E-Bike Error Codes: How to Look Yours Up

Your screen shows a number, or a letter and a number, and the bike has gone quiet or sulky. Write the code down exactly before you do anything else. The same number can mean different things on different bikes.

Why a code from the internet may be wrong for you

Codes aren't standard. Each maker writes its own list, and even one maker may have more than one list. The Trek help centre, for example, has separate headings for different systems, such as "Hyena eSystem Error Codes"¹. A code from a different system under the same maker can mean something else.

So the code on its own isn't enough. You need three things: the maker, the system or model, and the code.

Where makers keep their lists

Look in this order.

1. Your owner's manual. Many manuals have a table of codes near the back or in a troubleshooting chapter.
2. The maker's support or help pages. These are often searchable by model. One maker's help centre sorts its codes into a long list with the number first and the part second.
3. The maker's app. Some bikes pair with a phone app. Check your manual to see whether yours does and whether it shows codes.
4. Your dealer. A dealer can read what's behind a code when the printed list isn't enough.

Avoid pages from sellers, forums or repair blogs as your only source. They can disagree with the maker, and they may cover a different model year.

How a maker's line reads

A good line tells you the part, the fault and what to check. Take two lines from one maker's list: "66 | Battery - Battery is low" and "98 | HMI - Button is blocked or unresponsive"¹. The number comes first. The part follows, then the fault.

That layout helps. If the part named is the battery, you've got a different set of checks from a code naming the button pad. For the button code, the maker lists a damaged button or a broken connection as causes².

Warnings, errors and reminders

Not every code is a breakdown. The same maker splits its list under the headings "Warning" and "Critical Errors"¹. One entry is a maintenance reminder, with the number 113². Another is a heat entry where the system limits power². That's the bike limiting itself.

Check which kind your code is before you worry.

What the steps usually look like

Maker steps differ. Follow your manual's steps for any code, and don't take parts apart that the manual doesn't tell you to.

When you follow any maker's steps:

• Do them in the order given.
• Keep the safety notes that come with them.
• Stop and call the maker or a dealer if a step isn't in your manual for your model.

What not to do

Don't clear a code and carry on if it keeps coming back. Don't look for ways to switch off a warning or to change the bike's limits. And don't open the battery. The maker's help desk or a dealer is the right place for anything beyond your manual.

If your code isn't listed

Contact the maker with the code, the model name and the year. A photo of the screen helps. The icons page may help you describe a symbol. The parts page explains what a code can name.

A code may come from a sensor, such as the one that detects "the pedaling speed, the pedaling force, or both"³. It doesn't have to come from the screen.