ABS/BAS/ESP warning lit

[ourtomtom]

E Class 200 Kompressor 2002 model saloon

A persistent message occurs to check for a defective lamp. All lamps are checked and found to be okay, but the warning persists. Switch-off the ignition and it indicates 1 malfunction and tells me to check lamps again.

Initially when the battery is hooked up these warnings are lit, but turn the steering lock to lock and they go off

If I then start engine and depress the brake pedal, the ABS & BAS/ESP warning lights illuminate and it indicates 4 malfunctions

Turn off ignition and restart engine all warning lights go out, but check defective lamp warning persists. Turn off the ignition and 1 Malfunction flashes up unless the brake pedal has been depressed when ABS BAS/ESP warning lights illuminate and a warning of 4 malfunctions is indicated. sounds daft but that's what happens Advice welcome

i.e. Note from Handbook The indicator lamp will light up in the instrument cluster and the ABS will be de-activated if the electrical voltage drops below 10volts.

This was the very thing that previously caused the Electronic Control System Unit to malfunction when a dodgy connection in the wiring harness occurred and enabled the local Mercedes dealer to turn the thumbscrews. It created a resistance, reduced the voltage and caused the EMCSU to malfunction.

So it is entirely likely that similar fault in the wiring harness is causing this, particular malfunction of the ABS/BAS/ESP system, which in the end comes down to a faulty manufacturing process and the shylocks are bleeding me dry.

This fault with the ABS BAS/ESP warnings occurred during the first long trip of 100kms or so after the previous electrical connector fault.

I have tried a new stoplight switch but the problem persists, though I'm pretty sure it could be something silly and I’m reluctant to be held to ransom by Mercedes HQ., who are well aware of my sentiments, in this respect.

Maybe I need a diagnostic tool of my own and would be grateful for any advice in respect of what is available and any experience as to whether it works to enable DiY trouble-shooting.
Best regards.
Tom.

 

[television]

You just have a standard ABS fault the BAS and ESP cannot work without the ABS work so a wheel sensor or reluctance ring

 

[ourtomtom]

Does anyone have pics or diagrams, i.e. location of ABS sensor & reluctance ring?

 

[television]

The ABS sensor in the front are built into the wheel bearings, on the rear often just a reluctance ring, this is a toothed ring

Much easier to get a fault code read out first

 

[ourtomtom]

ASB/BAS/ESP Warning Light Problem.

Further diag the curious thing is ASB/BAS/ESP warning lights all go out on engine start, though 1 malfunction and check for defective lamp remains. Though none of lamps are defective. Press brake pedal and ASB/BAS/ESP warnings light up together with 4 malfunctions. That's the mystery any ideas out there?

It would be nice to know the theory behind Mercedes electronics, but I guess we never will.

 

[television]

Replace the brake lamp switch, only £12 and try the car

 

[Pathfinder]

The reluctor rings on the fronts are built into each hub seal, not the wheel bearings.

 

[ourtomtom]

Thanks Television,
Yep it's taking a bit of weighing up, I changed the brake lamp switch but the fault persists. What is mystfying is the dash readout indicates a defective lamp, but have removed and checked all lamps and it still indicates defective lamp. Any other ideas. Tom

 

[Frontstep]

Even though the lamp looks good it may still be faulty get someone to stand behind or mount a mirror somewhere.

 

[television]

Thanks Television,
Yep it's taking a bit of weighing up, I changed the brake lamp switch but the fault persists. What is mystfying is the dash readout indicates a defective lamp, but have removed and checked all lamps and it still indicates defective lamp. Any other ideas. Tom

These are 2 separate faults then, better to pop the car on STAR to see what the ABS fault is

 

[ourtomtom]

This fault persists, looks like I'm getting nowhere anymore suggestions?

 

[whitenemesis]

Wow! Still, after almost a year?

How did the car fair in it's MoT?