Ride1Up 500 Series and Core-5: error 25 at power on and no motor power

You press the power button on a Ride1Up 500 Series or Core-5, the display wakes up with error 25, and the motor gives nothing on throttle or pedal assist. Code 25 on these bikes is the electronic brake shutoff, the sensor in each brake lever that cuts motor power while you brake (KD21C codes). Short answer: either a lever was squeezed while the bike powered on, or a lever, its sensor or its wire is damaged or not springing back. Ride1Up says holding either lever while pressing power will trigger error 25 (error 25).

Most likely cause

Each lever on these bikes has a small button style sensor. It stays inactive at rest, and when you squeeze the lever it signals the controller to cut motor power (error 25). If the controller sees that signal at start up, or all the time, it shows 25 and holds the motor off. Ride1Up's code table says this often follows a crash or a drop (KD21C codes), and the Core-5 manual describes code 25 as usually a sensor issue after a crash or drop (Core-5 manual).

Other causes to rule out

• A lever bent in a fall so it never fully returns to rest (error 25).
• Damage to the sensor wire or its connection at the internal controller (error 25).
• A different fault entirely. If there's no 25 on screen and the motor still won't drive, work through Ride1Up's Core-5 motor not working checks or our page on the Core-5 motor that spins then stops.

How to confirm

1. Turn the bike off. Check both levers sit in their resting position and spring back when you flick them.
2. Turn the bike on without touching either lever. If 25 is gone, it was just a squeezed lever at start up (error 25).
3. Look over both levers, the sensor wires along the handlebar and where they enter the frame for kinks, cuts or crushed sections. Ride1Up notes the damage isn't always obvious (error 25).
4. Ride1Up's test for which side is bad is to disconnect the brake sensor wires one at a time and see whether the code clears (KD21C codes). On these bikes the sensor wires connect at the internal controller behind a battery panel (controller access), so a shop may be quicker if you're not comfortable there. Reconnect everything when you're done.
5. Send photos of the levers and wires to Ride1Up support if the code stays (error 25).

Fix options

Restart without touching the levers (easy)

Most one off 25 codes clear this way.

Straighten or replace a damaged brake lever (easy to moderate)

Ride1Up sells left and right brake levers for the Core-5 (Core-5 parts) and for the 500 Series (500 Series parts). Swapping a lever on a mechanical brake means moving the cable and sensor wire across. See e-bike brakes and adjust mechanical disc brakes.

Replace the brake sensor (moderate)

The 500 Series parts list includes a brake sensor (500 Series parts). Ride1Up says the sensor comes out with two screws and a new one must have its wire routed through the brake body (error 25). Routing the wire to the controller means opening a battery panel.

Repair a damaged sensor wire (pro)

Splicing a sensor wire inside the frame is a shop job.

Parts

• Brake lever, left or right (Core-5 or 500 Series)
• Brake sensor (500 Series)

Videos

When to get a pro

• A lever that won't return after a crash, or a brake that feels different. Brakes come first.
• Any wire damage inside the frame or at the controller.
• If you aren't comfortable opening the battery panel. See check brake cut-off and throttle and when to call a pro.

Sources

• error 25, support.ride1up.com
• KD21C codes, support.ride1up.com
• Core-5 manual, ride1up.com
• Core-5 motor not working, support.ride1up.com
• controller access, support.ride1up.com
• Core-5 parts, ride1up.com
• 500 Series parts, ride1up.com
• Brake Sensor Test, youtube.com

Stuck after these checks? Find a shop near you.