AutoCodes – Mercedes-Benz – P0846 Mercedes-Benz

P0846 Mercedes-Benz Code - Transmission Fluid Pressure Sensor/Switch 'B' Circuit Range/Performance

Quick Answer

The Transmission Control Module (TCM) monitors the Transmission Fluid Pressure Sensor/Switch signal. Common causes include Faulty Transmission Fluid Pressure Sensor/Switch 'B', Transmission Fluid Pressure Sensor/Switch 'B' harness is open or shorted, Transmission Fluid Pressure Sensor/Switch 'B' 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: P0846 Mercedes-Benz indicates Transmission Fluid Pressure Sensor/Switch 'B' Circuit Range/Performance.
Common causes: Common causes include Faulty Transmission Fluid Pressure Sensor/Switch 'B', Transmission Fluid Pressure Sensor/Switch 'B' harness is open or shorted, Transmission Fluid Pressure Sensor/Switch 'B' 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 3,732

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 May 10, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0846 Mercedes-Benz Description

The Transmission Control Module (TCM) monitors the Transmission Fluid Pressure Sensor/Switch signal. The TCM sets the OBDII code when the Transmission Fluid Pressure Sensor/Switch is not to factory specifications.

OBDII Code P0846 Mercedes-Benz - Transmission Fluid Pressure Sensor/Switch 'B' Circuit Range/Performance - AutoCodes.com — P0846 Mercedes-Benz Code - Transmission Fluid Pressure Sensor/Switch 'B' Circuit Range/Performance

What does this mean?

What are the Possible Causes of the DTC P0846 Mercedes-Benz?

Faulty Transmission Fluid Pressure Sensor/Switch 'B'
Transmission Fluid Pressure Sensor/Switch 'B' harness is open or shorted
Transmission Fluid Pressure Sensor/Switch 'B' circuit poor electrical connection

How to Fix the DTC P0846 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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0846 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 P0846 Mercedes-Benz code?

Need more information on how to fix the P0846 Mercedes-Benz code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0846 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 P0846 Mercedes-Benz Code

1. What does the OBDII code P0846 mean in a Mercedes-Benz?

P0846 indicates an issue with the Transmission Fluid Pressure Sensor/Switch 'B' circuit, specifically that its readings are out of the expected range or performance parameters.

2. What are the common symptoms of code P0846 in a Mercedes-Benz?

Symptoms may include erratic shifting, transmission staying in limp mode, delayed engagement, slipping gears, or the illumination of the check engine light.

3. What causes code P0846 in a Mercedes-Benz?

Common causes include a faulty transmission fluid pressure sensor/switch, damaged wiring or connectors, low or dirty transmission fluid, or internal transmission issues.

4. Can I still drive my Mercedes-Benz with the P0846 code?

Driving with this code is not recommended as it can lead to further transmission damage or unsafe driving conditions due to shifting issues.

5. How is code P0846 diagnosed in a Mercedes-Benz?

A technician will typically inspect the transmission fluid, check the wiring and connectors for damage, test the pressure sensor/switch, and possibly perform a transmission pressure test.

6. How do I fix code P0846 in a Mercedes-Benz?

Repairs may include replacing the transmission fluid pressure sensor/switch, repairing damaged wiring or connectors, flushing and replacing the transmission fluid, or addressing internal transmission problems.

7. Can low transmission fluid cause the P0846 code?

Yes, low or contaminated transmission fluid can cause incorrect pressure readings from the sensor, triggering the P0846 code.

8. Is the P0846 code specific to Mercedes-Benz vehicles?

No, the P0846 code is a generic OBDII code applicable to many vehicles, but the exact symptoms and repair processes may vary by make and model.

9. How much does it cost to fix code P0846 on a Mercedes-Benz?

The repair cost depends on the root cause, ranging from $100 for a fluid replacement to $500 or more for sensor replacement or internal transmission repairs.

10. Can a failing transmission pressure sensor damage my Mercedes-Benz?

Yes, a faulty sensor can cause the transmission to operate improperly, potentially leading to further damage if not addressed promptly.