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P21F3 – BMW DTC

BMW DTC P21F3 – Cylinder 12 Injector ‘B’ Circuit High

DTC P21F3 meaning on BMW

The DTC P21F3 code on a BMW indicates an issue with the Cylinder 12 Injector ‘B’ Circuit High. This means that the Engine Control Module (ECM) has detected a high voltage condition in the circuit related to the fuel injector for cylinder 12.

BMW DTC P21F3 symptoms

Symptoms of the BMW DTC P21F3 code may include:

  • Check Engine Light illuminated
  • Engine misfires
  • Reduced engine performance
  • Increased fuel consumption

BMW DTC P21F3 causes

Possible causes of the BMW DTC P21F3 code include:

  • Faulty fuel injector for cylinder 12
  • Wiring or connector issues in the injector circuit
  • ECM software or hardware problems

BMW DTC P21F3 seriousness

Ignoring the DTC P21F3 code on a BMW can lead to further engine performance issues and potential damage. It is important to address this code promptly to prevent any long-term problems.

How to diagnose DTC P21F3 on BMW

To diagnose the DTC P21F3 code 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 cylinder 12 injector
  3. Test the fuel injector for cylinder 12 for proper operation
  4. Check for any ECM software updates or issues

How to fix DTC P21F3 on BMW

To fix the DTC P21F3 code on a BMW, you may need to:

  1. Replace the faulty fuel injector for cylinder 12
  2. Repair any wiring or connector issues in the injector circuit
  3. Update the ECM software if necessary

How to erase DTC P21F3 on BMW

To erase the DTC P21F3 code on a BMW, you can:

  1. Use a diagnostic scanner to clear the fault codes
  2. After fixing the underlying issue, reset the ECM by disconnecting the battery for a few minutes

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

← All BMW Diagnostic Trouble Codes

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