By the way, in relation to the original post and query about the ECU serious error warning, although this persisted while working on the bike, once the machine was back together and on the road, the warning disappeared. The logged 56 error also cleared. That’s a relief.
The serious error display reappeared when I had the neutral sensor wire disconnected. After it was reconnected and the bike rolling again, the warning went away. Touchy character, that ECU.
How come the ECU was aware that the neutral sensor wire was disconnected? If the sensor is just a switch that is either on or off, why does disconnecting the wire present a state that is different to the operation of the switch itself?
Or…
could it be that the ECU didn’t like the other thing that I did, which was to connect a small light bulb to the neutral sensor terminal in order to keep an eye on how the sensor/switch was working mechanically (removing the wiring loom factor to be sure that it is the sensor itself that is erratic). The bulb of course had to be fed with 12V, but I didn’t see that making a live bulb circuit there, through the gearbox, would be a problem. However I removed the bulb after the ECU warning – just in case – (so I haven’t been able to verify the neutral sensor operation over time, independent of the normal wiring to/through the ECU). belfastguzzi2012-08-02 09:28:46
Progress hmm, a mate of mine has the newer Passat he blew a rear brake light went to the local Halfords bought one he thought was correct popped it in and got a stuttering engine on cruse control, warning lights on the dash. he popped into Halfords, …it was “the wrong bulb!” correct bulb put in all the errors dissapeared ???
A Valeo will pull about 50 Amps, a Bosch about 40
If you calculate the resistance of the two coils in parallel it works out ~ 0.2 Ohms
Say for argument sake you had a total resistance of 0.2 Ohms through all the wiring, ignition switch, fuse, relay the instant current would be 12 / (0.2 + 0.2) = 30 Amps
By cutting out half the wiring it’s reasonable to think you could at least cut the resistance in half e.g. 0.1
So now the current to pull in the starter is 12 / (0.1 + 0.2) = 40 Amps
BTW I think I am being realy generious in saying the total wiring is only 0.2 Ohms, I have seen the ignition switch alone many times that. >
Actually not quite, the solenoid has reactive inductance, because it’s a coil, so the current increases from zero, therefore I imagine at some point it’s enough to pull it back. At that point it’s switched out leaving just the holding winding. I doubt therefore it’s a full 40 Amps, hasn’t had time to get that high.
Bu-ut, if for some reason it can’t, e.g. the pinion’s stuck and won’t slide, then it’ll blow the 16A fuse. As the DC resistance of the coil is so low that’s probably highly advisable!
I honestly don’t think Guzzi understand there are two coils in the starter solenoid otherwise they might show it in their schematics. >
Eau contrare there’s a detailed description in my MG workshop manual.
If you mean on wiring diagram, probably thought irrelevant (too much info)
GJ, as far as I know the only canbus wiring on a Guzzi is the connection between the dash and the ECU.
BFG, the ECU does a global check on all sensors when you turn the ignition on. If you have disconnected the wiring to the neutral switch, it will find this and log an error.
Mike, a low voltage supply to the solenoid coils will also, surprisingly, cause the fuse to blow, as there is not enough power to pull the solenoid in. This has been checked by several across the pond and results published.
On mine, I also found the solenoid plunger was covered in dried sticky grease. Removed this and oiled instead, no further problems.Brian UK2012-08-02 16:26:27
“BFG, the ECU does a global check on all sensors when you turn the ignition on. If you have disconnected the wiring to the neutral switch, it will find this and log an error.”
Brian, I can buy that, but my puzzle is, why does The ECU see a disconnected sensor differently to a sensor that is in the off position? The ECU does not complain with a warning if the bike is started up when the gearbox sensor is not registering neutral.
Is it because as GJ says, these sensor devices are no longer just on/off switches: there is some other trickery involved?
There may always be some residual current going through the switches, I found when I fitted heated grips to my Guzzi, even when everything was off not calling for power there was a small current present when the ignition was turned on. This increased when I pressed the heater switch to position 1 etc. Try connecting an avo meter and see what happens when you switch on.