Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means there's a problem with the part of the car that helps separate oil from the air. It's like a special filter, and it needs to be warm to work right. If it's not getting warm, it might not work properly.
The engine oil separator heating circuit is responsible for heating the oil separator to ensure it functions correctly, especially in cold conditions. An open circuit indicates a break in the electrical path.
The P118C code is triggered when the Engine Control Module (ECM) detects an open circuit in the engine oil separator heating circuit. This could be due to a faulty heater element, wiring issues, or a problem with the ECM itself.
• Check Engine Light is on
• Poor engine performance
• Increased oil consumption
• Faulty oil separator heater element
• Damaged wiring or connectors
• Faulty Engine Control Module (ECM)
ECM: Engine Control Module
OBD-II: On-Board Diagnostics, Second Generation
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage.
• Test the oil separator heater element for continuity.
• Replace the faulty oil separator heater element.
• Repair or replace damaged wiring or connectors.
• Replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Wrench set
$150 - $500
Moderate
• BMW 3 Series
• BMW 5 Series
• BMW X5
• Regular maintenance checks
• Ensure proper oil levels
• Inspect wiring periodically
Sensor Issue
• Have the vehicle inspected by a professional.
• Avoid driving in extremely cold conditions until repaired.
Check with your vehicle manufacturer for warranty coverage on emissions-related components.
This code has been reported in vehicles with high mileage or those operating in cold climates.
Moderate – Should be addressed soon to prevent further engine issues.
Ignoring this issue could lead to increased emissions and potential engine damage.
• Engine at operating temperature
• Vehicle in a cold environment
The oil separator is typically located near the engine, often integrated into the crankcase ventilation system.
Q: Can I drive with a P118C code?
A: It's not recommended as it could lead to engine performance issues.
Q: How do I reset the check engine light after fixing the issue?
A: Use an OBD-II scanner to clear the code after repairs are made.
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