Esp, abs, flashing glow plug warnings!!

[ChillOut]

Like the perverbial Christmas Tree! This happened in the following order:-

1 month ago - ESP and ABS lights came on togther. Went out after next start. Nothing again since until today.

Today, this happened again. Reset them, but soon came back on and stayed on. After about 20 minutes driving got "ENGINE WORKSHOP", shortly followed by Flasing Glow Plug light.

Dropped into local VW/SKODA dealer and asked for a quick diagnostic - no such thing of course so Tuesday is the earliest. But because it was a Skoda dealer and not my usual no help VW dealer he at least listened and said "sounds like your brake lights will be faulty - the flashing glow plug light is for that." He was right, no brake lights. So I bought a brake light switch. I don't beleive in coincidences and did wonder if this was really going to help, given that the entire set of warnings had come up in less than 20 minutes. Sure enough, swapping the switch has made no difference. All lamps still up and no brake lights still.

The plenum chamber is dry, although we have had heavy rain today.

Any ideas chaps?

I have a Gendan KKL lead for use with VCDS, but no XP drivers for it which is really annoying.....

[ChillOut]

Update:

Checked the brake lamps just in case and ALL the fuses (once before I paid £200 for a diagnostic which ended up being a blown fuse which was not one supposedly connected where I had the fault).

No joy there. Just got the correct Gendan drivers so will be onto VCDS shortly and see how we go.

Does anyone know if a detected failure in the ABS system disables the brake lights? That seems like an odd "safety" measure to me. Or do I have two faults generated at the same time, which also seems unlikely?

I wonder if the brake lights have been intermittent for a while as I have had a few flashes from behind recently, butu recently passed its MOT.

[Crasher]

No the ABS does not disable the brake lights, the ABS and engine (on electronic throttle version) must see a dual switch input from the brake light switch.

[ChillOut]

Sorted. Thanks to Winchester Skoda for the advice.

I had fitted the new brake light switch and twisted it until it locked. However, the switch has a fiddly design and a further 2mm of travel was needed to engage what I would call an inter-lock system, which sets the zero point of the switch.

If you need to replace a brake light swicth I suggest removing the lower fascia to see what you are doing and get some light in there - you do feel you are turning a bit too hard and only by seeing you have driven it all the way do you really know when to stop pushing.

Another VW design fault - one more where the part is in stock, cheap, redesigned and the dealer confirms "we get a lot of these go wrong"

The warning lamp system is also poor for this because it does not suggest anywhere in the lamp arrangement, message block or in the service manual that this set of lights could mean you have no brake lights. The fact that it disables the ABS and ESP is, to be honest, less of immediate concern because you can modify your driving to suit, but being without brake lights and not knowing is really very dangerous, given the number of tail-gaters these days who rely on seeing your lights for their reactions.

So why did I get break pressure warning codes in vag-com as well as brake light warning in the VG-COM? I'll explain (using logic - someone will tell me if I am wrong!)

When the switch goes faulty, the car would have no idea if it was looking at the brake ligt switch alone - after all what is the difference between faulty switch and not actually using the brakes? So the system has a brake system pressure sensor (needed in any case for ABS I assume). if it detects increased brake system pressure, but no brake light, it raises a fault. It decides it cannot tell if this is a faulty pressure sensor or brake light switch, so raises a fault on both. If they thought a little harder, they could work out which because the vehicle speed should drop when the brake pressure goes up; so if the pressure is up and speed reduces but no brake lights, then the brake light switch is faulty. If the pressure goes up and the car does not slow, its a pressure sensor fault. Pretty simple Herr Designer.

One final point - this again confirms you should never imagine you have two faults if they both manifest at the same time. Very rarely will this happen and it will be one fault creating a phantom fault code for a number of reasons - I guess frequently as here when the system does not have enough information or good enough programming to decide which one of two or more items is causing the symptoms.