P108B – BMW DTC

BMW DTC P108B – H2-Rail Pressure Regulator Circuit High

DTC P108B meaning on BMW

DTC P108B on a BMW refers to the H2-Rail Pressure Regulator Circuit High. This diagnostic trouble code indicates that the engine control module has detected a high voltage condition in the circuit responsible for controlling the H2-rail pressure regulator.

BMW DTC P108B symptoms

Symptoms of DTC P108B on a BMW may include:

  • Check Engine Light illuminated
  • Reduced engine performance
  • Engine stalling or hesitation
  • Increased fuel consumption

BMW DTC P108B causes

Common causes of DTC P108B on a BMW include:

  • Faulty H2-rail pressure regulator
  • Wiring or connector issues in the circuit
  • Defective engine control module

BMW DTC P108B seriousness

DTC P108B should be addressed promptly as it can lead to engine performance issues and potentially cause further damage if left unresolved.

How to diagnose DTC P108B on BMW

To diagnose DTC P108B on a BMW, you can perform the following steps:

  1. Use a diagnostic scanner to retrieve the fault codes
  2. Inspect the wiring and connectors related to the H2-rail pressure regulator circuit
  3. Test the H2-rail pressure regulator for proper operation
  4. Check the engine control module for any faults

How to fix DTC P108B on BMW

To fix DTC P108B on a BMW, you may need to:

  1. Replace the faulty H2-rail pressure regulator
  2. Repair any damaged wiring or connectors in the circuit
  3. Reset the engine control module after making repairs

How to erase DTC P108B on BMW

To erase DTC P108B on a BMW, you can use a diagnostic scanner to clear the fault codes stored in the engine control module. Once the codes are cleared, you can verify if the issue has been resolved by driving the vehicle and checking for any reoccurrence of 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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