ADS 1 1990 500SL

[Coli]

Hi All, first post. Read many but not finding info I need.

Blink code indicates steering angle sensor faulty, warning light illuminated which can be extinguished, but it illuminates again as soon as steering wheel is turned.

Downloaded test data from a previous thread and getting 12v on correct pin but 10v on control output, maybe not the correct way to describe it, but think that should be lower value, no fluctuation to this on moving steering wheel.

Earth behind centre console has been checked seemed ok but thoroughly cleaned anyway.

Any help on this appreciated.

Col.

 

[LostKiwi]

One for @Richard Moakes perhaps.

 

[Coli]

Hi, yes I imagine so from similar threads. It was he who posted the pdf data sheets.

Thanks.

 

[sausage]

A possible test ?
What are you expecting the 10v control output to be ? If it should be 12v then I would wonder: What would happen if I were to bypass the sensor and put 12v straight on to the output? Would that prove the sensor to be faulty and clear the error or would it cause more problems. Tread carefully, but if you are trying to ID if the sensor is shot, this might help ?

 

[Coli]

Ok thanks.

Think control voltage should be 3v ac, presumably produced by the circuitry, concern is something else is causing error from the steering angle sensor so I do not want to just replace it if something else needs checking. The ecu is out of this as tests are on its input plug connections. On another thread someone had tried three of these but still had fault, no resolution was confirmed there.

Ta

 

[Richard Moakes]

With ADS ecu disconnected, the steering angle sensor should measure >3V AC at the pin to the ECU connector

 

[Richard Moakes]

Voltage info in the attached file

 

[Coli]

Hi,

Thanks for reply and the diagrams.

Have re-tested this to be sure.

Testing as per the datasheet We are getting no reading on AC voltmeter setting and ten volts on DC. On the steering angle sensor test.

Other than the sensor having failed there appears to be no other reason to get these readings.

I had wanted to be sure as I noted from another thread someone trying three of these sensors they had and still had same fault. There was no successful outcome posted to that thread. Presumably they were not new so all may have been faulty, in which case a new one would appear to be the only option.


Thanks.

 

[Coli]

Ok getting somewhere, decided to risk second hand sensor, thanks to RobparkerW123 on ebay, reset fault and light stayed out. Not sure all functioning correctly yet, car did rise when selected but seems to have stayed up, should it rise and fall on the button when stationary?

 

[Richard Moakes]

Ok getting somewhere, decided to risk second hand sensor, thanks to RobparkerW123 on ebay, reset fault and light stayed out. Not sure all functioning correctly yet, car did rise when selected but seems to have stayed up, should it rise and fall on the button when stationary?

Yes, slowly, and best to rev engine to 2000 RPM for things to happen, it builds up the pressure and flow rate of the fluid

 

[Coli]

Thanks for quick reply. Yes heard a bit of a creak when first activated it, has not worked in a while, and could see it rise and went much quicker when revs raised, seems to have stayed up though does it not drop til driven at speed

Ta.

 

[mioba]

glad you are making progress. Keep us posted.

 

[Richard Moakes]

Thanks for quick reply. Yes heard a bit of a creak when first activated it, has not worked in a while, and could see it rise and went much quicker when revs raised, seems to have stayed up though does it not drop til driven at speed

Ta.

The height adjuster rods are operated on a separate hydraulic circuit, it’s driven by a solenoid on the main valve. When they are pulled shorter, the height adjustment valve should allow fluid to flow back to the reservoir. It always seemed slow to me, but it seemed to lower by gravity rather than actively driven lower.

 

[Coli]

Ok thanks again. I will try it out on a longer run at the weekend.

Asr/abs lights on intermittently now, joy! Seems no blink test circut for those, just reading other posts wheel sensors first call

Cheers

 

[Coli]

Abs/asr seems to have sorted it’s self out.

Front is raising correctly, no movement on rear.

Car has been stuck on default hard suspension feels bit more comfortable now but still a bit harsh, maybe rear still on low.

Noticed a bit of movement on front strut top mounts can feel it and see it, this is up and down when putting body weight on and off slam panel (14st) would not expect these to have gone only 67k miles but suppose thirty year old and stuck on hard setting for unknown time. Only mm or so anyone know if this is normal.

Col

 

[Richard Moakes]

Abs/asr seems to have sorted it’s self out.

Front is raising correctly, no movement on rear.

Car has been stuck on default hard suspension feels bit more comfortable now but still a bit harsh, maybe rear still on low.

Noticed a bit of movement on front strut top mounts can feel it and see it, this is up and down when putting body weight on and off slam panel (14st) would not expect these to have gone only 67k miles but suppose thirty year old and stuck on hard setting for unknown time. Only mm or so anyone know if this is normal.

Col

I would disconnect the raise lower rod from the anti roll bar or rear valve and operate the valve lever manually to see if the car raises or lowers.

 

[Coli]

Ok, will do, is this an on/off arrangement, or is there any chance of over pressurising it to watch out for?

Ta.

 

[LostKiwi]

Make sure when you do it there's enough room for you under the car if it's on the lowest setting.
Best done on a ramp.

 

[Coli]

Yes a tricky one, we only have a two post and it will need to be on its wheels, have to have a think.

Ta.

 

[Richard Moakes]

I did it on ramps, agree over pressure could be an issue, it was to ensure the fluid was flowing and the rear valve was working etc.