P042E – BMW DTC

BMW DTC P042E – EGR ‘A’ Control Stuck Open

DTC P042E meaning on BMW

The DTC P042E error code on a BMW indicates that the Engine Control Module (ECM) has detected an issue with the Exhaust Gas Recirculation (EGR) ‘A’ control circuit being stuck open. The EGR system is responsible for recirculating a portion of the engine’s exhaust gases back into the intake manifold to reduce emissions and control combustion temperatures.

BMW DTC P042E symptoms

Symptoms of the DTC P042E error code on a BMW may include:

  • Check Engine Light (CEL) illuminated on the dashboard
  • Decreased engine performance
  • Increased fuel consumption
  • Rough idling or stalling

BMW DTC P042E causes

The common causes of the DTC P042E error code on a BMW include:

  • Malfunctioning EGR valve
  • Wiring or connector issues in the EGR ‘A’ control circuit
  • Carbon buildup in the EGR system
  • Faulty ECM

BMW DTC P042E seriousness

Ignoring the DTC P042E error code on a BMW can lead to increased emissions, 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 P042E on BMW

To diagnose the DTC P042E error code on a BMW, you can perform the following steps:

  1. Use an OBD-II scanner to retrieve the specific fault code
  2. Inspect the EGR valve and associated components for any visible damage or carbon buildup
  3. Check the wiring and connectors in the EGR ‘A’ control circuit for continuity and proper connections
  4. Perform a smoke test to check for leaks in the EGR system

How to fix DTC P042E on BMW

To fix the DTC P042E error code on a BMW, you can try the following solutions:

  1. Clean or replace the EGR valve if it is found to be faulty
  2. Repair any damaged wiring or connectors in the EGR ‘A’ control circuit
  3. Clean out any carbon buildup in the EGR system
  4. Reset the ECM and clear the fault code

How to erase DTC P042E on BMW

To erase the DTC P042E error code on a BMW, you can use an OBD-II scanner to clear the fault code after addressing the underlying issue causing the fault code to appear. Once the fault code is cleared, the Check Engine Light should turn off.

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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