Steering Angle Sensor
My car has been fitted with a replacement rack and currently with the steering wheel straight the sensor reads about 1 whole turn out. I'm hoping you can reset this to 0 degrees with STAR without having to disconnect the rack and remove the clock spring before making an adjustment.
Does your horn work?
Are you saying that when the steering wheel is centered. you don't get the same amount of revolutions turning from one side to the other?
Last edited by Maj. Dundee; Jul 23, 2017 at 06:31 AM.
Ordered a refurbished one from Mercedes for £145 with 12 month warranty and will fit over the weekend.
This post has been helpful: http://danirangelov.blogspot.co.uk/2...eel-angle.html
I suspect the previous owner damaged both the clock spiral and steering angle sensor at the same time when replacing the steering rack.
The Clock Spring was broken when the rack was replaced because it has a contact tape inside it which will snap if everything is not aligned properly.
But the Steering Angle Sensor has no such tape, therefore it is not broken.
Your entire problem is the result of mis-alignment between the steering column shaft and the rack & pinion. Either or both are not aligned.
Good luck with the replacement.
The Clock Spring was broken when the rack was replaced because it has a contact tape inside it which will snap if everything is not aligned properly.
But the Steering Angle Sensor has no such tape, therefore it is not broken.
Your entire problem is the result of mis-alignment between the steering column shaft and the rack & pinion. Either or both are not aligned.
Good luck with the replacement.
My original question was can the steering angle sensor be calibrated to 0 degrees with STAR or similar.
Having spoken to other ML owners here in the UK and the main dealers it would seem the two parts that provide the steering angle position are the Control Unit (N49) part number A164545871680 and the Contact Spiral.
Both of these items have been broken by the previous owner of my car. I replaced the Contact Spiral (Clock Spring) primarily to restore functionality to the steering wheel controls and horn. However, the steering angle fault remained and was diagnosed on STAR as being due to a faulty Control Unit, exactly as per the link supplied in my earlier post. Both of these parts can be broken if you rotate past their end stops, which is why both are supplied locked securely in the centre position and provide instructions on how to position them correctly if out of sync.
Last edited by -AJC-; Jul 28, 2017 at 01:14 PM.
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I took the car to an indy specialist to get the SAS calibrated as my local garage did not have access to STAR. The indy charged me £280 saying they had to refit my steering column correctly as it was 180 degrees out of alignment?? This involved removing the entire column from the car by disconnecting it from the rack etc. etc. Utter rubbish!! I drove the car off the forecourt but the ESP light came on immediately. Took it back to them, reconnected to STAR and now they said the SAS was broken and needed to be replaced. Quoted me another 1-2 hours labour plus the price of the part. Not satisfied with their work so far thought I'd investigate myself.
If you look at any diagram of the steering column you can see it would be impossible to fit incorrectly or upside down etc.
However, should you disconnect it from the rack you should do so in the straight ahead position (steering wheel and front wheels) and ensure you refit in exactly the same position. This is simply to prevent damage to the Contact Spiral (clock spring) and Steering Angle Sensor (SAS) switch fitted just behind the steering wheel.
Both of these parts have a dead centre position and allow approx. 2.5 complete turns of the steering wheel either side. If you were to inadvertently reconnect the column with the front wheels straight but with one full turn of pressure already applied to the springs inside both Contact Spiral and SAS then you would most likely break both these springs as soon as you applied full lock during the recalibration process. To be safe its probably a good idea to remove both Contact Spiral and SAS from the steering column before fitting a new rack incase you damage during refitting.
Here are the parts in question.
Contact Spiral (Clock Spring)
Steering Angle Sensor (N49)
Supplied new these come with a red guard on the Contact Spiral and a piece of white plastic on the SAS, locking each part in the dead centre position. If supplied used you will need to make sure they are in the dead centre position before fitting.
These are very easy to fit yourself with various videos on youtube explaining the procedure.
In my case a broken Contact Spiral meant none of my steering wheel controls worked including the horn. The broken SAS produced further faults and error messages including: ESP inactive, ABS warning, Speedtronic inoperative, Active Light Cornering inactive, ADS Sport/Comfort/Auto switch failed to Sport mode.
A brand new Contact Spiral from Mercedes was £85 + VAT with 2 year warranty. A reconditioned SAS also from Mercedes was £145 inc. VAT with 12 month warranty.
Hope this helps if you have similar warning messages.
Last edited by -AJC-; Aug 6, 2017 at 07:32 PM.
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I had My steering rack changed, as soon as i left the garage i noticed that the ESP light came on.
Is there a way to reset the sensor to make sure its not faulty ? before trying to change it
If the light does not go off, the mechanic broke the sensor replacing the rack.
If the light does not go off, the mechanic broke the sensor replacing the rack.



