Modern Vespa

I brought a used Vespa.
However, both ABS and asr are always on.

It didn't work, so I left it to the dealer
The scanner gave an error of u1601 unknown

I found a wiring disconnection and reconnected it

Abs and asr blinked and functioned normally

But after I put it back together, I started the engine, and it didn't work again, and both ABS and asr are on again

I adjusted both the battery change and the tire pressure
Still doesn't work on my Vespa......

It works very well if you drive it when it's disassembled
But after assembling, it's always on again and doesn't work.

Help me. What else should I check?

I also tried resetting the asr

Also, if you attempt to connect to ABS START from the TEXA scanner,
There is no communication.

which connection?

Error Code U1601:

Code E4: U0002
Code E3: U1601
Description: CAN line"Mute Node" - Mute Node
Detail (Symptom): Mute Node
Warning light status: F
MIL light status: N
Recovery: Cruise Control deactivated Traction Control deactivated
Action to do: 1) Reconnect/repair connectors 2) Reconnect/repair wiring harness 3) Replace 7SM ECU

One of the broken wires connected to the ABS module was reconnected.

Thank you for your answer! But I didn't understand.
What should I do?

First off all: Please note, that this from a workshop manual for Aprilia bikes, but should comparable for Vespa.

According to error code it seems that there is no communication with ECU possible.

See "Action to do"!

If it is no problem with connectors and/or wiring, the ECU itself could have a problem…

Good luck!

Has anyone jailbroken ABS ASR systems yet to manually override to off?

I'd rather have ABS than not but many say (including my Haynes manual) a good, attentive rider stops faster on a non-ABS bike.

As far as I know, converting to an ABS-less ECU also requires rebuilding hand pumps, brake lines, and calipers. But honestly, I'm technically out there now... Let's hope that there are still knowledgeable people around here

This:

By staring at the wiring diagrams I understand the following:

The ABS unit gets the individual front/wheel speeds from the tone/speed wheel sensors. The ABS does not require the ECU to do it's job.

The Speedo gets it speed from the ABS - not the sensors - via a dedicated wire direct from the ABS (not the CAN bus).

The ECU gets both wheel speeds from the ABS (via CAN bus*) and uses that data to implement ASR and the speed limiter.


So fully disconnecting the ABS would screw up the Speedo and ASR and speed limiter but I guess it could be kept electrically connected and just the brake lines disconnected from it and then the Speedo and ASR would still work.

To make ASR disabled without having to turn it off each time you start the scoot (which is an easy habit to form - I do it most of the time) would obviously require modifying the ecu. theoretically possible but haven't heard of anyone doing it. the ecu has been 'jailbroken' for older gts, but I've only heard of a couple of guys messing with the hpe ecus - not yet common practice.

I've never heard of jailbraking the ABS - not something I'd recommend anyway.



* or maybe k-line on older GTS

Most probably either there is more broken wires or unplugged connectors OR the tone/speed wheel sensors are malfunctioning. eg the tone wheeld could be bent out of alignment.

And check the fuse for the ABS, read the manual to find out which one.

Thank you for your answer. I didn't break out.
ABS and ASR are not working, so during maintenance
One of the connectors is disconnected and has been reconnected.

Before assembling, test runs show normal operation and
The speedometer also worked. However, it does not work again after assembling it to finish the repair. I don't know that.

All fuses in the fuse box are normal.
I checked it out.

have you tried disassembling again to see if the same connector has disconnected again?

One of the wires connected to the connector was disconnected, so I reconnected the wires and disassembled and assembled them.

Check the abs sensor, there is one in the rear tire and another at the front tire. Maybe one of them is rusty or defective.

I checked that both sensors are working normally.