2021 Turbo Levo SL carbon power goes off

[rede]

Last ride. Power suddenly turned off, but returned when pressing button. A little later, same thing, and at one point, happened every few minutes. Usually had to turn it back on myself, but sometimes came back on itself. Turned around at 9 miles, and later, maybe at 12 miles, returned to normal. One more incident later but finished at 18 miles, working normally. Screen had showed blue and red bars, indicating battery/motor error. LBS says needs a battery stabilization kit, which secures the battery and its connections. Hope that's the answer. The test is a longer ride, and the chance of getting marooned.
Any one have similar problems? If so, what was the diagnosis and fix?

 

[Base]

Sounds indeed as an "intermittent contact issue". Did they check al connections in the cable harness? (Unclipping, cleaning and firmly closing). A very common issue on e-bikes which do have a hard life on mtb trails

 

[rede]

The bike is at the shop now. They said they have to remove the battery, which involves dropping the motor, and they'll be able to check the connections. Just thinking, I had the range extender battery in place. Even if the main battery connections were failing, the RE battery should have kept the power on. Another mystery? I see that the bike can be ridden with the RE battery only, with main battery removed, so that's a separate connection.

 

[Base]

sure, it sounds like a faulty connection on a connector. Could be the one on the DU or going to the HMI. I would not suspect the primary battery connection, it usually is the one to the HMI in my experience.

 

[rede]

Sorry, but what is a DU or HMI. If you mean screen, my 2021 SL only has a "screen" (TCU) showing the battery charge level in blue/green "bars", plus the boost level "circle", not like the newer versions.

 

[Base]

Indeed, sorry. DU DriveUnit, HMI is Human Machine Interface (tcu/tcd/remote etc). Your symptoms are usually caused by a faulty connection at the "display" or at the "motor"

 

[Stefan Mikes]

Last ride. Power suddenly turned off, but returned when pressing button. A little later, same thing, and at one point, happened every few minutes. Usually had to turn it back on myself, but sometimes came back on itself. Turned around at 9 miles, and later, maybe at 12 miles, returned to normal. One more incident later but finished at 18 miles, working normally. Screen had showed blue and red bars, indicating battery/motor error. LBS says needs a battery stabilization kit, which secures the battery and its connections. Hope that's the answer. The test is a longer ride, and the chance of getting marooned.
Any one have similar problems? If so, what was the diagnosis and fix?

When did you last replace the CR1220 battery inside the TCU?

 

[rede]

Just a month ago. Had the red line signal. A really stupid design, like they purposely made it almost impossible to change. From looking at various forums, it seems that battery is just for the display and is not in the control "circuit". Or am I wrong?

 

[Stefan Mikes]

From looking at various forums, it seems that battery is just for the display and is not in the control "circuit". Or am I wrong?

In my opinion the TCU is the very control unit of SL e-bikes.
However, as you had changed the coin battery, it cannot be the reason for your SL issues. Did you speak with a Specialized dealer about the diagnosis @rede?

 

[Base]

The TCU is basicli the HMI, it is the interface between the rider and the brainpower of the bike. The man PCB is in the DriveUnit. The on/off circuit needs power, with power it can send a signal to the pcb which wil start the boot of the intire system. see it like on you pc/laptop. All these systems use a "boorloader" mostly in the form of a BIOS. That part of the system starts when you feed power to it, than it witll trigger all the various systems to startup (getting them power) and than start the boot strap with starting the MBR with UEFI/Grub or something similar. The same thing happens on an e-bike.

in most cases the system remains actief, sleep mode, like the standby of for instance your TV. depending on the system this can stay like that for a longer period (bms in the battery would usually going to stepdown in months not in weeks). So when the batteries bms is still in an" active" state it can power the primairy circuits of the system so you could start it up wih the start/stop button on the hmi. If the battery has been shutdown for a longer period than the system goes to deeplseep and than hybernation, in those states you would need an external powersource to wake up the systems, the TCU has the CR1620 in it for this purpose. If that coincell is emtpy you can wake up the batteries bms with the charger, that wil than powerup the entire system. For a Bosch bike for example you can start the system with a "live" battery which you switch on with a pushbutton, same goes for Shimano (first system alays needed to be started via the battery). And with later version of these e-kits most hmi's/displays have a rechargable circuit inside. You ususally can charge them via usb.

so in this case the symptoms are more of that of a crappy connection, intermittetn contact. Like in the old days when you put the jack plug in your walkman and had to turn it a few times before the jitter was gone from the music output. The system looses one of the main components (contact between the DriveUinits pcb and the TCU hmi) and than you are able to switch it back on. First suspect is one of the cable connectors. if these are clean and sprayed with contact spray and the failure re-occurs than either the central cable harnes is damaged or the cable connector itself. Most like it would be easier to test thsi by placing and known ok tcu and take the same test circuit to ride the bike where it previously failed. If the failure is gone the tcu needs to be replaced, if the symptons re-occur than the cable harnes should be swapped. If that doesn't help, the battery should be checked with a diagnostic tool (or swapped if it is warranty) and the driveunit could undergo some tests.

that would be my route as a mechanic.

 

[Stefan Mikes]

So you Base work for Specialized and know how the Specialized SL system works.

 

[Base]

my current employer is not the guys in Arnhem, but I've worked with a lot of mayor e-bike systems both as a workshop chef and working for different brands in this branche. In the field of 3rd line e-systems trouble shooter, development, compliance and currently in the quality field. I've been working on e-bikes since the mid '90's when the Sparta Pharos was the first real commercially available e-bikes in the benelux.

Even today people from the bussiness ring me if they have a sympton they cannot unravel for my help in solving these symptins at a dealer or consumer bike. And I am involved in the development of new products besides training the staff and dealer network. As a matter of fact I ran some dealer tranings in the early days that Bosch came to market te get them Bosch certified.

You might want to ask my co-workers, but I think I now a few things on e-systems.

 

[Stefan Mikes]

You see, Base, Specialized SL system is not Bosch.

Here are a couple of sentences of the TCU of the SL system from support.specialized.com

Turbo Connect Unit:

• Master component in CAN system ("brain" of e-bike system)
• Key funtions:
  • User interface
  • Control e-bike system
  • Manage CAN communication
  • Connectivity module for ecosystem devices and applications

In the Bosch E-Bike system, the display is just a display. In the Specialized SL system, the TCU is the control unit.

Useful reading

2021 Specialized SL e-bikes do not have a display; you use ANT+ to connect a display (I use a Wahoo for a display).

 

[Stefan Mikes]

Additional question @rede (see also post #9): Did you try to connect to your SL with BLEvo? The Battery Monitor could give you some more insight.

Here is what Specialized writes about the issues with the SL TCU Gen 1:

Simple check-steps in case bike does not power on:

1. Connect a powered USB-C cable to the display* - if the display starts up, you can assume that the display itself works and you would leave the USB cable connected to charge up the display battery for a few minutes; after that, check if the bike powers on through the remote
2. Connect a Range Extender Battery - if the bike starts with an RE only, you know that either the internal battery has an issue or that the connection from the internal battery to the main harness is not okay
3. Connect a powered charger to the charge port and observe the charger diode
   1. Green:
      • Battery cannot be charged, reason could be a problem with the main harness or connector at the main battery - this would also explain that the bike does not power on (w/o RE connected)
      • Battery fully charged
   2. Permanent red:
      • Charging
      • Leave the charger connected for a few minutes, disconnect it, and try starting the bike via the display button
   3. Flashing red:
      • Problem with the internal battery or charging attempted outside the allowed temperature range
      • Disconnect the charger and only re-attempt charging if charging happened outside the allowed temperature spectrum

*) They mean TCU; you should remove the TCU from the frame first, of course.

I still recommend seeing a Specialized dealer for a diagnosis.

 

[Base]

You see, Base, Specialized SL system is not Bosch.

100% correct and inline with what I wrote, exacrt same features as what the HMI of other systems do and how these systems work.

And yes, I have experience with the Turbo systems from within our and other bikeshops. I cannot deny that I could have the PC interface for these type of products.

Like OP says, the bike is at the dealer and they are checking te connecion on the battery.

If the battery connectionis fixed and there is still a sympton as discribed than the next step (and what they allready should have done) is checking the cableharness connectors. Also in the light that the OP had the RE connected.

 

[Stefan Mikes]

The main difference between Bosch E-Bikes and Specialized is Specialized does not depend on the e-bike system manufacturer. That is why we ask Specialized dealers for help in harder cases.
FYI, the majority of issues related to the SL system has been either a spent coin battery or a discharged internal battery for newer TCUs.
The case of Rede is on a different level, requiring a professional help.

 

[Base]

you are talking about what in the industry is called system integrators. For Bosch the is just one flavour, they are the complete integrator. For the other brands that is a bit different, the OEM has the choice to either pick off the shelf solutions with a small portion of mods (so it works with the bike design) or design their system based on a DriveUnit coupled with their own flavor of batteries and HMI's. Good example would be Giant with their iterations of Yamaha, Shimano and Mahle systems. Exactly the game where Spesh is at. The only real "closed" system is Bosch, the other brands do have options.

 

[rede]

As previously stated the bike is in the shop for repair. They are backed up, and I have to wait a few days. The tech said my case of the power shutting off intermittently is a "text book case" of the battery shaking around and losing connection. This is why they will be installing a battery stabilization kit that has some kind of extra brackets to hold the battery securely and maintain connection. Am told they will be doing this under warranty, surprisingly, so it seems this is a known and important issue for Specialized.
As mentioned, the battery shutoff repeatedly happened, and then towards the end of the ride, the bike performed normally. The TCU screen showed the blue and green charge bars and the boost circle. When the power went off repeatedly, the Mission Control screen (iPhone) went off, and then returned when power went back on. The entire ride was fully recorded, and the ride data seems complete and normal. It shows that both batteries used 36%. Also, as stated, each time the power came back on either automatically, or by me pressing the button, it would be in turbo level. And, again, I had the RE battery installed, so why didn't it just run normally, as the bike is said to be able to run with the main battery removed.
I'm concerned that the battery stabilization kit may not be the answer.

 

[Stefan Mikes]

I think @rede the system would have worked on the RE if the main battery were totally disconnected. I can imagine what happens when the main battery is intermittently on and off.
In case the main battery is present and there is the RE connected, the SL system does not use the Range Extender only even if you are in the 'discharge the extender battery first' mode.