P0203 Mercedes-Benz Code - Injector Circuit/Open Cylinder 3
Quick Answer
This fault code is stored in the Engine Control Module (ECM) when the injector control circuit does not behave as expected. Common causes include Faulty Fuel Injector #3, Fuel Injector 3 harness is open or shorted, Fuel Injector #3 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
- P0203 Mercedes-Benz indicates Injector Circuit/Open Cylinder 3.
- Common causes
- Common causes include Faulty Fuel Injector #3, Fuel Injector 3 harness is open or shorted, Fuel Injector #3 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.
Code P0203 Mercedes-Benz Description
What are the Possible Causes of the DTC P0203 Mercedes-Benz?
- Faulty Fuel Injector #3
- Fuel Injector 3 harness is open or shorted
- Fuel Injector #3 circuit poor electrical connection
- Faulty Engine Control Module (ECM)
How to Fix the DTC P0203 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 P0203 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 P0203 Mercedes-Benz code?
Need more information on how to fix the P0203 Mercedes-Benz code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P0203 Mercedes-Benz code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about P0203 Mercedes-Benz Code
1. What does the OBDII code P0203 mean on a Mercedes-Benz?
P0203 indicates an issue with the injector circuit for cylinder 3, specifically an open circuit or malfunction.
2. What are the common symptoms of a P0203 code in a Mercedes-Benz?
Symptoms include rough idling, engine misfires, reduced power, poor fuel efficiency, and in some cases, a check engine light.
3. What causes the P0203 code on a Mercedes-Benz?
Common causes include a faulty fuel injector, damaged wiring or connectors in the cylinder 3 injector circuit, or a malfunctioning engine control module (ECM).
4. How do I diagnose a P0203 code on a Mercedes-Benz?
Start by inspecting the cylinder 3 injector wiring and connectors for damage or corrosion. Then test the injector itself and the voltage signal from the ECM.
5. Can I drive my Mercedes-Benz with a P0203 code?
Driving with this code is not recommended, as it can cause further damage to the engine and lead to poor performance or increased emissions.
6. How do I fix the P0203 code on a Mercedes-Benz?
Repair or replace any damaged wiring or connectors, replace the faulty injector, or reprogram/replace the ECM if necessary.
7. How much does it cost to fix a P0203 code on a Mercedes-Benz?
Repair costs vary but typically range from $100 to $500, depending on whether the issue is wiring, the injector, or the ECM.
8. Can a dirty injector cause a P0203 code on a Mercedes-Benz?
While uncommon, a dirty or clogged injector can contribute to injector circuit issues. Cleaning the injector may help if the issue is minor.
9. Will clearing the P0203 code solve the problem permanently?
Clearing the code without addressing the underlying issue will only temporarily remove the check engine light. The code will likely return.
10. What tools are needed to troubleshoot a P0203 code on a Mercedes-Benz?
Basic tools include an OBDII scanner, a multimeter to test wiring and voltage, and possibly an injector tester to verify injector functionality.
Discuss the causes and fixes for P0203 Mercedes-Benz OBDII Code
Code P0203 Mercedes-Benz comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
