(ANOTHER) ABS, BAS, ESP warning light issue..

[The Smudger]

Hi all,

I have a minor issue with my wife CLK320. It's a W208 2003 model. The 3 warning messages (ABS/ESP/BAS) sometimes come on in orange but more often than not. It can sometimes be extinguished by turning the steering lock to lock, as if to initialise the steering angle sensor?

Anyone had this and fixed it?

Thanks in Advance,

Steve.

 

[bertb1]

Mine was the abs wheel sensor broken


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[ajlsl600]

I get that if car not used for a while. Lock to lock sorts it...

 

[alexanderfoti]

Do you get it at startup or when driving along?

 

[LostKiwi]

Low battery voltage can cause this issue.

 

[Craiglxviii]

Low battery voltage can cause this issue.

Along with so, so many others...

 

[mioba]

don’t faff about. Get the codes read

 

[The Smudger]

Thanks for the replies chaps/chapesses!

In answer to some of the questions;

"Mine was the abs wheel sensor broken" Good shout, I have read up on these, they seem prone to failure at the rear..

"I get that if car not used for a while. Lock to lock sorts it..." This seems to be favourite, as It sometimes comes on as soon as i start up, and sometimes when driving. I can sometimes get the lights to go out by doing this lock to lock thing.

"Do you get it at startup or when driving along?" See previous reply. Oddly, it came on yesterday on pull away, i did accelerate very sharply, which led me to think it could be something to do with the YAW rate sensor, (it came on the instant i accelerated away, i.e. very harsh Longitudinal acceleration), but that would not account for the fact i can get the lights to go out (sometimes) by turning the steering lock to lock?

"Low battery voltage can cause this issue." Yes, I am aware this can cause issues, but the battery is good, and usually this is not the only problem low battery V will give you. I have had this before, but like someone else mentioned this problem normally brings up a whole load of other problems! The battery is charged quite regularly so i don't think its this?

"don’t faff about. Get the codes read" This is clearly the next move, but i dont have access to a code reader, maybe i'll speak to my old chum Colin! The thing about codes is that whilst it may give you a clue, unless you have some degree of knowledge of the system you can easily end up chasing the fault by changing individual parts until the problem goes away, which can be very expensive!

My personal thoughts are that there is an issue with the steering angle sensor. Reasons for this are as follows;

1. I can 'sometimes' get the lights to go out by turning the steering lock to lock. Maybe this is co-incidental?
2. The steering angle is an important piece of information for the ESP. ESP will look at the information from the steering angle sensor AND the YAW rate sensor, I call this 'desired vs actual'. Only then can it decide which wheel and how much pressure it will apply the brake to.

The thing that i am still trying to reason with is why would, if the steering angle sensor was at fault, the system decide to switch off ABS and BAS as well as ESP?

The wheel speed sensor call is also a good one. If the system cannot see all of the 4 wheel speeds, then it cannot successfully control ABS AND ESP, plus also potentially BAS as it could not know if the extra pressure applied is causing lock up or not?

I'll get the codes read and go from there.

Thanks again for your input people, greatly appreciated.

Best regards,

Steve.

 

[Botus]

this defect will invalidate your insurance, and will make the car unable to control itself under difficult direction manoeuvres

I would therefore describe it as a critical safety system failure and you should not be using on a public road...

the fact you might drive carefully and it might not be a contributing factor in any accident.... is irrelevant...

with the law on death by dangerous driving changing the burden of proof from I was trying to murder someone, to oops I made a small mistake now get 10 years.... I'd only drive gently in good weather conditions to a good indepenant to get it fixed

 

[Botus]

ESP relies on various information, like steering wheel angle, individual wheel speeds and inertia sensor data, to make choice on which individual wheel it might need to activate the ABS on, in an attempt to keep the car going where you'd been pointing it... (before the car noticed data from those sensors suggests some fun is going on re traction and or interesting driver input )

 

[The Smudger]

Thanks for all your constructive comments!

An update..

I ordered a new brake light switch. Sunday AM started the car, all 3 lights flashing straight away..

Remove and fit new brake light switch (about 5 minutes). Start car, NO LIGHTS ON! OK, not going to get too exited so run the car for a few minutes, press brake pedal a few times, turn steering lock to lock, move car up and down driveway, NO LIGHTS ON! So, i have fixed it??

Took the car out for a test drive, 12 miles of mixed driving and still no lights on. So, feeling rather pleased with myself i pulled into a side road to turn round and head for home. As i reverse out of the side road i experience a tiny bit of wheel spin, ALL 3 LIGHTS instantly came on, BUGGER!!!!

So, pulled the car over and switched off. After about 10 seconds i start the car again, ALL 3 LIGHTS ON. Turn steering lock to lock then back to centre, the instant i do this, all 3 lights go out?

So, drive home, another 18 miles and NO LIGHTS ON. Pull up at home on the drive, reverse into the space and BANG! lights on again!

Long story short, the brake light switch was definitely faulty. Before i fitted it the lights were on almost permanently, but now they are only on when i reverse slowly, or drive forwards slowly, but not all the time. And, I can put the lights out EVERY TIME buy lock to lock steering movement. The fault is still there, but i firmly believe there was 2 faults, 1 being the switch, and the other which is still there. I am now going to get the codes read, I reckon ABS sensor???

Yesterday i did 30 odd miles and the lights did not come on at all!!!

I'll keep you all posted.

Best regards,

Steve.

 

[mioba]

Get the code reads by someone with experience.
anyone can get a code reader but being able then to decipher the meanings and locate the fault is the totally another thing.

 

[bertb1]

When my abs wheel sensor was on its way out mine was a intermittent
Turning the car off and on would reset it and all lights would go out but would always come back on


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