BMW DTC P1EFA – Hybrid/EV Battery Temperature Sensor ‘I’ Circuit/Open
DTC P1EFA meaning on BMW
DTC P1EFA on a BMW indicates an issue with the Hybrid/EV Battery Temperature Sensor ‘I’ Circuit/Open. This means that the sensor responsible for monitoring the temperature of the hybrid or electric vehicle battery is reporting an open circuit or a fault in the circuit.
BMW DTC P1EFA symptoms
Symptoms of the BMW DTC P1EFA may include:
- Check Engine Light illuminated
- Reduced hybrid or electric vehicle performance
- Increased fuel consumption
- Hybrid or electric vehicle not charging properly
BMW DTC P1EFA causes
Common causes of the BMW DTC P1EFA include:
- Faulty Hybrid/EV Battery Temperature Sensor ‘I’
- Open circuit in the sensor wiring
- Corrosion or poor connection in the sensor circuit
BMW DTC P1EFA seriousness
The seriousness of the BMW DTC P1EFA lies in the potential impact on the hybrid or electric vehicle’s performance and efficiency. Ignoring this fault can lead to further issues with the battery system and may result in reduced overall vehicle performance.
How to diagnose DTC P1EFA on BMW
To diagnose the DTC P1EFA on a BMW, a mechanic would typically:
- Use a diagnostic scanner to retrieve the fault code
- Inspect the Hybrid/EV Battery Temperature Sensor ‘I’ and its wiring for any visible damage or corrosion
- Test the sensor’s resistance and voltage readings to determine if it is functioning correctly
How to fix DTC P1EFA on BMW
To fix the DTC P1EFA on a BMW, the following steps may be taken:
- Replace the faulty Hybrid/EV Battery Temperature Sensor ‘I’
- Repair any open circuits or damaged wiring in the sensor circuit
- Clear the fault code and reset the vehicle’s system
How to erase DTC P1EFA on BMW
To erase the DTC P1EFA on a BMW, the fault code can be cleared using a diagnostic scanner or by disconnecting the vehicle’s battery for a few minutes. Once the issue has been fixed and the fault code 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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