BMW DTC P3420 – Cylinder 3 Deactivation/Intake Valve Control Circuit High
DTC P3420 meaning on BMW
The Diagnostic Trouble Code (DTC) P3420 for BMW indicates an issue with the Cylinder 3 Deactivation/Intake Valve Control Circuit being detected as high. This means that there is a problem with the control circuit responsible for deactivating the intake valve in cylinder 3 of the engine.
BMW DTC P3420 symptoms
Symptoms of DTC P3420 on a BMW may include:
- Check Engine Light illuminated on the dashboard
- Reduced engine performance or power
- Engine misfires or rough idling
- Decreased fuel efficiency
BMW DTC P3420 causes
Common causes of DTC P3420 on a BMW include:
- Faulty intake valve control solenoid
- Wiring or connector issues in the intake valve control circuit
- Engine control module (ECM) malfunction
- Mechanical issues with the intake valve itself
BMW DTC P3420 seriousness
While DTC P3420 may not always result in immediate drivability issues, it is important to address this code promptly to prevent potential engine damage or further complications. Ignoring this code can lead to reduced engine performance and efficiency.
How to diagnose DTC P3420 on BMW
To diagnose DTC P3420 on a BMW, a mechanic would typically perform the following steps:
- Use a diagnostic scanner to retrieve the fault code and freeze frame data
- Inspect the intake valve control solenoid and related wiring for any visible damage or corrosion
- Test the intake valve control circuit for proper voltage and continuity
- Check the engine control module (ECM) for any stored codes or malfunctions
How to fix DTC P3420 on BMW
To fix DTC P3420 on a BMW, the following steps may be taken:
- Replace the faulty intake valve control solenoid if necessary
- Repair any damaged wiring or connectors in the intake valve control circuit
- Address any ECM malfunctions or reprogram if needed
- Inspect and potentially repair or replace the intake valve if mechanical issues are detected
How to erase DTC P3420 on BMW
After addressing the underlying issue causing DTC P3420 on a BMW, the fault code can be erased using a diagnostic scanner. This will clear the code from the ECM’s memory and turn off the Check Engine Light. It is important to ensure that the repair has been successful before clearing the 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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