Throttle/Petal Position Sensor/Switch ‘A’ Circuit High Input
Table of contents
P0123 MERCEDES-BENZ Possible Causes
- 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 do I fix code P0123 MERCEDES-BENZ?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Tech Notes
- Mercedes Benz Code = 0161 (Throttle valve actuator): Actual value potentiometer 1: Short circuit to positive or open circuit (P0123)
Cost of diagnosing the P0123 MERCEDES-BENZ code
The cost of diagnosing the P0123 MERCEDES-BENZ code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P0123 MERCEDES-BENZ Description
This fault code is stored in the Engine Control Module (ECM) when a malfunction is detected in the throttle control system. The driver demand is sensed via the accelerator pedal position sensor. The engine control module adjusts the throttle position accordingly and the throttle position is returned to the engine control module via the throttle position sensor. European On-Board Diagnostics (EOBD) compliant vehicles use at least two accelerator pedal position sensor and at least two throttle position sensors for redundancy. Failure of one circuit can easily be identified and vehicle operation will remain unaffected.