BYD Dolphin Comfort Mk1

A known issue across BYD's EV range. The DC-DC converter that charges the small 12V battery from the main pack can behave inconsistently, particularly after OTA software updates or extended parking periods of a week or more. Symptoms include slow dashboard startup, random error messages, and the car refusing to power on. BYD has acknowledged the issue and released software updates to improve DC-DC converter management. Replacement of the 12V battery itself costs around €120-180, but if the DC-DC converter module needs attention, costs can reach €260. A battery maintainer during long storage periods is recommended.

The BYD Dolphin's infotainment system can experience interface freezes, Bluetooth and wireless CarPlay instability, and user profiles resetting after OTA updates. Some owners report that after an OTA update, activating climate control via the app puts the car in a quasi-ready state with interior lighting turning on while the car remains locked. Most issues are resolved through subsequent OTA updates or a factory reset of the infotainment system. BYD service centres can flash firmware directly if needed, recovering roughly 95% of issues without hardware replacement. The cost is typically €0 under warranty or up to €150 for a diagnostic visit and manual firmware update out of warranty.

The forward collision warning and automatic emergency braking system can trigger unnecessarily, particularly when approaching roundabouts or when vehicles ahead turn off the road. Owners report five loud beeps with red dashboard alerts even when no obstacle is present. The child presence detection system also generates false alarms, especially when owners remain in parked vehicles. The phantom braking events can be reduced by adjusting ADAS sensitivity settings (setting Predictive Collision Warning and Front Cross Traffic Braking to Off). Software calibration at a BYD service centre costs €60-180 and can improve sensor behaviour. BYD has been refining the algorithms through OTA updates.

Some Dolphins have triggered EPS fault messages with a steering warning light and momentary steering stiffness. In most cases this is a software calibration issue resolved by an OBD diagnosis and sensor realignment at a cost of around €60-180. In rare cases, the steering column controller may need replacement. This is worth noting because BYD recalled 96,714 Dolphins produced in China (February-December 2023) for a CEPS controller defect that could cause micro-cracks and overheating. While the recall was issued in China, European-spec Dolphins from the same production period should be verified with BYD using the VIN.

The BYD Dolphin weighs around 1,520 kg due to the battery pack, which puts more stress on suspension components than comparable ICE hatchbacks. Owners report crunching sounds on cobblestones and thumping over potholes. Common causes include panel clips not fully seated, door seals needing adjustment, and stabilizer bar connecting rod wear. Solutions range from lubricating seals and re-seating clips (€50-100) to replacing stabilizer link rods (€150-360 including alignment). The issue is primarily cosmetic rather than safety-related.

This is a design characteristic rather than a fault, but it significantly affects usability for long-distance winter driving. The BYD Dolphin's LFP battery is more sensitive to cold than NMC batteries, and below 10 degrees DC charging speed drops substantially. Below 0 degrees, the battery may accept only 10-20 kW instead of the 88 kW maximum. No BYD model sold in Europe currently offers automatic battery preconditioning before arriving at a DC charger. The only workaround is highway driving for 30-45 minutes before stopping to DC charge, which warms the battery naturally. This is not a repair cost but can make the car impractical for winter road trips with frequent charging stops.