Specialized Turbo Levo assist level 3 not switching on — anyone else?

Turbo level 3 won't switch on.

@Greg Watts

Welcome to the forum. "Turbo Level 3 won't switch on" is a phrase that could mean two or three different things, so let me cover the most likely interpretation: a Specialized Turbo Levo Gen 3 that refuses to power up at the TCU button.

This is a known gremlin and you're in good company. The pattern usually goes like this: press the power button, nothing happens, or you get five or six attempts before it finally wakes up. Sometimes it switches off cleanly but won't come back on.

The usual suspects, in order of likelihood:

1. The Rosenberger plug at the battery. Open the hatch, disconnect the main power cable from the battery, give the contacts a look (corrosion, debris, bent pins), and reconnect firmly. Riders here consistently find this resurrects the bike, at least temporarily. If reconnecting the plug makes it switch on every time, you've found your culprit. The fix is often a new power cable (Specialized charge around £130 for one, which is its own kind of pain).

2. The TCU itself. @G-Sport went through three TCU replacements that all failed the same way — needing the green plug disconnected and reconnected to wake the bike. If the cable swap doesn't fix it, the TCU is the next stop.

3. TCU-to-motor cable. The other failure point. Dealer told one rider to replace the TCU-to-motor cable as well as the power cable under warranty.

4. Internal coin cell. The TCU has a small battery that enables the on/off switch. If it's dying, the button stops responding even though the main battery is fine.

Quick diagnostic: does pressing the button on the battery itself wake the bike up, even when the TCU button doesn't? If yes, your problem is between the battery and the TCU (cable or TCU). If neither button works, the main battery may have gone into deep sleep — try putting it on charge for a few minutes and trying again.

If it's under warranty, push the dealer hard. This is a documented issue and they know it.

Tell me the model year and whether you get any LED flashes when you press the button, and I can narrow it down further.