Disco 2 Nanocom 16-08

Swmbo drove the disco home the other day locked and left it on the drive. Alarm sounds, she returns checks doors sunroof excreta nothing odd. We return to use it two days later and the battery is completely flat. No radio or clock!
Battery charged no warning lights but Nanocom reports 16-08 rear right sensor output too low. Intermittent 16 times.
Can the two be linked? Could a faulty sensor cause the battery to go flat?
Do I need to replace the hub and sensor? If so any tips?

That fault code has nothing to do with battery drain it will bring on the 3 amigos eventually then you'll have to chage the hub or if no play at all in it maybe the sensor is enough

Thanks for the response.
I didn't see how it could have anything to do with battery drain thanks for the reassurance.
When I have to replace the hub I am tempted to go with the hub and sensor given the issues reported here.

Rimmer list three After market £73 OEM £152 and (gulp!) genuine £479.
Is OEM a sensible choice?

PeterSM said:

Is OEM a sensible choice?

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Yes cos at least it should have wabco sensor and the correct number of teeth on the reluctor ring, search for TAY100050G and you'll find cheaper OEM too

Stanleysteamer said:

£65 from lr-trade-parts-uk.

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The price will have changed a bit as it was late 2018, but it has behaved itself ever since!
Cheers
Stan

PeterSM said:

Swmbo drove the disco home the other day locked and left it on the drive. Alarm sounds, she returns checks doors sunroof excreta nothing odd. We return to use it two days later and the battery is completely flat. No radio or clock!
Battery charged no warning lights but Nanocom reports 16-08 rear right sensor output too low. Intermittent 16 times.
Can the two be linked? Could a faulty sensor cause the battery to go flat?
Do I need to replace the hub and sensor? If so any tips?

Click to expand...

Sorry, finger trouble, clicked before typing!

Had the flat battery problem a couple of weeks ago, was going to post here about it, but not got round to it yet.

Came to the Disco after a week, battery completely flat, ~ 5V. Charges OK at 14.5V. Had to take swmbo Peugeot to shops which started after 6 weeks idle! Anyway, charged battery which took ~ 30 hours so plenty of Ah available. Luckily battery not bu ggered as they don't like being totally discharged. On reconnection alarm went off. Shut that off with fob. Checked current draw with ignition off, 350mA for 30 minutes, then about 40mA. Too high, I have previously measured this at ~ 12mA. Checked current through fuses in engine bay by measuring voltage across each. 0.3mV across engine bay F13 = ~ 40mA, should be almost 0. This fuse is a permanent live feed to the BCU and IDM. Removed the BCU, all OK visually inside, no water stains etc. Removed IDM (what drug crazed idiot was responsible for that!) and saw a slight water stain around C0581 and C0587. Dismantled it to find evidence of quite a lot of electrical leakage around these connectors. Spent quite a while cleaning up all the mess and applying a conformal coating to the board in that area. The leakage current must have been considerable when the board was wet. Reassembled and checked, now 0V across F13 and after 30 minutes the current draw from the battery falls to ~ 15mA and no recurrence of the flat battery.

I can't help with the hub/sensor issue, I have the 3 Amigos issue, but that is the shuttle valve switch issue which I have to sort.

I have seen IDMs for sale, but all with much worse water staining than mine had.

Good luck.

PP.

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Did you mean to post here, PopPops?

Stanleysteamer said:

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Did you mean to post here, PopPops?

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Sorry, finger trouble, edited and reposted!!

OK disconnected battery earth lead and put a meter between the lead and the battery terminal. It eventually settles to 0.08A. Not sure if this is an accurate reading.
If I pull F13 I get 8mA is this too high? Do not really understand how you are measuring Voltage across a fuse?

PeterSM said:

OK disconnected battery earth lead and put a meter between the lead and the battery terminal. It eventually settles to 0.08A. Not sure if this is an accurate reading.
If I pull F13 I get 8mA is this too high? Do not really understand how you are measuring Voltage across a fuse?

Click to expand...

Yes, 0.08A is too high if all else is off, it won't flatten the battery in a few days (about 48 days for a 100Ah battery) but it probably indicates a problem elsewhere, like I had. The current consumption does fluctuate a little. sierrafery posted somewhere the background current consumption (I couldn't find it myself in RAVE) and I think it should be less than 30mA (0.03A), and I measured mine at 15mA (0.015A) recently. I think that is roughly what others have measured too.

If you get 8mA battery consumption with F13 pulled out, that is low and seems to show the current is going down this circuit, as it was for me.

To measure across the fuse, put the meter probes across the fuse while it is place. You should just see the two little metal blobs at the top at each end of the fuse, one probe on each blob. It's a bit difficult to explain and I can't give you a picture immediately. Obviously the meter need to be set to voltage, not current, when measuring across the fuse.

Good luck.

PP

Thanks Guys. I will do some more looking arround to see what I can find.

PeterSM said:

Thanks Guys. I will do some more looking arround to see what I can find.

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I forgot to mention that you need to convert the voltage reading to a current. I hope I'm not insulting your intelligence if you knew this already. For F13, you need to multiply the voltage, in mV, by 130, to get current in mA.

In the picture of the fuse below, you can see the two metal blobs I mentioned, one to the left and one to the right of the "10". Again, sorry if you realised this already.

sierrafery posted a really good way to test the fuel pump by measuring the voltage across the fuel pump fuse. He uploaded part of a table giving voltage drops against current. Below is the full file which may help with other measurements.

Good luck again.

Ah that makes sense now thanks.
Is there by any chance a table indicating what the current through the fuses should be?

PeterSM said:

Ah that makes sense now thanks.
Is there by any chance a table indicating what the current through the fuses should be?

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Sorry with any other tables. These were readings I made when tracing my IDM issue. With everything off you should get roughly (as near as dammit) to 0V across every fuse. These really low voltages are difficult to read with the average multimeter. After switching off, F11 will have about 0.5mV across it (= ~330mA) for 30 minutes. You can hear the ABS modulator ticking during this time if you put your ear against it. Not sure why it does this but it is intended behaviour. Then it will fall to 0V.

I'm sorry, I didn't measure across any of the fuses in the IDM so can't help there!

Cheers.