Now I'm not complaining as its fixed but...

Where's the link? Other half told me today on journey home the "Check Brake Fluid" light came on... Then "HDC Inactive" then "Suspension inactive". When I got my head outta my hands I went out and tried steering wheel reset. Turning on and off etc but messages still came back.

Topped up Brake fluid reservoir with 200ml (shocked how low consider no leaks and good pads) of brake fluid and all clears itself and all warnings gone!

How does Brake fluid level effect air suspension and Gearbox!!



Tel Accept, some days your the pigeon, some days your the statue!

You could also ask how a humble Stop/Tail bulb could bring the mighty Discovery to its knees, but it can.

Haha really? No way!  Accept, some days your the pigeon, some days your the statue!

HDC uses abs, so probably disabled if fluid low....

As to suspension, no idea.... 2011 Range Rover Vogue SE 4.4 TDV8

Previous cars :
2003 Range Rover Vogue TD6
1999 Discovery Td5 ES
1995 BMW M5 3.8 6 speed
1992 Range Rover 3.9 Efi Vogue
1992 BMW M5 3.8
1988 BMW 735i SE
1989 Ford Sierra XR4x4 2.9i
1981 Ford Fiesta Supersport

According to Storey Wilson (RSW Allcomms) , the ABS and Air Suspension computers are closely inter-related so a fault on the ABS system will almost always trigger an air suspension fault warning too. Current Fleet:-
2018 Discovery 5 3.0 HSE
2021 Ford Ranger Wildtrack
2019 Ford Mustang Bullitt 5.0 V8
1993 Defender 90 200TDI Pickup

Gone - not forgotten
2016 L405 4.4 SDV8 Vogue SE
2012 L322 4.4 Westminster
2004 L322 4.4 V8 Autobiography LE
2000 P38 RR 4.0 HSE (ex Clarkson test car)

mzplcg wrote:

You could also ask how a humble Stop/Tail bulb could bring the mighty Discovery to its knees, but it can.

Boydonegood wrote:

Haha really? No way!

Yep, but it is logical; bad bulbs cause electrical noise on the brake circuits, which in turn upsets ECUs. It can happen on other "premium" vehicles too.

There are always all sorts of faults that can trigger each other because of the way the systems are designed to work together. Easy to see it as a PITA, but it's what makes LRs work so well both off and on road.  Visiting from DISCO3.CO.UK
Discovery 3 TDV6 Auto HSE Zambezi Silver

I would also be removing the covers on the LHS underneath to check the condition of the brake pipes (that is the tank cover and the flat covers on the long run from front to back) If your pipes have not been changed they are likely to be quite corroded and leaking. 200ml is a lot of fluid to lose so keep an eye on the level.

What everyone else says is correct, all the ECUs are linked together in a chain, so if one thing fails, it kicks up errors elsewhere for safety reasons. Therefore if brake fluid is low, you will get an ABS fault, an HDC fault, it will lock down the air suspension (EAS) and this will also get a fault logged in the LCM. Once the issue resolved, check then clear all faults with diagnostics, then check a couple of days later for returns. .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999