AutoCodes – Mercedes-Benz – P2122 Mercedes-Benz

P2122 Mercedes-Benz Code - Throttle/Pedal Position Sensor/Switch 'D' Circuit Low

Quick Answer

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. 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: P2122 Mercedes-Benz indicates Throttle/Pedal Position Sensor/Switch 'D' Circuit Low.
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.

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Code Popularity 9,105

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Sep 08, 2019

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code 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.

OBDII Code P2122 Mercedes-Benz - Throttle/Pedal Position Sensor/Switch 'D' Circuit Low - AutoCodes.com — P2122 Mercedes-Benz Code - Throttle/Pedal Position Sensor/Switch 'D' Circuit Low

What does this mean?

What are the Possible Causes of the DTC P2122 Mercedes-Benz?

Faulty Accelerator Pedal Position Sensor
Accelerator Pedal Position Sensor harness is open or shorted
Accelerator Pedal Position Sensor circuit poor electrical connection

How to Fix the DTC P2122 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.

What does this mean?

Code Tech Notes

Mercedes Benz Code = 0077 (Accelerator pedal sensor). Hall sensor 1: Short circuit to ground or open circuit (P2122)

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P2122 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.

Need more information about the P2122 Mercedes-Benz code?

Need more information on how to fix the P2122 Mercedes-Benz code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P2122 Mercedes-Benz code diagnosed by a professional: Find a repair shop in your area

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P2122 Mercedes-Benz Code

1. What are the common symptoms of OBDII code P2122 on a Mercedes-Benz?

- Common symptoms include reduced engine power, throttle response issues, and the vehicle going into limp mode.

2. What does the OBDII code P2122 on a Mercedes-Benz indicate?

- The code P2122 indicates a low voltage condition in the Throttle/Pedal Position Sensor/Switch 'D' circuit.

3. What are the potential causes of OBDII code P2122 on a Mercedes-Benz?

- Possible causes include a faulty throttle position sensor, damaged wiring or connectors in the circuit, or a problem with the engine control module.

4. How serious is the OBDII code P2122 on a Mercedes-Benz?

- This code is considered serious as it can affect the drivability of the vehicle and may lead to safety concerns if not addressed promptly.

5. Can I continue driving my Mercedes-Benz with the OBDII code P2122 present?

- It is not recommended to continue driving with this code active, as it can cause performance issues and potentially lead to further damage if left unresolved.

6. How can I diagnose the OBDII code P2122 on my Mercedes-Benz?

- Diagnosing this code typically involves using a scan tool to read the code, checking the throttle position sensor's voltage, inspecting wiring and connectors, and testing the sensor's operation.

7. What is the typical repair for OBDII code P2122 on a Mercedes-Benz?

- The typical repair involves replacing the faulty throttle position sensor, repairing any damaged wiring or connectors, and clearing the code from the engine control module.

8. Are there any DIY tips for addressing OBDII code P2122 on a Mercedes-Benz?

- While some may attempt to replace the throttle position sensor themselves, it is recommended to have the issue diagnosed and repaired by a qualified mechanic to ensure proper functioning.

9. How much does it cost to fix OBDII code P2122 on a Mercedes-Benz?

- The cost of fixing this issue can vary depending on the root cause, but it may involve parts and labor expenses ranging from a few hundred to over a thousand dollars.

10. Can resetting the OBDII code P2122 on a Mercedes-Benz make it go away permanently?

- Simply resetting the code without addressing the underlying issue will likely cause it to reappear once the problem is detected again. It is crucial to fix the root cause to resolve the code permanently.