Thread: Wheel alignment tip

aah! does he open the tailgate or not...hmmm : watch him work on a D3!

If the D3 is like a D4 in this regard, the tailgate is the only door being open that DOES NOT stop the suspension from going up and down when stationary. I'm not sure if it would be any different while trying to align the wheels.

My info was, tailgate open ,hazards on, car thinks you have a flat and stays put. Made sense to me

Cheers Ken

Originally Posted by roamer

....hazards on .....

Only problem
with that is the battery-drain if they're slow . Pull the neg. off .........
That's what I do in tyreshops , or the susp drops too much.

Originally Posted by Neil P

Only problem with that is the battery-drain if they're slow . Pull the neg. off ......... That's what I do in tyre shops , or the susp drops too much.

As best I can figure, in actual practice, the "leave a door open" instruction, (you choose which one, or all them), does not preclude the auto level program from coming into action; hence, that is the real problem. The door open function is just to inhibit vertical movement while Sir or Madame are entering or exiting and is not for the benefit of the boffins.

The good news is that for the vehicle to drop, the electrically operated exhaust valve within the air compressor has to be powered to open and release air. Hence if all power is disconnected, about the only way air from the air springs can release is thru something broken, (air line lets go, etc), or thru the mechanical pressure relief valve. See the pdf attached, page 79.

As such, if the battery(s) is/are disconnected or fuse F26E in the engine compartment fuse box is removed, then the air system computer is de-energized and the auto level action cannot happen. The 3 should therefore remain at the level where it is. Please note the word "should".

In other words, merely leaving one of the doors open is really not a safe practice. The air system must be de-powered for there to be any chance of it staying put.

http://www.disco3.co.uk/gallery/albu...escription.pdf

Originally Posted by bbyer

As best I can figure, in actual practice, the "leave a door open" instruction, (you choose which one, or all them), does not preclude the auto level program from coming into action

This is definitely the situation. A door open only restricts height changes, eg between access and normal heights. The auto levelling is done to keep the vehicle at a constant height and whilst stationery, is to cater for weight being added or removed.

I thought the dealer needed to put the suspension in 'maintenance' mode which was half way twixt entry/normal height? Every place I've asked about wheel alignments says I have to take it to the dealer before they can do anything.

Dealer said the same, and then complained that they have to drive the car under 40 for it to stay in that mode. Fortunately, its only a few hundred m to the place they use.

I think this thread gets back to my earlier question about the need for "tight tolerance mode" for wheel alignment. It was recommended that a similar effect to TTM could be achieved by having the car idling on a level surface for 5-10 mins, switching off, then pulling fuses 3 and 26 from the engine compartment module, and fuse 10 from the cabin module.

Regards Trif.