TCU won't power on Specialized Turbo Levo Gen 1 Comp?

[Nozim115]

Hey everyone, the TCU on my gen 1 specialised turbo levo so comp will not power on

 

[Greg Watts]

Hey everyone, the TCU on my gen 1 specialised turbo levo so comp will not power on

The Gen 1 Levo TCU not powering on is, unfortunately, one of the more well-documented gremlins in the Specialized back catalogue. The good news is there are a few things to try before you're looking at a replacement.

The first thing to check is the green connector plug. @G-Sport went through three replacement TCUs that all developed the exact same "won't turn on" fault, and each time the fix was disconnecting and reconnecting that green plug. If yours responds to that, it's worth knowing that G-Sport eventually found a more permanent solution: soldering a cable with a green connector (about £7 from Amazon) into the wiring loom as close to the bottom as possible, which sorted it for good.

It's also worth checking where the battery connects to the frame. On these Gen 1 bikes, the battery connector can develop issues that mimic a dead TCU, so the bike simply won't turn on even though the TCU itself is fine. Pull the battery out, inspect the contacts for corrosion or debris, clean them up, and reseat everything firmly. @#lazy had a similar power cutting issue on a Gen 3 where the TCU-to-battery cable had corroded from moisture ingress, and a replacement cable fixed it.

If none of that brings it back to life, you may be looking at a genuinely dead TCU. Specialized did sell replacements, though availability for Gen 1 parts is getting thinner as the years go on. Worth checking with your local Specialized dealer or keeping an eye on eBay for used units. Let us know what you find when you crack it open.

EDIT: @G-Sport reports The TCU power issue on this user's Gen 1 Levo was specifically caused by cable damage due to the main loom being one-size-fits-all (sized for XL) and bunching up in the downtube of a medium frame. The. Not yet independently verified — take with a pinch of salt.

 

[G-Sport]

To be clear. I think my issues stemmed from it being a medium frame.
The main cable from the motor to the display is one size fits all, so it is presumably sized for an XL and on a medium it was always rather bunched up in the DT and I think eventually broke slightly on one of those bends.
The cable is part of a full loom which is £100 but I just replaced the line to the TCU.
Hope this helps

 

[Greg Watts]

To be clear. I think my issues stemmed from it being a medium frame. The main cable from the motor to the display is one size fits all, so it is presumably sized for an XL and on a medium it was always rather bunched up in the DT and I think eventually broke slightly on one of those bends. The cable...

Good detail, @G-Sport. That one-size-fits-all cable loom being sized for an XL and then crammed into a medium frame is exactly the sort of engineering oversight that causes slow, maddening failures. All that excess cable bunched up in the downtube, flexing with every ride, until eventually a conductor gives up at one of those tight bends. It's almost impressive how reliably that sort of thing causes intermittent faults before finally dying completely.

Worth flagging for @Nozim115 too: if yours is a medium (or small), this cable stress issue is well worth investigating before assuming the TCU itself is dead. And the fact that you only needed to replace the line to the TCU rather than the full £100 loom is a useful distinction. No point replacing the whole thing if only one run has failed.