Discovery 3 electrical gremlins *Relocated Thread*

[LRDiscovery3]

Hi all,

I know these posts circulate most forms (as I've tried to read through most) however like most, realise there is some slight iteration which does not specifically apply to mine but if this has been mentioned prior please forgive!

I own a 2008 Discovery 3 HS which I've had for about 6 months which has plagued me with reliability issues (should have hadthe vehicle inspected before purchase I know). Anyways, I do love the Disco with my parents owning one when they first came out and never seemed to have any issues which is why I took the plunge although its been a love/hate relationship to say the least.

Current issue I am having is to do with the suspension.. I think. Ever since I went for 3-hour drive to the Otway’s national park the Disco has developed a suspension/transmission warning issue. The three amigos will appear with the standard transmission/park brake fault, I switch the car off and back on and everything will clear. I'm not sure if maybe the twists and turns of the National Park has done something to the leveling sensors however did recall the back left not sitting aligned with the rest ofthe wheels. On the 3-hour drive back it only faulted twice however now that I'mback in Melbourne it seems to be faulting much more frequently i.e. once every 20 minute drive.

When the faults appear, I pull over as the car begins to lower to access height and turn off. I then turn the car back on and it appears the car has selected off-road height on the selector however not on the cluster. I have to then raise the vehicle into off-road height and then lower it back to normal drive height and then drive off.

I purchased a code reader and have the below current faults

Fault	Description
U0132	Lost communication with ride level control module
P0000	NO DTC DESCRIPTION
U0101	Lost communication with transmission control module
U0100	Lost communication with engine control module/powertrain control module
U0402	Invalid data received from transmission control module
U0416	Invalid data received from vehicle dynamics control module
U0421	Invalid data received from ride level control module
U0401	Invalid data received from engine control module/powertrain control module
U0155	Lost communication with instrument cluster control module
C1A96	Brake light switch circuit
P0504	Brake switch a/b correlation

Note: - I have already changed the brake switch.
- Air compressor can sometime be heard for 30 seconds when starting
- No sagging is apparent when leaving the car for multiple days

I know this is a long-winded story which has been posted various times over however with all the money I've already sunken into this car I need to diagnose these problems myself is possible. I'm not expecting a silver bullet fix but any suggestions, troubleshooting or similar experiences would be greatly appreciated!

My inexperienced theory is something to do with the levelling sensors.



*Edit since other suggestions*
Below is photo of brake light switch whiich I purchased off eBay. I have removed and replaced with original LR part as it didn't seem to be the issue from previous electrical problem I had so no reason to believe it is faulty. Also, when assessing the replacement part from eBay the trigger seemed to almost grind, definitely not as smooth as original LR part.

Have not yet checked Transmission ECU however will this weekend. LR did a full diagnosis of the modules over the course of a few days, so I'd hope they checked that as well.

Also last night when driving, received similar error however this time only 2 dash lights appeared and car did not go into access mode (blurry photo).

The brake lights seem to be working fine and the battery is around 2 months old.

I will see if placing the old brake senser in does anything otherwise very much open to new suggestions.



Cheers
Conah

[loanrangie]

Is the switch a generic one or ford part ?, my ford switch was white and blue so maybe yours is a knockoff. I have a GAP tool so if you are anywhere near me i can read the codes and hopefully pinpoint a more specific component.

[PeterOZ]

at the risk of yet again being jumped by the so called experts I would suggest the following and I know you state the battery is near new however for giggles put it on an overnight charge, do replace the brake switch with genuine LR or ford version. Also give the connectors a good clean with contact cleaner.

I have had issues in the past with brake light bulbs. I have put in cheap ones, narva I think when one blew and got all sorts of weird faults. The ECU as I understand it "pulses" the brake circuit to confirm the globes are function, cheaper globes nave a different resistance value which upsets the return sensed values. Philips globes seem to be ok. Probably other brands as well.

A deep dive with a GAP IID tool would be a good idea, check for pending faults or those that keep repeating from previous cycle. The is a Hexadecimal (base 16) 2 character code in brackets () which when converted to binary gives a lot of additional information including failed previous tests etc.

Unlike others here I am happy to help if needed and won't wack you for asking questions with negative comments about spoon feeding.

Understand its very frustrating, I have just spent a few days sorting out issues with mine to do with hard faults.

All the best.
cheers
P

[LRDiscovery3]

Loanrangie - Looking into it more it seems this may be a knock off part, below is the seller off eBay however the switch came as brown with no markings... Reading the description as well they do mention it is aftermarket so highly doubt is a genuine product. I'll see how it goes for a bit and whether or not it throws the errors again however if it does I'm located in Brunswick and I could definitely drive to help diagnose if the offer is there.

eBay.PNG

PeterOZ - Thanks mate, yes unfortunately if after I check the connections/battery the only real option is a deep dive on a proper diagnostic tool. I can generally wrap my head around mechanical issues but the electrical stuff I've faced with this car has now become an ongoing joke. Mechanics I've seen have told me it’s a solid unit but with each electrical issue I've have makes it hard to trust and not become frustrated.

[loanrangie]

Loanrangie - Looking into it more it seems this may be a knock off part, below is the seller off eBay however the switch came as brown with no markings... Reading the description as well they do mention it is aftermarket so highly doubt is a genuine product. I'll see how it goes for a bit and whether or not it throws the errors again however if it does I'm located in Brunswick and I could definitely drive to help diagnose if the offer is there.

eBay.PNG

PeterOZ - Thanks mate, yes unfortunately if after I check the connections/battery the only real option is a deep dive on a proper diagnostic tool. I can generally wrap my head around mechanical issues but the electrical stuff I've faced with this car has now become an ongoing joke. Mechanics I've seen have told me it’s a solid unit but with each electrical issue I've have makes it hard to trust and not become frustrated.

I'm not far so your welcome to come over.

[letherm]

The is a Hexadecimal (base 16) 2 character code in brackets () which when converted to binary gives a lot of additional information including failed previous tests etc.


P

I tried explaining hex and binary to my teenaged great niece a while back. (I worked in the IT department of a major bank before they realized I was being paid too much and made me redundant in 2002) Absolutely no idea. Gave up when her eyes started to glaze over. She couldn't understand how an old fart knew that stuff.

Apologies for hijacking the thread but your comment brought back fond memories. The guys I worked with and I all still meet once a month for lunch.

Martin

[LRDiscovery3]

Alright well I haven't been able to replicate errors since swapping out Ebay part *touch wood*. Will continue to drive around for at least a couple weeks before I'm satisfied it's actually gone as I've celebrated too early before!

[PeterOZ]

I tried explaining hex and binary to my teenaged great niece a while back. (I worked in the IT department of a major bank before they realized I was being paid too much and made me redundant in 2002) Absolutely no idea. Gave up when her eyes started to glaze over. She couldn't understand how an old fart knew that stuff.

Apologies for hijacking the thread but your comment brought back fond memories. The guys I worked with and I all still meet once a month for lunch.

Martin

I'm an ex RAAF tech and worked in airline/airport IT for many years as a technical project manager. Wrote machine and assembler code years ago. Fun stuff for nerds :-)
Interestingly and not many will know this trivial fact but the Hughes AWG-9 as fitted to the F-111B naval variant (never adopted by USN) and hence into the F14A was all written in assembler.

I digress.

Do get a good code reader such as the GAP IID BT and have a study of the HEX codes as they can offer some helpful clues into failed cycles etc.

Also work out what BUS the ECU that are having issues are on. High speed bus for example.

Get the genuine LR brake light switch, check battery voltages as that is another source of grief and lastly I would start disconnecting every plug you can find and blow out for compressed air then with contact cleaner, insert, remove insert several times and look on the pins for corrosion.

best of British!

LR3 BUS.jpg

[PeterOZ]

Alright well I haven't been able to replicate errors since swapping out Ebay part *touch wood*. Will continue to drive around for at least a couple weeks before I'm satisfied it's actually gone as I've celebrated too early before!

good news


for the uneducated amongst us. Battle of Britain line!

Binary HEX
0000 0
0001 1
0010 2
0011 3
0100 4
0101 5
0110 6
0111 7
1000 8
1001 9
1010 A
1011 B
1100 C
1101 D
1110 E
1111 F