dtc 801c20 BMW

The BMW DTC (Diagnostic Trouble Code) 801C20 typically refers to a communication error or malfunction in the electric parking brake system. Here's a detailed explanation in English:

DTC 801C20 – Electric Parking Brake: Signal Error

Full Description:

This fault code 801C20 is generally logged in the control unit related to the Electronic Parking Brake (EPB) or Dynamic Stability Control (DSC). It indicates that there is a signal error or communication issue between the parking brake control unit and other modules in the vehicle, most often the DSC or the Body Domain Controller (BDC).

Possible Error Message (seen in diagnostic tools):

• "Parking brake signal error"

• "Communication error with electronic parking brake"

• "Faulty signal from the parking brake control module"

Dtc 801c20 BMW - Common Causes:

• Damaged wiring or poor connection between the EPB control unit and other ECUs

• Corroded connectors

• Faulty EPB actuator

• Software issue or mismatch

• Low battery voltage or power supply disruption

• Faulty DSC or BDC control module

Symptoms:

• The parking brake may not engage or release properly.

• Warning lights on the dashboard (brake symbol, yellow or red).

• Possible error messages like "Parking brake malfunction" or "Drive moderately".

• Clicking sounds from the rear brakes without proper function.

Recommended Diagnostic Steps:

1. Scan all control modules for related DTCs – check if the fault is also logged in the DSC or BDC module.

2. Inspect wiring and connectors

3. Check battery voltage

4. Verify actuator function

5. Update or reprogram software for relevant modules if recommended by BMW.

Possible Fixes:

• Clean and secure all EPB-related connectors.

• Repair or replace any damaged wiring.

• Replace faulty actuators or the parking brake module if confirmed faulty.

• Perform a software update or reset adaptation using BMW’s ISTA software.