Yamaha e-bike troubleshooting: PW series drive units and displays

This page is for riders whose e-bike uses a Yamaha PW series drive unit, such as the PWseries ST, PWseries S2, PWseries CE or C2, PW-X3 and PW-XM, with a Display A2, Display B, Display C or Interface X control. Many bike brands use Yamaha drives, so your bike brand's manual and dealer are your first stop. See also our systems overview.

Before you start

• Find your manual. Yamaha's owner's manual covers the drive units, displays, batteries and chargers listed above, and it has a troubleshooting section for each display (Yamaha owner's manual). Your bike brand may publish its own version.
• Know who to call. Yamaha says to contact your bike dealer or the bike's maker, and that Yamaha supports the bike maker behind the scenes (Yamaha e-Bike Systems FAQ). In the US, Yamaha's own bikes list a Customer Relations line on Yamaha's support page.
• Stop riding if something seems wrong. The manual says not to ride if there is any irregularity with the battery or the e-bike system.

Common problems and what to check

Assist feels weak right after you switch on

• Keep your feet off the pedals when you turn the display on, then wait about two seconds before riding. Yamaha says assist can feel weak if you skip this, and that it is not a fault (owner's manual).
• Walk assist stops on its own above 6 km/h, when you start pedaling, or when you pick Off mode, so this is also normal.
• If assist stays weak, see no pedal assist.

Assist cuts out or is limited

• A damaged speed sensor makes the system limit output and cut assist early, depending on the gear you are in (Yamaha FAQ). Look for a knocked sensor or a moved magnet, then see align speed sensor magnet.
• Yamaha says riders should not try to tune the system. Pedalwise does not cover tuning either.
• More steps: motor cuts out.

Won't charge, or charging pauses

• Charge at 15 to 25 °C (59 to 77 °F) on a flat, stable, dry surface out of direct sun and rain (owner's manual).
• If all four battery lamps flash slowly, the charger is in standby because the battery is too warm, for example right after a ride or in summer sun. Move the battery somewhere cool and let it rest.
• Keep the battery terminals clean, and do not grease them. Yamaha says this in both the manual and its FAQ.
• If the charger's power cable is damaged, stop using the charger and have it checked by a dealer.
• See battery won't charge and check your charger.

Range has dropped

• Yamaha suggests checking tire pressure and chain condition first, then making sure the battery was fully charged (Yamaha FAQ).
• Cold weather cuts range. Keeping the battery indoors before a ride helps.
• A worn out battery may need replacing. Your dealer can check it.
• See battery drains fast.

An error shows on the display

How the error shows depends on the control. On Display A2, "Er" alternates with the riding screen and a code appears. On Display B, "Er" alternates with the speed and a message appears. Display C shows a message. On Interface X, the assist mode light flashes red (owner's manual).

• Look up what your display shows in the troubleshooting section of your manual.
• If the manual's steps don't clear it, Yamaha says to have the bike inspected by a dealer as soon as possible.
• See also e-bike error codes.

After washing, rain or a dunk

• Don't aim a direct or high pressure water jet at the drive unit or battery (Yamaha FAQ).
• On bikes with a Multi Location battery, leave the battery in place while you wash so water stays out of the connector (owner's manual).
• If the bike went under water, get it out quickly, clean it and have a dealer check it. See e-bike got wet.

Firmware and updates

Yamaha's FAQ says updates are not needed and riders can't change the drive unit's software (Yamaha FAQ). If you think your bike needs an update, ask your dealer.

Storing your bike

Store the battery indoors in a dry place at 15 to 25 °C with one or two charge lamps lit. Check it monthly, and if one lamp is flashing, charge it for about 10 minutes. Don't leave it full or empty for long periods (Yamaha FAQ). See store your battery for winter.

Official help

• Yamaha owner's manual for PW series drive units, displays, batteries and chargers.
• Yamaha e-Bike Systems FAQ.
• Yamaha bicycles support for Yamaha branded bikes in the US.

When to get a pro

• Any error that stays after the steps in your manual.
• A damaged charger cable, battery or connector.
• A bike that has been under water.
• Anything inside the drive unit. Yamaha's manual says service, repair and maintenance should go to your dealer.

Sources

• Owner's manual, PW series e-Kit, Yamaha Motor (hosted by GASGAS)
• e-Bike Systems FAQ, Yamaha Motor
• Support, Yamaha Bicycles

Stuck after these checks? Find a shop near you.