ABS + ESP + Service Light

[Westyfield2]

Hi all,

I’ve got an intermittent issue, and in fact the previous owner warned me about it when I was buying the car and said that they’d failed to get it fixed and simply put up with it! Unfortunately I am not the type who can just ignore a problem, now I know it’s there I have to get it fixed.

What happens is that midway through a journey the ABS + ESP + Service Lights all come on simultaneously. Turning the car off and on again turns them off. I’ve had the lights come light up on two successive days, but then not come on for two weeks.

When the lights are on the brakes still work etc, but I think I could hear the ABS pump firing every time the brakes were used for the rest of the journey (I need it to happen again to confirm it was the ABS pump and not a noise in my head!)


So I’ve plugged my RSTuner in (Firmware 1.85 with the Mk2Ph2 ABS Module) and below are the errors it found:

error.png

Note that at the time of scanning the lights were not illuminated; the error had happened on a previous outbound journey but then cleared by the return journey home. Next time the lights illuminate on a journey home I’ll leave the car running and plug the RSTuner in whilst the lights are still on and the error is active rather than previously stored.

Any ideas on what might be causing this? Do the error messages mean anything to anyone?

Trying to think about what might be the cause I remembered that one time when the lights came on I had just hit an unavoidable bump. Also because it’s both the ABS + ESP lights coming on I’m trying to think for a common factor between the two systems, and my idea is that both systems use the wheel speed sensors… and a wheel speed sensor missing a rotation could indeed be caused by a bump.

However I obviously don’t want to go round replacing sensors at each corner without knowing it’s a wheel speed sensor at fault and in particular which one!

So yeah, any suggestions on things it might be or ways to narrow it down would be gratefully received!


Cheers,
Ed.

[MicKPM]

Could you "feel" the ABS working thru the brake pedal (It vibrates and makes a nasty grinding noise)?

If so I'd have the wheel sensor targets checked.

[gdw]

Did you sort this? had this happen to me a few minutes ago, restarted car and lights gone off like yours.

[Chris_786]

Happens in mine all the time, it's a brake pedal sensor iirc? Mine shuts off the ABS and traction, I get it when on and off the brakes all the time e.g. sat in traffic.

[gdw]

I seem to have a knocking/tapping noise when i turn to one side, it goes away when I put my foot on the brake pedal?

[aucky]

ABS sensor I believe

[Westyfield2]

Apologies for not replying earlier!


So after clearing the error I had it happen again a couple of times. The noise that I thought was the ABS pump was infact in my head (am I going mad?!) and I gave it some welly to check whether the ABS & ESP were still functioning with the lights lit - they were not.

I then finally had it happen on a journey home so once I got in I grabbed my garage laptop and plugged the RSTuner in with the car still running and the lights on.

active_error.png

As you can see, it was DTC50CE Brake Light Circuit error that was active and bringing the ABS + ESP + Service Lights on.

Some searching on here revealed that this error is because the car has noticed that the brakes are on (from the brake servo I guess) but that the brake lamps are not on . It's warning you that the brake lamp switch on the brake pedal is not working.

I tested the brake lamps vs the pedal on my car and found that the lamps did come on, but I took a good stomp on the pedal to bring them on. Light braking did not bring the brake lamps on. It must have been light braking in traffic that was causing the DTC50CE Brake Light Circuit error.

So I've adjusted the brake lamp switch (guide here) so that now all I need to do is breathe on the brake pedal to make the brake lamps come on.


I haven't yet done enough miles to say that I've 100% fixed it (as I did previously go a couple of weeks without the error) but fingers crossed that's done it...

[MicKPM]

It's a common fault mate... worst case, you'll need a new switch but normally a reset will suffice.

[Westyfield2]

Well today I did not have the ABS + ESP + Service Lights come on... just the ESP + Service Lights.

I guess one light less is progress!

I've plugged RSTuner in and the error code is different, so I'll start a new thread...

new_error.png

[MicKPM]

DF135 is the priority which in this case related to the brake pedal switch. Have you removed it from its secure mount and reset it yet?

[Westyfield2]

DF135 is the priority which in this case related to the brake pedal switch. Have you removed it from its secure mount and
reset it yet?

I've followed this guide and adjusted the switch so that now I literally only have to breathe on the pedal to bring the brake lamps on (previously it took a good stomp). IIRC I've got it only one click away from the plunger being all the way in.


I wonder if I've made it too sensitive and the brake lamps are now coming on when I'm not on the brakes...

[MicKPM]

Does the code come back instantly or does it clear until you touch the brake pedal?

[Westyfield2]

Does the code come back instantly or does it clear until you touch the brake pedal?

I don't know about the error code (I only plugged RSTuner in when I got home) but the ESP + Service Lights today came on mid journey. Both on outbound & return I'd set off with no lights on and had been going a good 10 minutes when the ESP + Service Lights came on (so must have used the brakes by then!) and both times I was not on the brakes at the time the lights came on & wouldn't have been for a good 30 seconds previously (once was going uphill, the other was on the motorway).

[MicKPM]

Might be down to the setup of the brake pedal switch then.

[GazST]

I have done the same (altho i dont have diagnostics) 1st it was ABS/Traction & Service light, i have reset the pedal switch now comes on just the traction & service lights. Is this a new case of a new switch or something more serious?

[aucky]

I had ABS+ESP+SERV lights

Changed brake pedal switch - no change

Changed (by Birchdown) right rear ABS sensor - sorted.

[MicKPM]

Exactly as above... without diagnostics or at least scoping the wheel sensors you're just not going to know as theres loads of items on that system able to throw those lights on.

[w33 brl]

Mines is doing the same but my rear passenger abs senosr is knackered ....so could be your sensor...sorry if its all ready been said im on my android phone

[Westyfield2]

Just to give closure:

ABS + ESP + Service Lights was caused by error codes DTC50CE + DF0135. This was that the brake light switch was not sensitive enough and needed adjusting. "The brakes have been applied but the brake lights aren't on".

ESP + Service Lights was caused by error codes DTC50CD + DF0135. This was that the brake light switch was too sensitive and needed adjusting. "The brakes lights are on but the brakes haven't been applied".



If you keep adjusting the switch as per the guide you'll find the happy medium in-between the two errors. I've now not had the error for months!

[chiscuen]

LOVELY! It saved me a stop with the mechanic.... Indeed it was the brake light switch wich was unpluged.