AutoCodes – Mercedes-Benz – P1642 Mercedes-Benz

P1642 Mercedes-Benz Code - Engine Control Module Incorrectly Coded

Quick Answer

P1642 Mercedes-Benz indicates Engine Control Module Incorrectly Coded. Common causes include Faulty Engine Control Module (ECM), Engine Control Module (ECM) harness is open or shorted, Engine Control Module (ECM) circuit poor electrical component. 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: P1642 Mercedes-Benz indicates Engine Control Module Incorrectly Coded.
Common causes: Common causes include Faulty Engine Control Module (ECM), Engine Control Module (ECM) harness is open or shorted, Engine Control Module (ECM) circuit poor electrical component.
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.

Save to My Repairs My Repairs

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

Code Popularity 3,773

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 04, 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 P1642 Mercedes-Benz Description

OBDII Code P1642 Mercedes-Benz - Engine Control Module Incorrectly Coded - AutoCodes.com — P1642 Mercedes-Benz Code - Engine Control Module Incorrectly Coded

What does this mean?

What are the Possible Causes of the DTC P1642 Mercedes-Benz?

Faulty Engine Control Module (ECM)
Engine Control Module (ECM) harness is open or shorted
Engine Control Module (ECM) circuit poor electrical component

How to Fix the DTC P1642 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 P1642 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 P1642 Mercedes-Benz code?

Need more information on how to fix the P1642 Mercedes-Benz code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1642 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 P1642 Mercedes-Benz Code

1. What does the OBDII code P1642 mean on a Mercedes-Benz?

P1642 indicates that the Engine Control Module (ECM) has been incorrectly coded or is not communicating correctly with other control modules in the vehicle.

2. What are the common symptoms of the P1642 code in a Mercedes-Benz?

Common symptoms include a check engine light, reduced engine performance, transmission shifting issues, or failure of certain vehicle functions.

3. What causes the P1642 code to appear?

This code is typically caused by incorrect ECM programming, a software mismatch, faulty ECM, or wiring/connectivity issues between the ECM and other modules.

4. Can a low battery trigger the P1642 code on a Mercedes-Benz?

Yes, a weak or failing battery can lead to communication errors or coding issues in the ECM, potentially triggering the P1642 code.

5. How do I fix the P1642 code on my Mercedes-Benz?

The fix may involve reprogramming or recoding the ECM using a Mercedes-Benz-specific diagnostic tool, inspecting wiring and connections, or replacing the ECM if it's faulty.

6. Do I need to replace the ECM if I get the P1642 code?

Not always. First, check for software updates or recoding options. ECM replacement should only be done if diagnostics confirm the module itself is defective.

7. Can I drive my Mercedes-Benz with the P1642 code active?

Driving with this code is not recommended, as it may lead to reduced performance, transmission issues, or further damage to the vehicle's systems.

8. Which diagnostic tool can I use to troubleshoot the P1642 code?

A Mercedes-Benz-specific diagnostic tool, such as the STAR Diagnostic System (SDS), is recommended for accurate troubleshooting and recoding.

9. How much does it cost to fix the P1642 code on a Mercedes-Benz?

Repair costs vary, but ECM recoding or reprogramming typically ranges from $150 to $300, while ECM replacement can cost upwards of $1,000 depending on the model.

10. Can an aftermarket ECM cause the P1642 code?

Yes, using a non-OEM or improperly programmed aftermarket ECM can result in coding mismatches and trigger the P1642 code.