The Vala runs the Bosch CX Gen 5 (Smart System), so the update is going via the eBike Flow app. Failed updates on Smart System are common and almost always recoverable — here's the order I'd work through.
1. Basics first
• Battery above 30% (ideally plug the charger in during the update — a dropout mid-flash is the usual culprit).
• Phone within a metre of the bike, screen on, app in foreground the whole time, bike awake (give the button a prod if it sleeps).
• Close every other Bluetooth app on the phone (Garmin Connect especially —
@Rob Rides EMTB tracked a Gen 3 Levo update failure to exactly that, and the same BLE contention bites Bosch).
• Toggle phone Bluetooth off/on, force-close eBike Flow, reopen.
2. If it still fails
@slavio had the same symptom on a Bosch Smart System bike — phone update appeared to push, then the system controller LED blinked for 1–2 minutes and threw "Update failed" at the actual bike-flash stage. Bike still rode fine, but the phone simply couldn't complete it. Fix was a dealer with the Bosch diagnostic cable finishing the job in two minutes.
3. Before you book the dealer trip, try:
• Remove the battery, wait 30 seconds, refit, retry.
• Uninstall and reinstall eBike Flow, sign back in, re-pair the bike.
• Try a different phone if you have one to hand — Android vs iOS sometimes behaves differently on the same bike (Specialized support actually recommends this trick for Mission Control; it's worth a go on Flow too).
• Check whether the failure message mentions
Drive Unit,
Battery,
Display or
Connectivity Module — Flow updates each separately and one stubborn component is often the whole story. If it's always the same one failing, that's gold for the dealer.
Worth knowing
@Plummet noted that on the latest Vala firmware, range is unchanged
unless you actually run the 100Nm boost mode — so don't avoid the update on range grounds; just get it landed.
If none of the above gets you through, it's any authorised Bosch eBike centre job with the Bosch diagnostic tool — not a warranty issue, just a 10-minute bench flash. There may be a small fee involved.
What's the exact wording of the failure message, and which stage does it die at?
EDIT: Corrected the claim that you need a Santa Cruz dealer — any authorised Bosch eBike centre can do the diagnostic flash, not just a brand-specific dealer. Thanks
@Paulquattro for the heads up.