BMW DTC P120B – Crankcase Ventilation Diagnostic Valve Circuit Low
DTC P120B meaning on BMW
DTC P120B indicates a fault with the Crankcase Ventilation Diagnostic Valve Circuit Low in a BMW vehicle. This fault code is specific to the crankcase ventilation system, which is responsible for managing the pressure and emissions within the engine’s crankcase.
BMW DTC P120B symptoms
Common symptoms associated with DTC P120B in a BMW may include rough idling, decreased engine performance, increased fuel consumption, and the illumination of the check engine light on the dashboard.
BMW DTC P120B causes
The causes of DTC P120B in a BMW can vary, but common reasons include a faulty crankcase ventilation diagnostic valve, damaged wiring or connectors in the circuit, or issues with the engine control module (ECM).
BMW DTC P120B seriousness
While DTC P120B may not cause immediate drivability issues, it is important to address this fault code promptly to prevent potential damage to the engine and ensure optimal performance and fuel efficiency of the vehicle.
How to diagnose DTC P120B on BMW
To diagnose DTC P120B on a BMW, a mechanic would typically use a diagnostic scanner to retrieve the fault code and perform a thorough inspection of the crankcase ventilation system, including the diagnostic valve, wiring, and connectors. Testing the circuit for continuity and proper voltage levels is essential to pinpoint the exact cause of the fault.
How to fix DTC P120B on BMW
Fixing DTC P120B on a BMW may involve replacing the faulty crankcase ventilation diagnostic valve, repairing any damaged wiring or connectors, or reprogramming the engine control module if necessary. It is recommended to follow the manufacturer’s repair procedures and use genuine BMW parts for a reliable fix.
How to erase DTC P120B on BMW
After addressing the underlying issue causing DTC P120B on a BMW, the fault code can be erased using a diagnostic scanner. By clearing the code, the check engine light should turn off, indicating that the fault has been resolved. It is important to verify that the issue has been fixed before clearing the fault code.
Recommended tools & DTC Scanners for BMW
Best Diagnostic App for modern BMWs: BimmerLink
Recommended Bluetooth adapter for Bimmerlink: OBDLink CX
Cable adapter for Bimmerlink: Enet Cable USB Type C
For older BMWs we recommend: Autel AutoLink AL319 (2024 version)
Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter
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