Hi Dave. No, nothing of the sort.
I did a suspension test by removing the F3 fuse for 48h.
i measured the height of the suspension from the centre of the axle to the wheel arch.
To start with, the rear driver side suspension was higher than the near side by 1/2".
After 2 days, all 4 wheels had lost 1/4". not sure what the significance is.

 

Different heights and vehicle automatically re-adjusting suspension height would led me to check the height sensors as mentioned above, but I would also check for leaks in the air sacks. Maybe an issue with the air compression which in turn is throwing the vehicles computers off balance and causing the rig to behave in some of the ways you have described.

Is it possible that a fault in the air suspension system is causing confusion in the computers and causing the vehicle to "think" it needs to re-adjust the height of the vehicle, thus telling the engine to slow down for optimal speed while raising/lowering of the rig? Sounds like your main problem is with the air suspension itself, so tell the dealer to **** off when they suggest replacing more unrelated parts cause they are just trying to milk you of your money!

 

1/4 inch in two days is nothing to be concerned of at all, and far from the issue here.

I would bet that your suspension fault is not really a fault with the suspension, but with another system that the EAS relies on for data, or possibly purely electrical in nature.

My main concern here is that the dealership diagnosed it as a brake switch the first time around. Going by forums, many people throw a brake switch at it to start, but with actual fault codes that the dealer, or any specialty shop has easy access to, it is usually done for a reason.

This leads me to believe that there was a brake switch fault stored, and a good chance that is the root of the issue.

Unfortunately seeing what faults are stored in what modules is really what I would need to see to be any more help then just speculating on this, as these vehicles are very interconnected with their communication systems. Any chance you can call up the dealer and see if they printed out the fault codes(for either/both visits) and have them attached to the hard copy of the invoice? If so, see if you can get a copy of them(you are very much entitled to them)

 

Thanks for all your imput. I'll call the dealer on monday and see what they've got on file. Is it worth splashing out on a BEARMACH HAWKEYE?

 

I've got the hawkeye, and it will read codes on quite a few modules, but not all. It also requires swapping dongles to read certain modules.

I would recommend something more full featured if you are going to spend that kind of money. It looks like blackbox is very close to releasing an update for the nanocom for D3/D4/RRS etc. From what Colin said over at aulro it should read just about everything and even be able to update code on the modules.

 

Thanks for that. So I guess once you have the error codes you can go back to any independent gararge and pinpoint what the issues with the car are? Is it that simple?

 

So long as the independent garage has a good code reader then yes but if i were you id go with what Jafir recommended. Its always good to have your own diagnostic tools, just try to find the best priced unit that offers the most for your vehicle. Once you are able to read your codes, any problems you have in the future can be easily pin pointed and easier to fix.

 

I wouldn't recommend going to an indy shop that doesn't have the diagnostic equipment to read your vehicle, usually a sign that they don't work on your type of vehicle very often, and much more then basic mechanical might be pushing it.

 

maillotjaun,
This issue could be as simple as an intermittent electrical short in a brake lamp bulb.
I would suggest you replace both the bulbs first, then verify the fault is repaired or not.
If not, you really need to read stored trouble codes. I would recommend you have the vehicle
re scanned for codes. It would also be helpful to have the original stored codes
including the stored codes with unknown mileage ocurrances to accurately diagnose this.
Next step is to know if there are any technical service bulletins that describe your complaint
(with matching stored codes).
2 quite different issues come up here as one message describes your brake lamp switch
fault, and one describes your restricted performance issue.
With the proper codes read and recorded you can begin to pinpoint the issue.

 

Hi your problem is from a red wire splice on the bottom of the right a pillar , this is the wire that supplies 12 volts to the brake switch , there is the famous corrosion on the splice , i have seen about 6 for this month already. also check if there is a water leak on the right side of the vehicle , as this will contribute to this fault,