BYD powertrain fault warning light: what it means
What the powertrain fault warning light means on BYD EV and DM-i models, and why the handbook advises against continuing to drive.
Safety and service note
What this means
The powertrain fault warning light comes on when the drive system fails. According to the official handbook, this light is steady on when the ignition is switched on, or it can turn on during driving. Either way, the handbook's own caution is direct: try not to drive the vehicle when this warning light is on.
What causes it
A powertrain fault can involve the motor, the drive-unit electronics, or the connection between the high-voltage system and the motor; because DM-i models combine an engine with electric drive components, the fault could originate in either part of the system. The handbook does not attribute the fault to a single cause, which is why professional diagnosis is needed rather than guesswork.
What to do
Contact a BYD authorised dealer or service provider to check the problem as soon as possible, and avoid driving the vehicle in the meantime if practical. Do not attempt to diagnose or work on the motor, drive unit, or related high-voltage components yourself.
Important
Contact a BYD authorised dealer or service provider to check the problem as soon as possible, and avoid driving the vehicle in the meantime if practical. Do not attempt to diagnose or work on the motor, drive unit, or related high-voltage components yourself.
Frequently asked questions
Can I keep driving with the powertrain fault light on?
The official handbook advises trying not to drive the vehicle while this light is on, and to contact BYD service as soon as possible.
Does this light mean the motor itself has failed?
Not necessarily -- it covers the drive system broadly, which can include the motor, drive-unit electronics, or their connection to the high-voltage system; a technician needs to diagnose the exact cause.
Is this different on DM-i (hybrid) models compared to EV models?
DM-i models combine an engine with electric drive components, so a powertrain fault could originate in either part; the warning light itself is used the same way across both.
What if the light comes on only briefly then goes off?
A warning light that lights up briefly during operation does not necessarily indicate a problem, per the handbook's own general guidance, but any light that stays on should still be checked.
Is it safe to inspect the drive system myself?
No. The drive system includes high-voltage components and should only be inspected or repaired by an authorised BYD technician.
Does this apply to all current BYD EV and DM-i models?
Yes -- the powertrain fault warning light and the advice to avoid driving while it is on are described consistently across BYD's current range.
Sources for this guide
This guide is for informational purposes only. Always consult an authorised service centre for safety-critical repairs. AutoTechHelp is not liable for any damage resulting from the use of this information.