Disco 3 (LR3) Transmission/HDC/etc Faults

Disco 3 TDV6, 2007, 90-something miles.

OK, I've had the dreaded transmission fault, HDC system fault, parking brake fault and suspension lowered messages. In addition, the engine cuts out. I can still drive the car as the faults clear after a restart or two (apart from one time when I had to replace one of the brake light bulbs to get them to clear).

So, I've replaced the brake switch, and both the brake light bulbs at the same time. I don't have an LR dealer close by, so I put in a Britpart (I know, don't go on at me) switch, and a couple of Ring bulbs from the local motor factors.

But the faults are still coming up. Yesterday, I managed a four hour round trip to Swansea, and they appeared three times. The same thing happens every time - at slow speed, the engine konks out, the messages appear, and a key out engine restart (or two) clears the messages and off I go again. However, one time it was different - first, the engine was very rough on restart (running at 600rpm), and when pulling away on the second restart there was a large grating sound. Also, occasionally, almost always at about 30mph, I can feel the engine start to falter, as if it would stall if the revs happened to be lower.

I am now in two minds what to do. I could either assume that the problem is still in the brake light circuit, and make the journey to an LR dealer to get a pukka switch and light bulbs. Or I could assume that there is another electrical problem and book it into my local friendly mechanic to sort it. Any suggestions, please?

Thanks

I'd say that either way you need to find out what's been happening by getting the codes read whether by the main stealer or by your friendly indie.
Next time you're in Swansea, pop along to Stratstones, I'm sure they would take some coins off you to plug it in.

I am a bit wary of relying on the codes. For example, last month, I had Engine System Fault. The codes were read - MAF sensor and MAP sensor. The cause? Split turbo hose.

it's possible that the codes were hystorical or generic reader used, dedicated tester is needed, or if you fixed the turbo hose it doesnt mean that the MAF and MAP(if the codes are real) were fixed as well and those can give you the missfire symptoms... as about the HDC faults depends on the exact description cos some of them are "priority 3" messages which need no action they are just warnings that a condition for function was not met, see attachment starting from page 32 but better read it all to know what's what on that complicated vehicle

Sounds like the TCM behind the battery has corrosion due to water ingress. Definitely worth a check. Make sure the battery terminals are tight and the earth strap to the body is secure and corrosion free.

The codes for a MAF and MAP are normal, if there's an air leak. The ECU can only show faults from the sensors giving out of spec signals. It can't tell if a physical hose is damaged, only the MAF signal high but the MAP signal is low. That's the same with any ECU, not just the D3 one

An update...

The brake light bulbs have now been replaced with LR supplied ones. £3 each, for flips sake.

And the codes have been read by my local friendly mechanic (using Autodiagnos equipment). The only faults were fuel rail pressure sensor fault, fuel pressure too high. He also checked the battery voltage, which is OK both off and on charge. He's referred me to a specialist

A short search revealed that the Autodiagnos tester is a multi-brand device so not dedicated LR tool, also those fault codes are engine management codes and for your problem there's no reason to scan the engine ECU but the ABS ECU which might not be covered by generic protocol so just confirm was the ABS ECU accessed with that tester and no codes logged there?

No idea. This is why he has referred me - he said that the specialist has better diagnostic tools, and he doesn't want to just start simply swapping out parts in the hope of fixing the problem. He's a good bloke (and didn't charge me for the code read).

Have you checked for corrosion at the terminals of the TCM?

Specialist just rang - he says it is the fuel injector pump - which matches the fault codes read by my local mechanic. £1100 including labour and VAT. If the problem persists, the TCM will be next on my list. At least that's something I can check myself.

Ouch.....

awillemsen said:

Specialist just rang - he says it is the fuel injector pump - which matches the fault codes read by my local mechanic. £1100 including labour and VAT. If the problem persists, the TCM will be next on my list. At least that's something I can check myself.

Click to expand...

This has nothing to do with the title of this thread though.... i'd ask for a second oppinion cos pump failure would give low pressure code not high pressure one and not sensor fault code either... anyway in case that the pump is not delivering well it's replacement is not such big job to pay 600 quid for labour cos the pump is below £500 http://www.ebay.ie/itm/landrover-2-...605836?hash=item3ab0e07f4c:g:H3oAAOSwgQ9V5IPp or maybe a bit more if the vehicle is the Eu4 version(2007 was the transition year) so no need to pay £1100 only if you want to waste money, my mechanic replaced such pump in 4 hours without sweat.... i've seen some cases of this kind of pump failures and all were together with low pressure fault codes or belt tensioner wear.... your money so you decide