Aventon Pace 500 – Installing Throttle on Demand Controller Upgrade

I was excited to see Aventon’s Throttle on Demand Controller and new BC 280 Display. The Pace 500 has been awesome for the past 3 years, but its controller and original display had their flaws.

Aventon currently provides no Installation information, and instead suggests hiring a bike repair shop:


We highly recommend having the retrofit kit installed by an authorized Aventon dealer or a mobile bike repair and assembly service such as Velofix or Velotooler.

If you are the original owner of your Aventon ebike and are still within the 1-year warranty, it is a requirement to get the retrofit kit installed and verified by one of the options stated above in order to maintain the existing 1-year warranty.

  • Additionally, getting the retrofit kit installed by one of the options stated above will qualify your ebike for a 90-day warranty extension after the installation regardless of your Aventon ebike’s current warranty status.
  • In order to qualify for the 90-day warranty extension, you must provide proper documentation proving it was installed professionally and must be the original owner of the ebike.
  • If there isn’t a nearby Aventon dealer or mobile bike service near you, please contact customer service before installing the retrofit kit to your ebike: Contact Support

Installing the Controller

In case anyone wishes to waive their warranty rights as I did, here’s how the installation process went. Time spent: about 20 minutes.

  1. Remove the battery, then unscrew the two screws from the lower battery tray:The old controller is packed in the bottom of the tube.
  2. Disconnect the 48V supply wires (black and red wires with blue crimps).
  3. The controller has three wires: display wire, motor wire, and brake signal wires. Carefully disconnect the two smaller wires. The waterproof connectors can be disconnected by hand (pull HARD).
  4. Disconnect the motor controller wire from the motor:
  5. The motor wire is held in place with a plastic retaining clip near the tire. You can release it with a flathead screwdriver. There were a couple zipties on my wire bundles, which snapped as I began working. You may need to clip these as well.
  6. With the motor controller wire free, pull the old controller out of the frame. I removed the rubber grommet on the bottom of the frame to make the process easier. Not sure if this was necessary–it was a pain to push back into place.
  7. Install the new motor controller: Start by routing the motor controller wire back through the rubber grommet, but leave the motor disconnected until all other wires are connected, as you may need to reposition the controller and other wires while reconnecting the brake, display, and 48V leads. Connect each wire firmly.Important: Observe the orientation arrows on the motor/brake/display leads! Also be careful to position wires so that they are not crushed or damaged by the controller. It’s a tight fit:
  8. Reconnect the motor and reattach the plastic retaining clip to secure the wire:
  9. Reattach the battery tray with original screws. Done!

Installing the BC 280 Display

Aventon provides a PDF guide for this part. It’s straightforward: unscrew and unplug the old display, then reconnect the new model.

First Impressions

So glad I upgraded, despite the expense! The Pace 500 feels much smoother, and I can now unlearn three years of habits to avoid throwing myself from the bike at standstills. 😀

It’s All Firmware…

Here’s the original controller:

And here’s the new Throttle on Demand controller. Notice both are marked Tongsheng Powertrain KZQW22A3-JH-TDGW22700C:

The controller has an unused 4-pin header. Could this header be used by Tongsheng for programming? I could be wrong, but if loading firmware is possible using a generic serial programmer, I would have preferred this over swapping perfectly good hardware. Most likely the necessary tools and knowledge are outside the area of expertise of the average bike repair shop.

Edit: Reading/writing firmware is likely possible using an ST-Link programmer. I have one of these somewhere, and will try to dump firmware from both controllers soon…

11 Replies to “Aventon Pace 500 – Installing Throttle on Demand Controller Upgrade

  1. Did you figure out how to update the old controller firmware? I would love to have mine updated. Would you consider updating the old controller and swapping it with my old controller? I don’t care about a new display. I just want throttle on demand and a gentle start on pedal assist 1.

    Rita Gregory. [email protected]

  2. I have 2 Pace 500 bikes that were rode only once, then were in a mobile home in Fort Myers during hurricane Ian. They were submerged in 6ft of salt water surge. I am trying to make them roadworthy again. A new rear wheel/hub and a good battery fixed one, but the other one gives me a error code of 30, communications error. All wiring looks good, I suspect maybe the controller or display have the problem. Would I be risking ruining my good controller and/or display if I swapped them out to diagnose the problem?

  3. Does anyone have a KZQW22A3-JH-TDGW22700C controller for sale? Does not matter if it is TOD or Throttle After Pedal, just as long as it is a KZQW22A3.

          1. Hey Jseaber,

            Do you still have the controller? im looking for a replacement for my level.1

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