Repair of the High-Voltage Power Supply System on a 2012 Renault Twizy Z.E.

The RENAULT Twizy Z.E. is a unique, ultra-compact electric city car (quadricycle) designed for the most convenient travel through a metropolis. The interior features an original two-seat “tandem” layout (the passenger seat is positioned directly behind the driver’s seat), which has made the body exceptionally narrow and maneuverable.

In Warsaw, this “portable” car offers significant advantages: thanks to its size, it moves easily through heavy traffic and parks where a regular car won’t fit, while its status as an electric vehicle allows it to legally use public transit lanes and entitles it to free parking (as of the publication of this article).

The model was produced in two versions:

• Twizy 45—a limited version (4.5 kW / 5 hp, top speed of 45 km/h), which falls under the category of light quadricycles (in some EU countries, it can be driven by individuals aged 14–16 who hold a moped license).
• Twizy 80—the full-fledged and most powerful version (13 kW / 17 hp, top speed up to 80 km/h), which requires a Category B or B1 driver’s license.

There is also a single-seat cargo version, the Twizy Cargo, which replaces the passenger seat with a 180-liter cargo compartment featuring a separate rear door.

It was the Twizy 80 version that came to our service center. This 2012 electric car has a total mileage of 39,000 km, of which the current owner has driven over 20,000 km. The car charges from a standard household outlet in 3.5 hours, and a full battery charge consistently provides a range of 80 km.

What issue did the owner report?

The problem was that after plugging the electric car in to charge, even though the battery successfully reached 100% charge, the car would not move.

The owner, an experienced driver, checked the basic components (handbrake, fuses) on his own and researched specialized forums, but was unable to identify the cause of the malfunction. Without specialized equipment or technical documentation to disassemble the electric vehicle’s powertrain, he made the best decision possible—he had the car towed to the specialists at STS.Electro.

Work Process

Repairing a modern electric vehicle requires a strict sequence of steps and adherence to safety protocols when working with high-voltage equipment:

1. Comprehensive Diagnostics: Initially, suspicion fell on the charger, but a check of its parameters showed it was fully functional.
2. Battery Removal and Troubleshooting: Our specialists consulted the technical manuals and electrical schematics for the Renault Twizy, after which they safely removed the battery pack. During the power circuit troubleshooting, a malfunction was identified: the relay-contactor was stuck in one position.

3. Parts Search: We do not replace components at random—thorough diagnostics allowed us to pinpoint the exact faulty part. Using the catalog numbers, we identified the original Renault part:

   OEM number of the relay-contactor: 29 4B 163 31R (markings on the housing: GER-150RN / 450V 150A / 120203-9354-00176).

4. Replacement and reassembly: We ordered the original relay, replaced it, reassembled the high-voltage unit according to factory specifications, and reinstalled the battery.

5. Testing and Vehicle Handover: After reassembly, we tested the power circuit and conducted a test drive. The electric vehicle is once again operating flawlessly.

The Renault Twizy owner was completely satisfied with the speed and quality of the work and left a positive review of STS.Electro on Google Maps:

"Thank you very much for the quick and high-quality repair of my Renault Twizy! The guys quickly found the cause of the malfunction, sourced the right part, and installed everything perfectly. I recommend this service to all electric vehicle owners!"

Need a high-quality repair for your electric car or hybrid? Contact STS.Electro!

If your electric vehicle experiences any malfunctions, don’t take a guess or risk your safety. Our specialists have the necessary equipment, manuals, and experience to tackle complex issues with high-voltage systems.

Having problems with your hybrid or electric car?

Schedule a repair or diagnostic check! We’ll perform a thorough diagnosis, identify the root cause, and get your car back on the road.