BMW DTC P31EF – H2 and High Pressure Injector ECM, Switchover Fuel Mode Circuit Low (Bank 1)
DTC P31EF meaning on BMW
The DTC P31EF on a BMW refers to the High Pressure Injector ECM, Switchover Fuel Mode Circuit Low (Bank 1) fault code. This code indicates an issue with the high-pressure fuel injector circuit on Bank 1 of the engine control module (ECM).
BMW DTC P31EF symptoms
Symptoms of the BMW DTC P31EF may include rough idling, engine misfires, reduced engine performance, decreased fuel efficiency, and in some cases, the vehicle may go into a limp mode where power is limited.
BMW DTC P31EF causes
Common causes of the BMW DTC P31EF code include a faulty high-pressure fuel injector, wiring issues in the fuel injector circuit, a malfunctioning ECM, or a problem with the fuel pressure sensor.
BMW DTC P31EF seriousness
Ignoring the DTC P31EF on a BMW can lead to poor engine performance, reduced fuel efficiency, and potential engine damage over time. It is important to address this issue promptly to prevent further complications.
How to diagnose DTC P31EF on BMW
To diagnose the DTC P31EF on a BMW, a mechanic would typically use a diagnostic scanner to retrieve the fault code and then perform a visual inspection of the high-pressure fuel injector and its wiring. They may also conduct tests on the fuel injector circuit and the ECM to pinpoint the exact cause of the issue.
How to fix DTC P31EF on BMW
Fixing the DTC P31EF on a BMW may involve replacing the faulty high-pressure fuel injector, repairing any damaged wiring in the circuit, or addressing any ECM issues. It is recommended to follow the manufacturer’s diagnostic and repair procedures to ensure a proper fix.
How to erase DTC P31EF on BMW
Once the underlying issue causing the DTC P31EF on a BMW has been resolved, the fault code can be cleared using a diagnostic scanner. By clearing the code, the ECM will reset and monitor the system for any recurring issues.
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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