AutoCodes – Mercedes-Benz – P0578 Mercedes-Benz

P0578 Mercedes-Benz Code - Cruise Control Multi-Function Input 'A' Circuit Stuck

Quick Answer

The Engine Control Module (ECM) monitors the Cruise Control Multi-Function Input 'A'. Common causes include Faulty Cruise Control Function Switch, Cruise Control Function Switch harness is open or shorted, Cruise Control Function Switch circuit poor electrical connection. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

What it means: P0578 Mercedes-Benz indicates Cruise Control Multi-Function Input 'A' Circuit Stuck.
Common causes: Common causes include Faulty Cruise Control Function Switch, Cruise Control Function Switch harness is open or shorted, Cruise Control Function Switch circuit poor electrical connection.
Severity: Low - monitor the vehicle and repair when practical.
Can I drive?: The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 3,413

How popular is this code, among other codes? Low

Repair Importance Level

Low (Monitor) (1 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Apr 28, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0578 Mercedes-Benz Description

The Engine Control Module (ECM) monitors the Cruise Control Multi-Function Input 'A'. The ECM sets the OBDII code when the Cruise Control Multi-Function Input 'A' is not to factory specifications.

OBDII Code P0578 Mercedes-Benz - Cruise Control Multi-Function Input 'A' Circuit Stuck - AutoCodes.com — P0578 Mercedes-Benz Code - Cruise Control Multi-Function Input 'A' Circuit Stuck

What does this mean?

What are the Possible Causes of the DTC P0578 Mercedes-Benz?

Faulty Cruise Control Function Switch
Cruise Control Function Switch harness is open or shorted
Cruise Control Function Switch circuit poor electrical connection

How to Fix the DTC P0578 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 P0578 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 P0578 Mercedes-Benz code?

Need more information on how to fix the P0578 Mercedes-Benz code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0578 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 P0578 Mercedes-Benz Code

1. What does the OBDII code P0578 mean on a Mercedes-Benz?

P0578 indicates that the Cruise Control Multi-Function Input 'A' Circuit is stuck, which means there is an issue with the cruise control system receiving or processing inputs correctly.

2. What are the common symptoms of code P0578 in a Mercedes-Benz?

Symptoms may include the cruise control not engaging, the cruise control being stuck in one setting, or the cruise control system being completely inoperative. You may also notice the check engine light or a specific warning light on the dashboard.

3. What causes the P0578 code to trigger in a Mercedes-Benz?

Common causes include a malfunctioning cruise control switch, a short or open circuit in the wiring, a faulty brake or clutch pedal sensor, or, less commonly, issues with the powertrain control module (PCM).

4. Can I drive my Mercedes-Benz with a P0578 code?

Yes, you can drive the vehicle, but the cruise control system may not function properly. However, it's recommended to diagnose and repair the issue promptly to avoid further complications.

5. How do I diagnose the P0578 code on a Mercedes-Benz?

Start by checking the cruise control switch for proper operation. Inspect the wiring and connectors for damage, and use a scan tool to monitor the inputs and outputs of the cruise control system.

6. How do I fix the P0578 code on my Mercedes-Benz?

Repairs may include replacing a faulty cruise control switch, repairing damaged wiring or connectors, replacing a defective brake or clutch pedal sensor, or reprogramming or replacing the PCM if necessary.

7. How much does it cost to fix a P0578 code on a Mercedes-Benz?

Repair costs vary depending on the cause. Replacing a cruise control switch typically costs $150â€“$300, while wiring repairs or PCM replacement can cost significantly more.

8. Can a bad brake pedal sensor cause the P0578 code?

Yes, a faulty brake pedal sensor can cause the P0578 code, as it may send incorrect signals to the cruise control system, causing it to malfunction.

9. Will clearing the P0578 code solve the problem?

Clearing the code without addressing the root cause will not fix the issue. The code will likely return until the underlying problem is resolved.

10. Is the P0578 code specific to Mercedes-Benz vehicles?

No, the P0578 code is a generic OBDII code that can appear on any vehicle with a malfunction in the Cruise Control Multi-Function Input 'A' Circuit, but the diagnostics and repair steps may vary by manufacturer.