Breva 1100 Odometer Frozen

[kiwi dave]

After installing a new battery for my Breva 1100, I was surprized to see the odometer had jumped to 335,544 kM (it has done about a 1/10 of this amount) and won't increment. The spanner has also appeared on the dash. Otherwise she is running fine, but I would like to correct this small anomaly.

Tried to clear the spanner with TechnoResearch VDSTS and Centurion tools, but to no avail. When I try to clear it by doing a service reset manually via the diagnostics panel, nothing appears to change but when the ignition is switched off the neutral light (and perhaps other functions) remain on. This can only be fixed by disconnecting the battery (I pull the 30A fuses, much easier).

Does anyone have any thoughts how I can get her to behave without purchasing a replacement instrument panel?

 

[john zibell]

Dave,

It sounds like a fault with the instrument cluster. However the neutral switch signal is read by the ECU, then the information is displayed on the dash so there may be something else playing up. I'd take a close look at the injection main relay as it supplies power to the ECU. The contacts may have welded in the closed position so the key switch has no effect.

 

[kiwi dave]

Interesting point John, but I'm sure the contacts haven't welded together as the neutral light only remains on after attempting the manual service reset. It behaves normally all other times.

However, you've got me thinking that the fault may possibly be in the ECU rather than the instrument panel. My understanding is that the odometer value is stored in the panel not the ECU, but I'm now speculating that the ECU may be causing the malfunction.

I have a spare ECU for a 1200 Sport that I might substitute when I get a round tuit. Not an easy task I believe, but I've run out of other ideas.

 

[john zibell]

Dave,

Look at Carl's schematic for the 1100 Breva in the tech section (tab above).

 

[kiwi dave]

Dave,

Look at Carl's schematic for the 1100 Breva in the tech section (tab above).

I have been referring to this schematic. What in particular should I be looking for, John?

One confusing aspect of the schematic is that two connectors (black & grey) are shown for the instrument panel, whereas in reality there is only one. Also, I cannot work out the purpose of the yellow wire feed by fuse B returning to the ignition switch since it appears to effectively short circuit fuse B. But I'm yet to physically look to see if this yellow wire actually exists.

 

[Mi_ka]

After installing a new battery for my Breva 1100, I was surprized to see the odometer had jumped to 335,544 kM (it has done about a 1/10 of this amount) and won't increment.

Similar dash trouble has been reported in the forum. I believe it is corruption of the memory chip that occurs during the abrupt and indeterminate power on/off happening during battery removal due to dashboard design weak point. Most probably the dashboard processor rans wild at the power brown out that takes place and corrupts its eeprom memory if you are unlucky enough to hit the rare combination of circumstances that may have slipped through the designer's head (I have read some chip errata pdfs covering such corruption problems).

I have not read around any fix for this.
I certainly hope someone has.

Some tweaking by an experienced electronics guy may be possible if the memory chip is separate to the dash micro controller "brains" - it would certainly be not little trouble to accomplish this but is pretty doable. If no memory chip can be seen, chances are the micro controller will be "locked" and unresponsive to data reads (if the part can be identified in the first place to properly select tools for it...).

 

[john zibell]

Dave,

Based on Mi_ka's reply, I'd say your dash is toast. I don't think any research into the schematic will help.
Sorry,

 

[Mi_ka]

The problem is that any dash programming would be possible probably by the dash sub contractor only and not Piaggio...
I really hope I am wrong: A few guys run into similar trouble so maybe it is up into everybody's future when the dreaded power disconnect circumstances arise.

Kiwi Dave, did you have the ignition switch on when the battery was disconnected?

 

[kiwi dave]

Kiwi Dave, did you have the ignition switch on when the battery was disconnected?

No, I always turn the switch off before connecting or disconnecting a battery so can't blame this. The bike was without a battery for six months, I stole it temporarily for my Norge. Since I was heading for the USA for five months, I decided that it would be better to renew the battery on my return. This decision might have costed me a new instrument panel (and yes, the Norge has a new battery).

 

[Mi_ka]

Well, if it can be f@cked with the ignition off... Feck!
Such things supposedly happen when the microcontroller is in the middle of a "write" to the eeprom memory.
If then the power ramps down too fast (we are talking about milliseconds here) the write can be easily corrupted. Nothing more that some bigger capacitor along with a low barrier voltage diode cannot take care in the power feed, (that is why I am very interested in Dashboard PCB closeup pictures to do some reverse engineering, if possible).
Also, when power is reconnected, it ramps up. If the ramp up is not up to the specified duration and no reset holding control has been employed the "brains" can ran erroneously the dashboard application program in a chaotic manner and start executing the eeprom write when not supposed too and mess things up.

When the battery is dis/connected there is a momentary power on/off situation (milliseconds remember!) that can be made worse if we move the cables slowly to/from the battery terminal scratching it along the terminal (this also happens every time a mechanical switch is pressed and is called contact "bouncing").
By any chance do you remember if you made the connection in a more than a swift and decisive move?
Not an excuse for the designer, though!
What must have been messed up is just the mileage I hope. If I am not mistaking as I 've read recently, the dashboard holds the barometric pressure sensor and passes its readings digitally to the ECU. In such dashboard devices' memory there are usually stored other data regarding the application like miles/kilometers, calibration data, serial # etc and all these. So far I have not read of dashboard corruption leading to other problems (except a reference a the bottom of this post here: https://www.guzzitech.com/forum/163/7506.html?start=10#p56947) but I would do a thorough check-drive to see if anything works differently. Other guys reporting such trouble have never said anything more than mileage corruption, hopefully.

 

[kiwi dave]

When the battery is dis/connected there is a momentary power on/off situation (milliseconds remember!) that can be made worse if we move the cables slowly to/from the battery terminal scratching it along the terminal (this also happens every time a mechanical switch is pressed and is called contact "bouncing").
By any chance do you remember if you made the connection in a more than a swift and decisive move?

I always try to get the last (negative) connector on smoothly, and it's easier on the Breva compared with some other models that have three cables to each battery terminal. Methinks I'll be pulling the 30A fuses before connecting or disconnecting a battery in the future. Fuses can be removed and inserted much easier.

 

[Jim.x.harding]

I have a Griso mileage that jumped from 8300 to 939,000 when the battery was changed.
Looking through thsi post, I assume there is no know fix and it's new instrument panel time? Ugh. $1200 from what I see, which isn't ideal.

 

[Mi_ka]

Did the shop involved had the main switch on when you changed the battery?

If you can find a guy like me (micro controller enthusiast - freelancer or so) close to you (I am located in Greece,Europe) , there is a good chance he could locate some maybe I2C memory chip, take a Hex dump fromits contents, tweak the proper bytes and reprogram it and be ready to go for much - much less.