Diagnosis usually involves using an OBDII scanner to read the code, checking the sensor's wiring for any damage or loose connections, and testing the sensor's output with a multimeter.
4. Can I drive my Mercedes-Benz with OBDII code P0123?
- It is not recommended to drive with this code present, as it can lead to performance issues and potentially cause further damage to the vehicle.
5. How can I repair OBDII code P0123 in my Mercedes-Benz?
- Repairing the issue involves replacing the faulty throttle/pedal position sensor, repairing any damaged wiring, or addressing any underlying throttle body problems.
6. Are there any DIY tips for fixing OBDII code P0123 in a Mercedes-Benz?
- DIY tips include checking the sensor's connector for corrosion, ensuring proper sensor alignment, and following manufacturer-specific repair procedures.
7. Will resetting the OBDII code P0123 in my Mercedes-Benz make it go away permanently?
- Resetting the code may temporarily clear it, but if the underlying issue is not addressed, the code is likely to return.
8. Is it necessary to visit a mechanic for OBDII code P0123 in a Mercedes-Benz?
- While some DIY repairs are possible, seeking professional help from a qualified mechanic is recommended for accurate diagnosis and proper repair of this code.
9. Can a dirty throttle body cause OBDII code P0123 in a Mercedes-Benz?
- Yes, a dirty or malfunctioning throttle body can disrupt the sensor's readings and contribute to the triggering of code P0123.
10. How much does it typically cost to repair OBDII code P0123 in a Mercedes-Benz?
- The cost of repair can vary depending on the exact cause of the issue, but it may involve sensor replacement, wiring repairs, or throttle body maintenance, with costs ranging from a few hundred to over a thousand dollars.
Discuss the causes and fixes for P0123 Mercedes-Benz OBDII Code
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Repaired 2002 C200 Kompressor.
Symptoms/fault generation - if accelerator was pushed swiftly all the way to the floor P0123 coded and limp home throttle response active until ignition was cycled off for 10 seconds.
Fault is in APP sensor were sensor 1 over shoots the maximum allowable voltage of 4.9Volts. If it goes even slightly over this P0123 will code.
Repair by replacing with new APP sensor or a temporary repair is to fit a stopper so that accelerator does not quite go as far but still enough to operate Kick down.
Sensor 1 output of 4.7 to 4.9 at full throttle is acceptable
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