Bosch Purion Display Settings

Bosch Purion Display Settings

The Bosch Purion is a minimalist on-board computer for e-bikes with Bosch motor systems. The Purion allows you to view and change settings related to your e-bike's functionality.

In this article, we'll explain how to use the Purion's controls and how to access different Purion display settings.

What is the Bosch Purion display?

The Purion is a small on-board computer for e-bikes with Bosch motor systems. The Purion's minimalistic design provides a clean-looking cockpit and a simple user interface.

Where is the Purion display located?

The Purion display is located on the left side of the handlebars. It is positioned so that the rider can easily access its "+" and "-" buttons while riding using their left thumb.

How do you use the Purion display to control the bike's motor system?

Turning the Purion Display On

Press the Power button, which is located on the top side of the Purion display. You'll know the Purion is on when white backlighting appears, along with your speed, trip statistics, and a battery status icon.

Turning the Bike's Lights On

If you have a GSD Gen 2, your bike lights are set to "always on", which means you only need to turn on your Purion display in order to use your front and rear lights.

On other bikes, slide the switch on the rear of the Valo light to the right. Then, press and hold the Purion's "+" button for 3 seconds. A light icon will appear, indicating that the bike's front and rear lights are on.

If you'd like to ride with the rear light on but the front Valo light off, manually turn off the Valo light by sliding the switch on the rear of the Valo to the left.

Switching Between E-Assist Modes

To switch between modes, single-press the "+" and "-" buttons on the Purion display to cycle through Off, Eco, Tour, Sport, and Turbo until you reach your desired level.

Eco provides the lowest level of e-assist, whereas Turbo delivers the highest level.

Using the Walk Assist Mode

Your bike's Bosch motor system includes a Walk Assist mode. This mode provides a little bit of assistance to a person walking alongside and pushing the bike.

To activate Walk Assist, make sure the bike is in one of the four e-assist modes (Walk Assist will not turn on if the motor system is set to "Off"). Then, short press the Walk Assist button on the bottom side of the Purion display. An icon reading "WALK+" will appear on the screen. Immediately press the "+" button for 3 seconds and keep holding the button to use Walk Assist.

How do you access different Purion display settings?

When the Purion boots up, you will see three rows on the screen:

  • Top row: speed
  • Middle row: trip statistics (shows battery range estimate by default)
  • Bottom row: battery icon (each bar represents approximately 20% of charge remaining)

By using specific combinations of the "+" and "-" buttons, you can control what information is displayed on the Purion's screen.

Switching Between Metric and Imperial Units

To change your Purion display's units from km to mi (or vice versa), hold down the "-" button and tap the Power button once.

Toggling Information Shown in the Trip Statistics Row

Press and hold the "-" button to toggle between the different types of information that can be shown on the Purion screen's middle row:

  • Range Estimate (based on battery charge remaining, e-assist mode, and data from your last mile of riding)
  • E-Assist Mode (Eco, Tour, Sport, or Turbo)
  • Trip Distance
  • Odometer (total distance)

Resetting Your Trip Distance

To reset your trip distance, press and hold the "-" button and then press and hold the "+" button. An icon reading "RESET" will appear on the screen, and your trip distance will be reset to 0.

What should I do if the wrench icon appears on the Purion display?

Your e-bike is programmed to provide maintenance reminders at certain intervals. If the wrench icon appears on your Purion display, it means your bike is due for service. Take your e-bike to your Tern dealer for assistance.

What should I do if an error message appears on the Purion display?

Your e-bike's Bosch Motor System includes software that continuously monitors your bike's components. If the system detects an error, a numeric error code may appear on the Purion display. Depending on the type of error, your bike's motor system may be automatically shut off.

If an error message appears on your display, take your e-bike to your Tern dealer for help.

How do you change the Purion display's battery?

The Purion display doesn't run off of power from your e-bike's battery. Instead, it has two CR2016 coin cell batteries that need to be changed periodically. 

You'll know it's time to change the batteries when the "CHANGE DISPLAY BATTERY" indicator appears on the Purion's screen. Remove the battery cover, use a coin to remove the old batteries, and replace the batteries and battery cover.

Can you use the Purion display's micro-USB port to charge devices?

The Purion display's micro-USB port does not offer any functionality to the bike's owner, and can't be used to charge a phone or other device.

The port allows a Bosch-certified Tern dealer to monitor the status of your e-bike's Bosch Motor System and provide advanced service, such as installing software updates, changing your bike's lights to "always-on," etc. 

Bosch Purion Display Manual

For more detailed information about the Bosch Purion display, download the manual from Bosch's manuals page.