1990 R129 500sl wit ADS suspension

[Mirko]

Hello everyone.
I have the 500sl with ADS Suspension, since I bought it the button near the light switch never seams to works, I presume it is for lowering and raising the car?
The suspension it's self seams to be ok, apart from that function.
There's no many treads about the ads.
Any advice would be appreciated.
Thanks

 

[LostKiwi]

@Richard Moakes is your man for this.

 

[Mirko]

Thanks, the AFC I'm reading's 3 Body acceleration Sensor 6 Front axle solenoid valves 1 and 14 Steering angle sensor not activated

 

[Richard Moakes]

Hi Mirko,

Steering angle sensor is easy, just turn the steering lock to lock with the engine running. The body acceleration sensor is inside the engine compartment, by the wheel arch, it is an accelerometer and doesn’t normally fail. The front axle solenoid valve is probably a wiring fault or corroded pins in the connector.

Is the yellow MIL light for the ADS illuminated, I.e. the yellow shock absorber symbol in the binnacle?

 

[Mirko]

Hello Richard,
Thanks for response.
The yellow shock absorber symbol is on.

 

[Mirko]

Hello
After the deleting the 3 of the fault codes and driving the car, the came back again.
Does anyone one can give me some advice where to look for?
Thanks

 

[Richard Moakes]

Hi Mirko, I have taken some pictures of the body acceleration sensor, it’s an expensive component to replace so I would suggest unplugging it and plugging it back in again to make sure the connections are secure.

 

[Mirko]

Thanks.
Wiring on mine looks like this.

 

[Richard Moakes]

Hmm, did you add the insulation tape? It looks like someone has been there before?

Don’t open it, I opened a failed one and it’s full of oil and a weight on a strain gauge with very fine connections which you cannot solder. They can be damaged by high amplitude shocks, such as a hammer blow to the bodywork in the area of the sensor.

 

[Richard Moakes]

Basic diagnostic info here https://www.dropbox.com/s/nc28hn4tri51vq5/ADS Diagnostics.pdf?dl=0

 

[Richard Moakes]

The more I look at those wires, the more I think someone has tried to replace the wiring. It looks like mains flex colours to me, not what I would expect on a Mercedes!

 

[Mirko]

Thanks Richard,
I found that there's another sensor on the bottom of the strouts.
They're seams to have same part number?

 

[Richard Moakes]

The other sensor on the suspension arm is different, they measure different G forces and are not the same. I broke the sensor in the suspension arm whilst removing a stuck disk with a hammer, the shock destroyed it.

 

[Mirko]

Ok, I'll try to go through the wires closely.
If I'm not going to find anything suspicious, I'll try to get the second hand one.
Is this can be related to the raising and lowering the car?
Thanks

 

[Richard Moakes]

The raising and lowering will only happen when all faults have been cleared, with the MIL light on, the car is locked in normal height and sport damping.

Do you want me to lookup the part number for the sensor on EPC?

 

[Mirko]

The sensor wiring itself looks good, I"l go through the father wiring tomorrow to see if there's any damage, is there any way to test the sensor?
It would be great if you can lookup.
Thanks

 

[Richard Moakes]

Part number for the turret sensor is A0095422117
Part number for the suspension sensor is A0095422217

The dropbox link I posted has some basic voltage checks you can perform

 

[LostKiwi]

Here's a wiring diagram if its any help:

 

[Richard Moakes]

Better than a link, here is the PDF of the basic checks you can perform

 

[Mirko]

Thanks, so on the first photo there's the power test supply from the module to the sensor (socket 1 and 3) which is reading 5 Volts. Which is correct.
And the reading from the socket 1 and 3 it's supposed to be 2.5 volts and changing when moving.
But there's no value read at all.
So I suspect its shattered?
Thanks