Does the pointy ECU have it's own battery?

[Baph]

As the title. :)

Some of you may know that I've been having some electrickery gremlins on my K6 (if you keep up with events in this section you'll know anyway).

This morning when I turned the key, the LCD display showed dashed lines everywhere (pointy owners will know this isn't normal behaviour). It caught my eye & I thought "Aha! That was a reset if ever I've seen one!" So I turned the ignition off, then back on to see if I could replicate it. Nope.

I also noticed that the clock in the LCD display has randomly changed itself (I noticed this the other day too), which applying knowledge from PC's, would point to some form of CMOS battery.

So, does the pointy ECU have a battery inside it? If it does, can this be replaced without getting a new ECU (expensive for a brand new one, I've just checked alpha-sports :shock:)?

I can't see it being a constant 12v feed from the battery to be honest (though more than happy to be wrong, esp if it'll save me the best part of £600!!).

This fault is also independent of any alternator/reg rec issues I may have (but haven't had chance to test yet), because the engine wasn't on, just the ignition.

I didn't see any gremlins for the journey to work either. So maybe the ECU was just having a brain fart the last few days, but I think that's just me hoping TBH.

Thanks :)

[flymo]

I dont think it does Baph, when I was wiring up my race loom I had the clocks and ECU on and off many times. From memory I gave up setting the clock in the end until I had finished.

There is probably a permanent live from the main battery.

[flymo]

JUst checked on the wiring diagram and it seems there is a permanent 12v through a Red/White wire to the ECU via fuse number 3.

You probably have a dodgy connector or corroded earth connection somewhere.

[Baph]

There is probably a permanent live from the main battery.

Cool. :) That could probably save me some money then. :)

Another thought I had, are the clock (time) functions done by the ECU itself, or within the dash setup?

IIRC, the dash has a permanent live from the battery, so perhaps that's where things are going screwy. This would also tie in with my other gremlins, namely random lights (oil/FI and fuel) coming on, and again would point to either the headstock connector or the rec/rec.

EDIT: Muchos-grassios for the 2nd post flymo. :)

[flymo]

Another thought I had, are the clock (time) functions done by the ECU itself, or within the dash setup?

IIRC, the dash has a permanent live from the battery, so perhaps that's where things are going screwy.

I think you're right, the clock is built into the dash unit, its not data passed from the ECU. Edit...Does the mileage follow the clock unit rather than the ECU? I think it does which implies that data is not passed between the two other than basic pulses for revs etc.

The same Red/White live feed runs to the instrument unit also.

The obvious ones I would check are;

1. The instrument panel connector (directly underneath the unit)
2. There are three connectors just behind the headstock in the engine bay, a little tricky to reach without taking the tank/airbox off but you might just be able to get to them with the radiator pulled forward on the left side.
3. main wiring loom earth points, I think there is one in the engine bay, right hand side near the right hand coil.
4. battery connections, make sure they are clean and tight. I had one vibrate loose on mine.

[Baph]

Does the mileage follow the clock unit rather than the ECU?

Yup, the mileage is dependent on the clocks, not the ECU/engine.

I personally was going to start with 4, 2, 3, 1 from your list, then check the rec/rec (first check the battery voltage under load whilst checking 4). :)

Thanks again. :)

[Dangerous Dave]

It has no self contained battery.

[Baph]

It has no self contained battery.

Cool, at least I know it's likely not to be the ECU.

Now, SoulKiss was looking at clocks, the LCD unit is a bit of a "black box" and that's what I need to look at next really...

Cheers DD & flymo. :)

[thefallenangel]

if it's what looks like a reset, i'd go along the wiring diagram and trace that 12v supply and go from there. Power loss somewhere has caused a reset.