AutoCodes – Mercedes-Benz – P0798 Mercedes-Benz

P0798 Mercedes-Benz Code - Pressure Control Solenoid 'C' Electrical

Quick Answer

This Diagnostic Trouble Code (DTC) is stored in the Engine Control Module (ECM) when a malfunction is detected with the pressure control solenoid circuit. Common causes include Faulty Transmission Fluid Pressure Solenoid, Transmission Fluid Pressure Solenoid harness is open or shorted, Transmission Fluid Pressure Solenoid 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: P0798 Mercedes-Benz indicates Pressure Control Solenoid 'C' Electrical.
Common causes: Common causes include Faulty Transmission Fluid Pressure Solenoid, Transmission Fluid Pressure Solenoid harness is open or shorted, Transmission Fluid Pressure Solenoid 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 3,476

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Dec 29, 2021

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0798 Mercedes-Benz Description

This Diagnostic Trouble Code (DTC) is stored in the Engine Control Module (ECM) when a malfunction is detected with the pressure control solenoid circuit. The mechanical condition of the transmission should be inspected prior to any electrical fault finding. An actuator test can be carried out on the pressure control solenoid and a current clamp can be used to monitor the condition of the winding. Electrical tests such as winding resistance, checking for short to power or short to ground can be carried out also. Normally the resistance of a solenoid winding is 10 to 25 Ohms.

OBDII Code P0798 Mercedes-Benz - Pressure Control Solenoid 'C' Electrical - AutoCodes.com — P0798 Mercedes-Benz Code - Pressure Control Solenoid 'C' Electrical

What does this mean?

What are the Possible Causes of the DTC P0798 Mercedes-Benz?

Faulty Transmission Fluid Pressure Solenoid
Transmission Fluid Pressure Solenoid harness is open or shorted
Transmission Fluid Pressure Solenoid circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P0798 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 P0798 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 P0798 Mercedes-Benz code?

Need more information on how to fix the P0798 Mercedes-Benz code? Get Access to Factory Service Manuals

Need Help with the 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 P0798 Mercedes-Benz Code

What does the OBDII code P0798 mean for a Mercedes-Benz?

The P0798 code indicates a problem with the electrical circuit of Pressure Control Solenoid 'C' in the transmission, which can affect shifting and overall performance.

What are the common symptoms of a P0798 code?

Common symptoms include erratic shifting, delayed engagement, slipping transmission, and potentially a check engine light.

What could cause the P0798 code to trigger?

Causes may include a faulty pressure control solenoid, wiring issues, poor electrical connections, or a malfunctioning transmission control module (TCM).

How can I diagnose a P0798 code?

To diagnose this code, use an OBDII scanner to confirm the code, inspect the wiring and connectors for damage, and test the solenoid's resistance and operation.

What are some potential repair solutions for a P0798 code?

Repairs may involve replacing the pressure control solenoid, repairing or replacing damaged wiring, or reprogramming or replacing the TCM if necessary.

Is it safe to drive with a P0798 code?

It is not recommended to drive with this code as it can lead to transmission issues, which may worsen and result in more expensive repairs.

How much does it typically cost to fix a P0798 code?

Repair costs can vary widely but may range from $100 for minor wiring repairs to $500 or more for solenoid replacement or TCM issues.

Can I reset the P0798 code without fixing the issue?

While you can reset the code, it is advisable to address the underlying issue, as the code will likely reappear and can lead to further transmission problems.

Will a transmission fluid change help with a P0798 code?

Changing the transmission fluid may help if the fluid is contaminated, but it won't resolve electrical issues related to the solenoid or wiring.