Throttle/Pedal Position Sensor/Switch ‘D’ Circuit Low
Table of contents
P2122 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
How do I fix code P2122 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 = 0077 (Accelerator pedal sensor). Hall sensor 1: Short circuit to ground or open circuit (P2122)
Cost of diagnosing the P2122 MERCEDES-BENZ code
The cost of diagnosing the P2122 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)
P2122 MERCEDES-BENZ Description
This fault code is stored in the Engine Control Module (ECM) when a fault is detected with the circuit monitoring throttle and accelerator pedal position. Both circuits are closely monitored for plausibility checks. The ECM can easily identify erroneous data by monitoring both circuits for an inconsistency between the throttle position sensor voltage and the accelerator pedal position sensor voltage. Normally potentiometers are used for both sensor circuits, however some manufacturers may use a hall effect sensor with a varying frequency depending on position. Another feature of modern vehicles is using multiple sensors for redundancy and fault analysis. This is where a technician would see data for accelerator pedal position sensor 1 and 2 or throttle position sensor 1 and 2. The voltages from these components can be inversely proportional or a stepped waveform with only output half the output of the other.