unu Scooter Service

Some important explanations about the unu scooter and how it works:

Power supply

Functionality Theory

MDB

Electronics section

1. Connector DC Converter: Transform main battery voltage to 12V-supply of scooter

2. AUX Battery: 12V-Pb-Battery: Necessary to start the scooter, Back-Up Battery to supply 12V-supply without main battery

3. CB-Battery: Back-Up Battery for scooter to supply scooter electronics without main battery

ECU: Motor Control Unit, integrated error code LED, blinks red if error appears

MDB: Middle Driver Board: Control unit where functions of the scooters are connected

Before disconnecting a connector of a unit on the unu, always remove the main battery first or/and disconnect the two connectors from the DC/DC converter.

Next, disconnect the red PLUS pole of the AUX battery.

Lastly, the 6-pin compact connector of the CB battery.

First reconnect the CB battery.

Then connect the positive terminal of the auxiliary battery.

Here the green LED on the right edge of the display should light up. As long as it is lit, the unu reboots itself internally and does not react to the key card or other interactions. Only after it goes out will the key card be recognised.

Finally, connect the two plugs of the DC voltage converter.

1. Check if AUX-Battery has 12V. 2. Check the 5A and 15A fuse 3. Remove to recharge AUX-Battery with external charger. Safety Cautions: Remove / Disconnect Main battery from slot #1 and CB-Battery

Source: Repair Manual 2.2.5 Sparepart SKU: SP-S-05-02-002

The unu scooter will charged the internal batteries with the power of the main battery.

The charging process starts when:

Check charging status on dashboard top left corner or version box. (RM 2.2.7)

Check charging by measuring the charging current and voltage. (RM 2.2.6)

If an unu is not worked on for more than 24 hours, we recommend putting it into sleep mode or disconnecting all power sources (main battery, DC/DC converter, aux battery, CB battery).

With a fully charged main battery and fully charged internal battery, we expect a standing time of approx. 12-14 days.

If the scooter is parked with only full internal batteries, we expect a standing time of 5-7 days.

The activation card (ACTIVATION) is only required after the MDB (control unit, front left) is replaced. The activation card is used to switch on the unu scooter after replacement and to start the activation process. The customer card is tuned in to the new MDB. After the activation process, the unu scooter will no longer recognise the activation card.

For additional information, see maintenance manual chapter 1.6.5.3 and 1.6.5.3.1.

The factory card (FACTORY) can be used to replace an MDB or a display during troubleshooting and to switch the unu scooter on and off independently without registration by us.

If a replaced unit is found to have fixed the problem, it can be activated with unu. The activation card is required for the activation process.

The unu shows different error codes on the display. It can show errors related to the internal batteries, to powertrain errors or to battery errors. A table with initial solutions can be found here. The table will be updated regularly with new solutions: unu scooter error code table

The fault is caused by a missing ground connection between the seat and the vehicle frame. The error B33 is caused by an unintentional discharge. To remedy this, a cable is pulled in between the seat and the vehicle frame. Detailed installation instructions can be found here: B33 Solution

The unu cannot be started with the customer card. It may be that the keycard is defective and the customer received a second one upon delivery. If both customer cards cannot start the scooter, it is very likely that the 12V battery is discharged. The check steps can be found here: unu scooter will not start part 1 diagnosis

The unu does not respond even though a full 12V aux battery has been installed. In this case, a blown fuse, a loose plug/pin or a damaged display or MDB control unit may be the cause. The check steps can be found here: Scooter does not start part 2 diagnosis

If a main battery is inserted into the scooter the first thing the scooter does is to recognize it. This means you can see the charge on the display.

If you close the seat the main battery will be activated. This means the scooter allows to use the full energy of the battery to drive or to charge the internal batteries.

(If the seat is open the main battery is not activated - but recognised - and you can not drive the scooter)

In the case the main batteries won't recognise or activate the main battery the most common issue is a defective connection between the MDB control unit and the display follows by a defective main battery.

Diagnose instruction can be found here: unu scooter does not recognise main batteries