BMW DTC P31DB – H2 and High Pressure Injector ECM Boost Voltage Too High (Bank 2)
DTC P31DB meaning on BMW
DTC P31DB on a BMW refers to the High Pressure Injector ECM Boost Voltage Too High fault detected in Bank 2. This diagnostic trouble code indicates that the Engine Control Module (ECM) has detected that the boost voltage supplied to the high-pressure fuel injector in Bank 2 is exceeding the specified limits.
BMW DTC P31DB symptoms
Symptoms associated with BMW DTC P31DB may include rough engine operation, reduced engine performance, misfires, hesitation during acceleration, and in some cases, the Check Engine Light may illuminate on the dashboard.
BMW DTC P31DB causes
The common causes of BMW DTC P31DB include a faulty high-pressure fuel injector, wiring issues in the injector circuit, a malfunctioning Engine Control Module (ECM), or a problem with the power supply to the injector.
BMW DTC P31DB seriousness
Ignoring BMW DTC P31DB can lead to poor engine performance, reduced fuel efficiency, and potential damage to the engine components over time. It is recommended to address this issue promptly to prevent further complications.
How to diagnose DTC P31DB on BMW
To diagnose BMW DTC P31DB, a mechanic would typically use a diagnostic scanner to retrieve the fault codes stored in the ECM. They would then inspect the high-pressure injector in Bank 2, check the wiring for any damage or loose connections, and perform voltage tests to determine the cause of the high boost voltage.
How to fix DTC P31DB on BMW
Fixing BMW DTC P31DB usually involves replacing the faulty high-pressure fuel injector in Bank 2, repairing any damaged wiring or connectors, or addressing any issues with the Engine Control Module. Once the root cause is identified and resolved, the fault code should be cleared from the ECM memory.
How to erase DTC P31DB on BMW
To erase DTC P31DB on a BMW, a mechanic can use a diagnostic scanner to clear the fault code from the Engine Control Module’s memory. After the repair has been completed and the issue resolved, the fault code can be erased to turn off the Check Engine Light and ensure that the system is operating correctly.
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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