AutoCodes – Mercedes-Benz – P2138 Mercedes-Benz

P2138 Mercedes-Benz Code - Throttle/Pedal Position Sensor/Switch 'D'/'E' Voltage Correlation

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 Throttle/Pedal Position Sensor/Switch 'D'/'E', Throttle/Pedal Position Sensor/Switch 'D'/'E' harness is open or shorted, Throttle/Pedal Position Sensor/Switch 'D'/'E' 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: P2138 Mercedes-Benz indicates Throttle/Pedal Position Sensor/Switch 'D'/'E' Voltage Correlation.
Common causes: Common causes include Faulty Throttle/Pedal Position Sensor/Switch 'D'/'E', Throttle/Pedal Position Sensor/Switch 'D'/'E' harness is open or shorted, Throttle/Pedal Position Sensor/Switch 'D'/'E' 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 13,277

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
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P2138 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 P2138 Mercedes-Benz - Throttle/Pedal Position Sensor/Switch 'D'/'E' Voltage Correlation - AutoCodes.com — P2138 Mercedes-Benz Code - Throttle/Pedal Position Sensor/Switch 'D'/'E' Voltage Correlation

What does this mean?

What are the Possible Causes of the DTC P2138 Mercedes-Benz?

Faulty Throttle/Pedal Position Sensor/Switch 'D'/'E'
Throttle/Pedal Position Sensor/Switch 'D'/'E' harness is open or shorted
Throttle/Pedal Position Sensor/Switch 'D'/'E' circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P2138 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 = 0089 Voltage of Hall sensor 1 does not agree with the voltage of Hall sensor 2. (P2138)

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P2138 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 P2138 Mercedes-Benz code?

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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 P2138 Mercedes-Benz Code

1. What are the common symptoms of OBDII code P2138 in a Mercedes-Benz related to the Throttle/Pedal Position Sensor/Switch 'D'/'E' Voltage Correlation?

- Common symptoms include reduced engine power, stalling, rough idling, and potentially the vehicle going into limp mode.

2. What could cause the OBDII code P2138 to trigger in a Mercedes-Benz?

- The code P2138 may be triggered by a faulty throttle position sensor, pedal position sensor, wiring issues, or a problem with the electronic control module.

3. How can I diagnose the Throttle/Pedal Position Sensor/Switch 'D'/'E' Voltage Correlation issue in my Mercedes-Benz with code P2138?

- A thorough diagnostic scan using an OBDII scanner can help pinpoint the exact cause of the issue. Additionally, visually inspecting the sensors and their wiring for any signs of damage is recommended.

4. Is it safe to drive my Mercedes-Benz with the OBDII code P2138 related to the throttle position sensor issue?

- It is generally not advisable to drive the vehicle with this issue as it can lead to unsafe driving conditions and potential further damage to the engine.

5. Can I reset the OBDII code P2138 in my Mercedes-Benz without fixing the underlying issue?

- While you can clear the code temporarily, it is crucial to address the root cause of the problem to prevent it from recurring and potentially causing more severe issues.

6. What are some repair tips for fixing the Throttle/Pedal Position Sensor/Switch 'D'/'E' Voltage Correlation issue in a Mercedes-Benz with code P2138?

- Repair tips may include checking and cleaning sensor connections, replacing faulty sensors, inspecting and repairing damaged wiring, and ensuring proper reassembly of components.

7. How much does it typically cost to repair the throttle position sensor issue causing OBDII code P2138 in a Mercedes-Benz?

- The cost of repair can vary depending on the extent of the issue, the specific parts needing replacement, and labor costs. It is advisable to consult a professional mechanic for an accurate estimate.

8. Can I replace the throttle position sensor in my Mercedes-Benz myself to resolve code P2138?

- While it is possible to replace the throttle position sensor yourself, it is recommended to have the necessary expertise and tools to ensure proper installation and calibration to avoid further complications.

9. Will fixing the Throttle/Pedal Position Sensor/Switch 'D'/'E' Voltage Correlation issue with code P2138 improve my Mercedes-Benz's performance?

- Yes, resolving this issue can improve engine performance, throttle response, fuel efficiency, and overall drivability of your Mercedes-Benz.

10. How frequently does the OBDII code P2138 related to the throttle position sensor issue occur in Mercedes-Benz vehicles?

- The occurrence of code P2138 can vary, but it is not uncommon in Mercedes-Benz vehicles with throttle position sensor-related issues. Regular maintenance and inspections can help prevent such codes from appearing.