Gremlins - doors locks, rear windows not working.

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anjo

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Drove my Disco 2 TD5 to the shops and back, but when I went to use it a few hours later I could not gain access from the key fob although the immobiliser had disarmed. I used the key to gain access on the drivers door and the vehicle started, but the passenger and rear door plus tail back door are super locked and when activating the switch on the dash this also has no effect. The rear power windows also do not work along with the rear wiper. The indicators although indicating on the dashboard are not operational on the exterior as does the hazard indicators.

I connected up the Nanocom but it will not communicate with the BCU. Removed the fuse box IDM to check for corrosion on the circuit boards but all is ok with no water ingress. Connected every thing back up but still the faults exist.

Here is a list what is not working.
1. Passenger and rear doors plus tail gate door are super locked.
2. Rear wiper not operational but washer still works.
3. Rear door electric windows not working.
4. External indicators not operational, but indication shown on instrument cluster.
5. Drivers door does not unlock from remote fob, but opens with key.

Help would be appreciated if anybody has had the same problem and what was done to rectify the faults.

John
 
Check fuses as follows, in that order, if one is blown the others are good(usually:cool:)> FL3(50A), F14 - engine bay and the next ones in the interior(IDM) fusebox> F15, F29, F34 .... though the fact that the indicators are showing on dash, immobiliser deactivates but no lights outside and that the doors dont work on dash button points that the BCU works but there is an IDM failure(it's an integrated circuit, comes together with the whole fusebox)...quite common to fail and not cheap at all...unless u go for a second hand from relyable source

It can fail to provide the needed outputs, see the list below
 

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Fuses checked out ok in sequence. As stated I already removed the IDM and took it apart to check the printed circuit board for water damage and it still looks brand new so no water ingress. The BCU will not communicate with the Nanocom so suspecting the BCU could have a fault. I still have more probing about and have to squeeze under the passenger dash to check that the BCU has all the connectors in place as when I removed the IDM one of the connectors was not secured properly. Must be some way of pulsing the door locks to unlock so I can get the passenger door open to get to the BCU.
 
Normally if the ignition is on and u unplug the inertia switch the doors must unlock....but if the IDM has an internal failure u'll not see it anyway... and there was a common issue with the nanocom-BCU comunication i saw somewhere but i'm not the best when it comes about nanocom
 
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Unplugged the inertia switch but still doors will not unlock. Also noticed that front and rear fog lights not working which is pointing to the IDM. I might have to bite the bullet and get a reliable IDM from a breakers.
I intend to check all grounding points associated with BCU and IDM and all multi pin connectors just for assurance. I am not streamline size so will be a tight squeeze on passenger side unless I remove the seat for access. There must be a way to hot wire the doors to unlock?

I am thinking my Disco 2 is playing up as I have a Disco 3 parked beside it in the driveway. Probably looking for sympathy and TLC.
 
See the attachments and i suppose you'll know what to do, unplug C0733 and feed the lock/unlock motor(pins 4 -5), or C0582 pins 5-6 (these are going to C0733/4-5)...how ever it's easyer for you... just take into account that it locks/unlocks by reverting the polarity
 

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I have a copy of the distribution schematic and what you have described matches the schematic. It is raining in Scotland and I have to return to work for the next 2 weeks so when I get back I will deactivate the door locks for entry.
God knows why Land Rover do not install a key switch or emergency button to bypass all the complicated circuitry.

But thanks again for your help.

John
 
Welcome... just disconnect the battery before u give external feeds if u work from the fusebox cos the superlock motor is on other circuit and it's better to not come in conflict with the reverse feed
 
Rule no 1 is always disconnect the battery when it comes to hot wiring vehicle electrics and will be using a motorcycle battery with fuse when de-activating the locks. Vehicle electronics are just unpredictable as probably most owners have found even when jump starting or getting the polarity the wrong way round. Will let you know how I get on in a few weeks when I am back on dry land and the weather hopefully a bit better.
 
anjo said:
Drove my Disco 2 TD5 to the shops and back, but when I went to use it a few hours later I could not gain access from the key fob although the immobiliser had disarmed. I used the key to gain access on the drivers door and the vehicle started, but the passenger and rear door plus tail back door are super locked and when activating the switch on the dash this also has no effect. The rear power windows also do not work along with the rear wiper. The indicators although indicating on the dashboard are not operational on the exterior as does the hazard indicators.

I connected up the Nanocom but it will not communicate with the BCU. Removed the fuse box IDM to check for corrosion on the circuit boards but all is ok with no water ingress. Connected every thing back up but still the faults exist.

Here is a list what is not working.
1. Passenger and rear doors plus tail gate door are super locked.
2. Rear wiper not operational but washer still works.
3. Rear door electric windows not working.
4. External indicators not operational, but indication shown on instrument cluster.
5. Drivers door does not unlock from remote fob, but opens with key.

Help would be appreciated if anybody has had the same problem and what was done to rectify the faults.

John[/
Hi I had same problem arise today to find out it was corrosion on the IDM on the back of the fuse box you have to pull fuse box out and crack it open to check I was lucky to have a spare fuse box here if you replace it you need to let it sit for five minutes with ignition on to communicate with bcu then all was back to normal that's how I got mine sorted hope this helps anyone with the same problem I also had what looked like an 8 with a slash through it come up near the odometer and six chimes when you turned the ignition on.
Click to expand...
 
My IDM showed no corrosion, but in the end I got another IDM from a breakers and now all is ok.
 
:clap2: good choice... u saved time this way... it's effete to chase a fault untill you are not certain that the IDM (or BCU) is good... and if it was good at least you have a spare cos these used to fail anyway;)
 
Don't know whether this will get seen by sierrafery,but here's hoping. His posts regarding the sorting of the IDM and BCU modules were extremely helpful in my tracing and eventually fixing the self same problem. Without his input, I would never have found out where to begin-I have also learnt a great deal more about the control systems within my Disco 2.
Many many thanks-Adrian
 
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