BMW DTC P0850 – Park/Neutral Switch Input Circuit
DTC P0850 meaning on BMW
The DTC P0850 code on a BMW indicates a malfunction in the Park/Neutral switch input circuit. This switch, also known as the Transmission Range Sensor (TRS) or Neutral Safety Switch, is responsible for detecting the gear position of the transmission. The switch sends signals to the engine control module (ECM) to ensure the vehicle is in Park or Neutral before starting the engine.
BMW DTC P0850 symptoms
Symptoms of a DTC P0850 on a BMW may include:
- Difficulty starting the vehicle
- Inability to start the engine
- Incorrect gear display on the instrument cluster
- Vehicle stalling when shifting gears
BMW DTC P0850 causes
Common causes of a DTC P0850 on a BMW include:
- Faulty Park/Neutral switch
- Wiring or connector issues in the switch circuit
- ECM software or hardware problems
BMW DTC P0850 seriousness
The seriousness of a DTC P0850 code on a BMW can vary. While the vehicle may still operate, it is crucial to address the issue promptly to prevent potential safety hazards or further damage to the transmission system.
How to diagnose DTC P0850 on BMW
To diagnose a DTC P0850 on a BMW, follow these steps:
- Use a diagnostic scanner to retrieve the fault codes stored in the ECM.
- Inspect the Park/Neutral switch and its wiring for any visible damage or corrosion.
- Test the switch for proper functionality using a multimeter.
- Check the ECM for any related error codes or software issues.
How to fix DTC P0850 on BMW
To fix a DTC P0850 on a BMW, consider the following solutions:
- Replace the faulty Park/Neutral switch with a new one.
- Repair or replace any damaged wiring or connectors in the switch circuit.
- If the ECM is at fault, reprogram or replace it as necessary.
How to erase DTC P0850 on BMW
To erase a DTC P0850 code on a BMW, you can:
- Use a diagnostic scanner to clear the fault codes stored in the ECM.
- After making the necessary repairs, perform a test drive to ensure the code does not reappear.
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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