Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the part of the car that keeps oil from mixing with air isn't getting enough power to heat up properly.
The engine oil separator uses a heating element to prevent oil from freezing or gelling, ensuring proper separation. This code indicates that the heating circuit is not receiving enough voltage.
The P118B code is triggered when the Engine Control Module (ECM) detects a low voltage condition in the heating circuit of the engine oil separator. This component is crucial for maintaining proper oil and air separation in the crankcase ventilation system.
• Check engine light illuminated
• Potential oil leaks
• Reduced engine performance in cold weather
• Faulty oil separator heating element
• Wiring issues or poor electrical connections
• Blown fuse or relay associated with the circuit
ECM: Engine Control Module
OBD-II: On-Board Diagnostics II
• Use an OBD-II scanner to verify the code.
• Inspect the wiring and connections to the oil separator heater.
• Check the fuse and relay for the circuit.
• Replace the oil separator heating element if faulty.
• Repair or replace damaged wiring or connectors.
• Replace any blown fuses or faulty relays.
• OBD-II scanner
• Multimeter
• Basic hand tools
$100 - $300
Moderate
• BMW 3 Series
• BMW 5 Series
• Mini Cooper
• Regular maintenance checks
• Ensure electrical connections are secure
• Replace worn-out components promptly
Sensor Issue
• Have a professional inspect the vehicle if unsure.
• Avoid driving in extremely cold conditions until repaired.
Repairs may be covered under the vehicle's powertrain warranty.
This code is relatively common in vehicles with complex crankcase ventilation systems, especially in colder climates.
Moderate – Should be addressed soon to prevent further issues.
Ignoring this code can lead to increased emissions and potential engine damage.
• Engine at operating temperature
• Cold weather conditions
Typically located near the engine or integrated within the crankcase ventilation system.
Q: Can I drive with a P118B code?
A: It's possible, but not recommended as it can lead to further engine issues.
Q: What happens if I ignore this code?
A: Ignoring the code can lead to oil leaks and reduced engine performance.
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