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NotAnotherLandRover

Member
Apologies, this is a long one, bear with…

I’ve got ADHD and this means my brain sometimes neglects to do the most basic of things…. Like turning the ignition off and taking the keys out of the car overnight ‍♀️ This inevitably caused a flat battery and despite a hard reset and battery recharge it won’t start.

We’ve got warning lights and messages all over the place.

Today we spent some time going over a few things.

It’s deffo not the battery, it may have been the low voltage that’s caused the problem, but that’s not the problem now.


When we’ve plugged into the diagnostics scanner we’re not getting any communication from the engine ECU at all. All the other modules on the car communicate fine but are obviously reporting codes that there’s no communication with the engine ECU as you would expect.


We’ve checked the voltage to the pins at the ECU and the earths are there, the supply battery voltage is fine, the feed from the ignition switch to the ECU is fine but the ECU is not supplying the earth to the engine control relay. Which is obviously the problem…


But is this caused by the ECU failing or is it that the immobiliser is stopping the ECU? When we key on the immobiliser light continues to flash. It may be flashing because the ECU isn’t switching the relay.


Even if we bridge the relay - we still get no communication from the engine ECU. Perhaps pointing back to the ECU again.


Does anyone know how the immobiliser operates and where is it? Is it in the ECU, the instrument cluster or the BCM?


Side note, also noticed the water temperature gauge is off the scale (guessing this is because there’s no communication) and the other thing that’s strange is that with the ignition on you can move the gear selector freely without pressing the brake pedal.


I’ll take any wisdom right now thank you x
 
Nowhere in this does it say what the battery voltage actually is , only that you consider it to be "fine".
You've shagged the battery and its all started from there. Give us a clue, what's the voltage?
<12.7v it's still ferked.

You really need Gary Stuart on the case @gstuart .
 
Last edited:
DanClarke said:
Nowhere in this does it say what the battery voltage actually is , only that you consider it to be "fine".
You've shagged the battery and its all started from there. Give us a clue, what's the voltage?
<12.7v it's still ferked.

You really need Gary Stuart on the case @gstuart .
Click to expand...


Doh. Forgot that detail. It’s 12.9v

thank you xx
 
Hi

what signal feed voltage at the ecm did u get plse and what pin as I’m not sure ur testing the correct one, what ecm earth points did u also check as that will then let us know what ur testing

have u also checked all ur fuses , 12.9 Vdc with the engine off sounds high, unless of course that’s just after being disconnected from a battery charger

indeed am very familiar with the immobiliser system on these and if the lights are still flashing the starter motor won’t have any power as the immobiliser with stop it as per its job

lastly what scanner are u using plse, also what year ur d3 is and what engine

Hope that helps as we can try and get some info of what’s going on, lastly we’re there any errors before this plse ,thks
 
Last edited:
NotAnotherLandRover said:
....despite a hard reset and battery recharge it won’t start.
Click to expand...
Did you do the hard reset after the charged battery was fitted or before that? if yes do a hard reset after the system got good voltage... also the voltage reading is relevant only with ignition on, what's on the battery disconected is completely irrelevant so if you get below 12V with ignition on get a new battery, it's important also to disconnect the negative lead first and reconnect last when you change the battery, doing it the other way around can mix up the management... if the vehicle has BMS it must be reset with tester and that's valid if the battery was once flat and removed, read the attachment
 

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gstuart said:
Hi

what signal feed voltage at the ecm did u get plse and what pin as I’m not sure ur testing the correct one, what ecm earth points did u also check as that will then let us know what ur testing

have u also checked all ur fuses , 12.9 Vdc with the engine off sounds high, unless of course that’s just after being disconnected from a battery charger

indeed am very familiar with the immobiliser system on these and if the lights are still flashing the starter motor won’t have any power as the immobiliser with stop it as per its job

lastly what scanner are u using plse, also what year ur d3 is and what engine

Hope that helps as we can try and get some info of what’s going on, lastly we’re there any errors before this plse ,thks
Click to expand...

Thank you,

Tested the following pin numbers
CK4 - Battery Feed - 11.6v
CK3 - Ignition On Feed - 11.6v
CF3 - Ignition Feed (Cranking) - 11.6v
CE3 - Transmission Control Module - 11.6v
CM1 / CM2 / CM3 / CM4 - ECM Earths - Good Earths
CJ3 - Switched Earth Engine Control Relay - 11.6v ignition off or on - which obviously is why it's not switching the relay
CL1 / CL2 / CL3 - Engine Control Relay - 0 unless we bridge the relay ourselves at which point we were getting 11.6v

Yes 12.9v on the battery was when it was taken off of charge.

Checked all the fuses last night, and all seem fine.

The scanner is a Snap On Verus Pro - all up to date

and the obvious information I left out which is the car - 2004 Discovery 3 - TDV6 2.7 - ADHD brain letting me down again there!

Thank you, Hannah xx
 
12.9 is ok if that was shortly after being charged.
11.6 sounds too low with the ignition on
If a battery drops much below 11.0 while cranking the engine then it's goosed. What does it read with the headlights on?
 
kermit_rr said:
12.9 is ok if that was shortly after being charged.
11.6 sounds too low with the ignition on
If a battery drops much below 11.0 while cranking the engine then it's goosed. What does it read with the headlights on?
Click to expand...

The 11.6 was read yesterday - which was 2 days after the battery was charged and since then it's obviously not been run / charged.... but we've had the ignition on and off loads trying to work out whats been going on (doors been open with interior lights on, radio etc)

The battery is only 6 months old - it's a 5 Year Yuassa x
 
NotAnotherLandRover said:
The 11.6 was read yesterday - which was 2 days after the battery was charged and since then it's obviously not been run / charged.... but we've had the ignition on and off loads trying to work out whats been going on (doors been open with interior lights on, radio etc)

The battery is only 6 months old - it's a 5 Year Yuassa x
Click to expand...
I should charge it again fully with a recondition if that's available.
What are the AH and CCA numbers?
 
Not my area of expertise (the D3) but the later LR's are VERY Voltage sensitive and 11.6 I would consider to be a dead/fried battery that's not holding charge.
My P38 (old hat I know) starts to throw up spurious errors if the volts drop below 12.4 at any point. Once charged properly it is fine.
I would suggest putting a fully charged battery on and doing the hard-reset procedure without trying to do any cranking. See if the disabled state can be cleared, then try a start.
Someone more knowledgeable will be along shortly.
 
NotAnotherLandRover said:
Thank you,

Tested the following pin numbers
CK4 - Battery Feed - 11.6v
CK3 - Ignition On Feed - 11.6v
CF3 - Ignition Feed (Cranking) - 11.6v
CE3 - Transmission Control Module - 11.6v
CM1 / CM2 / CM3 / CM4 - ECM Earths - Good Earths
CJ3 - Switched Earth Engine Control Relay - 11.6v ignition off or on - which obviously is why it's not switching the relay
CL1 / CL2 / CL3 - Engine Control Relay - 0 unless we bridge the relay ourselves at which point we were getting 11.6v

Yes 12.9v on the battery was when it was taken off of charge.

Checked all the fuses last night, and all seem fine.

The scanner is a Snap On Verus Pro - all up to date

and the obvious information I left out which is the car - 2004 Discovery 3 - TDV6 2.7 - ADHD brain letting me down again there!

Thank you, Hannah xx
Click to expand...

hi

many thks for the details , where abouts are u taking the measurements from plse , did u remove the starter battery , rig an extension up in order to access the ecm behind the battery as indeed know that’s in the way , just so we know how ur testing it

would u be so kind to try something for me plse, get a multimeter, ign on, one test lead on the positive battery post and other test lead onto the engine block please , see what reading u get

also if the battery drops below 12 Vdc the system will lock out so to speak so need to ensure that battery is a minimum of 12.6 Vdc before even attempting to start it

when u try and turn the engine over does it click or doesn’t do anything at all , is the red flashing light still shown on the dashboard when u have the ign on plse ,

do u just have one key plse if not have u tried another key

once again apologises for all the questions , we really need to get that red flashing light off otherwise ur wasting ur time and end up pulling ur hair out , just wondering if u may have tried to jump start it, however with the low voltage indication that needs to be resolved first and foremost , we can then go from there

Ps, sorry to hear about ur struggles , can’t even begin to imagine how hard that must be , know u don’t want sympathy, just wishing to say that it can’t be easy and ur find this forum full of many kind and thoughtful people
 
Don't expect anything good from a D3 which has below 12V on ignition, and old battery which was once flat will not be good anymore regardless of the voltage on it after charging
 
Sorry didn’t read the other posts before posting mine, apologises

indeed plus 1 regarding battery voltages , if it drops below 12vdc system will effectively lock out to prevent the starter motor from operating , think I read that’s to stop a starter motor trying to turn over very slowly and where the system needs a minimum amount to start

plus if the red alarm light is flashing the starter motor feed is disconnected by the ecm , there are other security systems in place but of course don’t want to say on an open forum
 
sierrafery said:
Don't expect anything good from a D3 which has below 12V on ignition, and old battery which was once flat will not be good anymore regardless of the voltage on it after charging
Click to expand...

plus 1 , think the lowest mine has ever started was 12.3vdc , also seen ref them being jumped and can cause modules getting a voltage spike causing damage
 
Last edited:
gstuart said:
hi

many thks for the details , where abouts are u taking the measurements from plse , did u remove the starter battery , rig an extension up in order to access the ecm behind the battery as indeed know that’s in the way , just so we know how ur testing it

would u be so kind to try something for me plse, get a multimeter, ign on, one test lead on the positive battery post and other test lead onto the engine block please , see what reading u get

also if the battery drops below 12 Vdc the system will lock out so to speak so need to ensure that battery is a minimum of 12.6 Vdc before even attempting to start it

when u try and turn the engine over does it click or doesn’t do anything at all , is the red flashing light still shown on the dashboard when u have the ign on plse ,

do u just have one key plse if not have u tried another key

once again apologises for all the questions , we really need to get that red flashing light off otherwise ur wasting ur time and end up pulling ur hair out , just wondering if u may have tried to jump start it

Ps, sorry to hear about ur struggles , can’t even begin to imagine how hard that must be , know u don’t want sympathy, just wishing to say that it can’t be easy and ur find this forum full of many kind and thoughtful people
Click to expand...

Thank you GStuart!

With regards to my struggles... it's worse when I am tired and I start getting forgetful and neglectful of the most obvious things... then things like this start to crop up! Ha! But otherwise it's gone 30 years undiagnosed, which is common in women, and have spent my life just thinking I am scatty! On a positive note it means I'm always a bit of a live wire - a bit spicy and unpredictable! It's my partner that needs the sympathy having to live with not knowing what crazy thing I'm going to do next! Haha!!

We were testing at the ECU with the rigged up extension as you described - using a set of jump leads.

When we attempt to turn the key - there's nothing. It doesn't even try to crank - the red light is always flashing, even with the ignition on.

We just have the one key unfortunately. It's been one of those things we've been saying we need to sort out for ages, but just haven't got round to it! Wish I had now!

Just sent him out to do the reading you requested - there'e a voltage drop of 0.02.

Thanks Again GStuart xx
 
NotAnotherLandRover said:
Thank you GStuart!

With regards to my struggles... it's worse when I am tired and I start getting forgetful and neglectful of the most obvious things... then things like this start to crop up! Ha! But otherwise it's gone 30 years undiagnosed, which is common in women, and have spent my life just thinking I am scatty! On a positive note it means I'm always a bit of a live wire - a bit spicy and unpredictable! It's my partner that needs the sympathy having to live with not knowing what crazy thing I'm going to do next! Haha!!

We were testing at the ECU with the rigged up extension as you described - using a set of jump leads.

When we attempt to turn the key - there's nothing. It doesn't even try to crank - the red light is always flashing, even with the ignition on.

We just have the one key unfortunately. It's been one of those things we've been saying we need to sort out for ages, but just haven't got round to it! Wish I had now!

Just sent him out to do the reading you requested - there'e a voltage drop of 0.02.

Thanks Again GStuart xx
Click to expand...

ur so welcome , always a team effort , have a D3 myself and understand they can be very temperamental at times , even making a vicar swear, lol

but there’s plenty of us to help , perfect as understand now what you’ve done, yep battery voltages are well under what’s req as the ecm will look, for a min reading , otherwise as you’ve found, red light will keep flashing , starter motor including the missing relay feeds won’t be there because the ecm are interrupting them

indeed that’s so important to get another key , see if ur scanner will program keys as can buy keys for around £30-40 off eBay , can share some links later after we’ve got this bit sorted out

Also just seen you’ve got ordered a new battery , please don’t think I’m trying to teach u how to suck eggs , check it with a multimeter before fitting it , should be min 12.6 Vdc , then see if the flashing light goes off first , otherwise ur wasting ur time , , if it does see if it will start

plse don’t forget give the battery a full charge overnight , plus not forgetting some chargers ur able to leave the battery in the vehicle, others req battery disconnecting

great u got the diagnosis , at least u don’t have to get stressed over the disco as there’s plenty here to help

Once it’s sorted we can then talk about the key etc if u wish

like others, happy to help , Plse let us know how things go
 
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