P0603 Mercedes-Benz Code - Internal Control Module Keep Alive Memory Error
Quick Answer
Battery voltage is supplied to the ECM even when the ignition switch is turned OFF for the ECM memory function of the DTC memory, the air-fuel ratio feedback compensation value memory, the idle air volume learning value memory, etc. Common causes include Loose or poor battery terminal connection, Low battery charge, ECM power supply circuit is open or shorted. 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
- P0603 Mercedes-Benz indicates Internal Control Module Keep Alive Memory Error.
- Common causes
- Common causes include Loose or poor battery terminal connection, Low battery charge, ECM power supply circuit is open or shorted.
- 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.
Code P0603 Mercedes-Benz Description
What are the Possible Causes of the DTC P0603 Mercedes-Benz?
- Loose or poor battery terminal connection
- Low battery charge
- ECM power supply circuit is open or shorted
- ECM Programing
- Faulty ECM
How to Fix the DTC P0603 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.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0603 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.
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Frequently Asked Questions about P0603 Mercedes-Benz Code
1. What does the OBDII code P0603 mean for a Mercedes-Benz?
P0603 indicates an Internal Control Module Keep Alive Memory (KAM) Error, where the control module cannot retain stored data when the vehicle is turned off.
2. What are common symptoms of code P0603 in a Mercedes-Benz?
Symptoms may include erratic engine performance, stalling, difficulty starting, or the Check Engine Light illuminating.
3. What causes the P0603 code in a Mercedes-Benz?
Common causes include a weak or damaged battery, faulty alternator, poor electrical connections, or a malfunctioning control module.
4. Can a weak battery trigger the P0603 code?
Yes, a weak or failing battery can cause the control module to lose its stored settings, leading to the P0603 error.
5. How do you diagnose the P0603 code in a Mercedes-Benz?
Diagnosis typically involves checking battery voltage, inspecting electrical connections, testing the alternator, and scanning for related error codes.
6. Is it safe to drive a Mercedes-Benz with code P0603?
While the car may still run, driving with this code can lead to erratic performance or stalling, making repairs advisable.
7. How can you fix the P0603 code on a Mercedes-Benz?
Repairs may include replacing the battery, fixing wiring issues, updating the control module software, or replacing the module if faulty.
8. Can a loose ground connection cause the P0603 code?
Yes, a loose or corroded ground connection can disrupt the power supply to the control module and trigger this code.
9. Does code P0603 always mean the control module is defective?
No, the code can also be caused by external factors like battery issues or wiring problems. The module should only be replaced after thorough diagnosis.
10. Can updating the control module software resolve the P0603 code?
In some cases, updating the software can fix issues with memory retention, but other causes should be ruled out first.
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