Battery red light, star/stop system fault

sevenhills

I think I would be getting another garages opinion. I have been getting a steering fault, possibly because of my low battery.

Goudy

The IPDM is Nissan's intelligent power distribution module.
It a ECU connected to a fuse board, full of fuses and relays and controls power to all sorts of electrical items, lights, wipers, air con fan and clutch and on and on.

Earlier Nissan IPDMs (I believe white plastic ones) had a tendency to oxidise around the relay terminals or a relay/fuse blows caused by a power spike, which might be your case.

They were replaced at some point (for black plastic, but not sure when), I am not sure if that did honestly solve the problem totally as power spikes can still happen.

Some owners have managed to identify what fuse or relay and replaced it, but you need some sort of reference of what's what, but there's no harm in checking the fuses in the board.

There is a IPDM test that cycles through all the functions, it's pretty easy and there are videos around the internet showing you how, it's basically switching the ignition on, pressing the drivers door "open/closed" switch 10 times, turning the ignition off and back on again.

Nissan forbids swapping relays and the likes, which is pretty standard from a manufacturer, they don't want repairs, they like total replacements but there might be auto electricians around that can test, identify and replace a duff relay.

TheBlacklist2013

Thanks Goudy for the indepth information as always. 

Its the black one I have got. I have tested all the fuses (under the hood, passenger and driver sides) using a multimeter, and they are fine. I have not touched the relays though, and not sure how to test these. Infact I am not sure if they are relays, because they look different. I will upload pictures later. 

I came across the IPDM self test. Apparently there are few videos for many Nissan models but not one for Qashqai, so not sure if it works on Qashqai or not. I tried the approach that was suggested in those videos, but it was not working. 

For instance, if there is a probelm with IPDM, what would be the symptoms? All the electronics on the car are working fine, and runs perfectly normal. 

TheBlacklist2013

Check engine light (amber and red) 
forward emergency braking light 
Traction light 
Battery light 
Start/stop failure 

Goudy

I'm about all out of ideas I'm afraid and just speculating.

I know modern cars will try and protect themselves when they detect a fault somewhere, hence the failure of some items and some of the lights on the dash.
They basically shut stuff down if the fault is interlinked.

If there is a break in the signal for something many items depend on, for example a speed signal, then lots of others go out that rely on that signal, not just the speedometer.

This interlinking looks like it's through the IPDM but it could be anything.

I wouldn't be happy on stumping up £1900 on any new part if this not confirmed as faulty but there are times when all the probable things are checked and good and you're only left with one option.

The dealer is probably relating the battery change to a power spike but the battery light warning (charging system warning) is a bit odd, it's not a usual warning particularly if the alternator has a healthy output.
OK, everything else might light up if there was a signal fault with something else, but why the charge light?

It might be the charging system signal isn't getting through to the IPDM or that part of the IPDM that handles that signal is faulty, which is then screwing the other systems up that also need or monitor that power/charge signal.
You'd think if the ECU detected a charge problem, then it would disable the stop start as that requires lots of power along with other systems that require a good supply of power, like the ABS pump/traction control.

It might account for the communication error, if it's using that power signal to power the communication port.

If it wasn't generating good power it would eventually run out and die, but it hasn't, it's just complaining it's not charging (and a lot of other issues that are probably related)

Again, me speculating, it would need testing out to confirm or not.

I think you've a choice now.
Find someone that understands and can test these systems, like a specialist diagnostic expert, but you could still end up with a bill for a new IPDM.
Or
Pay for a new IPDM and hope that is the problem and it fixes it.
If it doesn't then you're in for more lengthy diagnostic and probably more parts.

I would say there's a lot of dealer labour and part markup in that £1900, so if you can find a specialist, even with a few hours of diagnostic time, they still might be able to replace the IPDM (if that's needed0 for far less but confirm that it is that at fault.

Robbo66

Are you able to borrow a known good battery, I know you have had it tested but tying a different will definitely rule it out. Modern cars just don't like it when there is any sort of fluctuation in battery power, does your car have an auxiliary battery if so that may be the issue.

TheBlacklist2013

I have just replaced the battery with a brand new EFB battery. I have checked voltage on this new battery a number of times, and its always around 12.5-12.7 

Goudy

TheBlacklist2013 said:

I have just replaced the battery with a brand new EFB battery. I have checked voltage on this new battery a number of times, and its always around 12.5-12.7 

What is the voltage with the engine running?
The battery/charge light is something you don't usually see unless the system just isn't charging (or charging enough) and it should be a fairly easy one to follow on the car to test.

A good battery voltage with the engine off is around 12.5 volts, give or take a little.
A good voltage output from the alternator is around 14.4 volts (read at the battery) with the engine running.

If the battery is good and the output from the alternator is good at the battery then something isn't telling the ECU that or the ECU can't process that signal for some reason.

You could test this with a cheap OBD2 dongle and some free diagnostic software like Torque Lite (downloadable for free from your apps store).
Test the battery both running and not running (with ignition on) with a multimeter and record the findings.

If you then look at the voltage data via the diagnostic software and see if it closely reflects the voltage with your readings, both running and not running (ignition on) you took at the battery. 

If they are then it's a dead end and something else is causing the battery/charge light.

If they aren't then you are on to something.

The next step would be a bit tricky as you would need to find and study a wiring diagram.
I'd want to find the voltage signal wire to the ECU at the plug and back probe that under the same two conditions, running and not (with ignition on)
If the signal isn't getting there, something before the ECU is stopping it.
If it is then the ECU can't process the signal which possibly points to the ECU.

Something else, the ECU could be reading a default reading and throwing the charge light if it can't trust the real signal for some reason.
This reading won't likely change between the two test conditions when read with the diagnostic software.

It not unheard with modern cars for new batteries needing programming to the ECU before the car can process the voltage signal properly.
I think Nissan is one, but not sure what models and years.

castle96

Auto brake came on y'day. Frighening!! Just something I wouldhave coped with. How toturn off? Mitsi Cross Eclipse

Goudy

castle96 said:

Auto brake came on y'day. Frighening!! Just something I wouldhave coped with. How toturn off? Mitsi Cross Eclipse

What would have happened if it was something you couldn't cope with?

Have a look at the owners manual, I believe there's a switch on dash on some models, down to the right of the steering wheel.
I think Mitsubishi call it the FCM (Forward Crash Mitigation) and I think it will reset again once the ignition is turn off and back on.

Generally if you leave enough room to the car in front, the worse you usually get is a pre warning.
You might want to leave it on and consider that.