BYD ATTO 3 (e-Platform 3.0) C117009 EPB Switch Failure

C117009 indicates a failure involving the electronic parking brake (EPB) switch and its input circuit. The fault affects the electronic parking brake system, which monitors the switch command to determine when the driver requests parking brake application or release. The BYD ATTO 3 uses BYD’s e-Platform 3.0 architecture, with this generation introduced from 2022 and continuing onward.

Symptoms

• EPB warning light or message displayed
• Electronic parking brake may not apply
• Electronic parking brake may not release normally
• EPB switch command may be unresponsive
• Parking brake warning remains illuminated
• Vehicle may display a parking brake system fault
• C117009 stored in the EPB or related control module
• EPB-related functions may be restricted

Possible Causes

• Failed EPB switch
• Damaged or stuck switch mechanism
• Faulty switch electrical contacts
• Loose or damaged switch connector
• Poor terminal contact
• Open or short circuit in the switch wiring
• Damaged wiring around the centre-console switch area
• Low or unstable vehicle system voltage
• Communication fault involving the EPB control system
• EPB control-module fault

Diagnosis

Diagnosis should begin by confirming C117009 and checking the EPB switch input status using a suitable diagnostic system. The switch should be assessed for correct command recognition while the connector, terminals, wiring, and relevant power and ground circuits are inspected for faults. System voltage and communication with the EPB control system should also be verified before condemning the switch or control module. Accurate diagnosis is particularly important when parts availability and repair costs are considerations for New Zealand vehicle owners.

Accurately diagnosing this fault often requires manufacturer testing procedures, wiring diagrams, connector pinouts, specifications, and system calibration information. Access to the factory service manual significantly reduces diagnostic time and helps prevent unnecessary parts replacement.

Applicable Years

2022, 2023, 2024, 2025, 2026, onwards

To order the correct OEM Service and Repair Manual for your BYD ATTO 3, submit your request using the form below and our team will provide the ordering details.