How do I fix Shimano STEPS / EP error E021?

Turn the power off with the battery button, then on again. Make sure you are using the battery that came with the bike. If it continues, contact your place of purchase.

Shimano STEPS / EP error code

Shimano STEPS / EP error E021: Battery not supported by this drive unit

Q: Can I ride with Shimano STEPS / EP error E021?

Ride with caution. No assist, but the bike can be pedalled.

Medium severity Service soon

Can I ride home with this error?

Ride with caution. No assist, but the bike can be pedalled.

What it means

The connected battery is a STEPS-standard battery but is not supported by this drive unit, so assist is not provided.

Likely causes

Battery from a different STEPS system fitted

Symptoms

No assist
E021 shown

How to fix it

Turn the power off with the battery button, then on again.
Make sure you are using the battery that came with the bike.
If it continues, contact your place of purchase.

Still showing E021? The RideFixer app finds bike shops near you, so you know where to take it.

How urgent is it?

Use a supported battery; ask your dealer which one.

Applies to

STEPS E8000 (SC-E8000, SC-E6010)
STEPS E6100 / E5000 (SC-E6100)
STEPS E7000 (SC-E7000)

Did this help?

More Shimano STEPS / EP codes

E013 Drive unit firmware problem
E014 Speed sensor in the wrong position
E020 Battery and drive unit cannot communicate
E022 Battery does not meet system standards
E023 Electrical failure inside the battery
E024 Communication error with the bike system

All 22 Shimano STEPS / EP codes →