Hello everyone! 

I have specific problem and maybe somebody has some idea on what is going on.

 

My glow plug light is flashing and through research I found out that it is probably brake switch so I ordered one (febi bilstein 103650 to be exact).

 

I changed it today and after few minutes (or seconds?) of driving glow plug light came up again. Also I should mention that my rear right stop light was not working (bulb was okay, I cleaned contacts and now it is working again). I should also mention that I installed LED registration lights, can they trigger an error?

 

What could it be? Glow plug light came up before (like 10 months ago) but it disappeared as soon as I changed the bulb.

 

Read the codes with cheap ELM327 scanner, it gave me errors unrelated to brake switch.

 

I was also thinking about going to dealership and buying OEM part (20€).

 

Thanks in advance and sorry for my English, I am not a native speaker.

 

 

 You may want to read the following as, while this is a different issue, it highlights that there appear to be specific methods of fitting switches that requires more investigation. 

 

 

 

5 hours ago, foste95 said:

I found out that it is probably brake switch

Key word "probably". Did you actually check that all 3 brake lights had apparently failed as well as the glow plug light flashing before changing the brake switch?

All 3 brake lights are working, only one (on the right, stop light) was not working prior to changing brake switch. I changed brake switch and right light still wasn‘t working. Cleaned the bulb socket and it works fine. 

48 minutes ago, foste95 said:

All 3 brake lights are working

Therefore the issue was not the brake switch.

7 minutes ago, KenONeill said:

Therefore the issue was not the brake switch.

 

Thanks for the help!

 

I will look out for another problems and will update as soon as I find the culprit 

41 minutes ago, KenONeill said:

Therefore the issue was not the brake switch.

 

There are 2 sets of contacts on the brake light switch, one set monitored by the body control module to activate the brake lights (primary but not sole function) one set monitored by the engine ECU to cut engine fuelling when braking amongst other functions.

 

The OP was correct in stating that the flashing glow plug light was probably due to a faulty brake light switch.

 

To the OP, a relatively simple way of checking that the ECU is recieving the correct inputs from the brake light switch (incorrect or absent will cause the MIL light to illuminate) is to left foot brake while keeping the right foot on the accelerator, if the engine power cuts then all is well in regard to the switch.

@J.R. AIUI, if all three brake lights are non-functional and the glow plug light is flashing then the issue is almost certainly the brake switch. If both stated conditionals are not met, then the issue is almost certainly something else.

Not so, there could be no brake light fault or in this case probably one bulb problem but a failure of the secondary contacts which would almost certainly be the reason for the MIL light.

Since I started this topic I'm going to post a solution to my problem.

As far as this problem goes, glow plug light was turning on constantly after driving for a few miles.

 

What did concern me is a check engine light which appeared out of nowhere (with "Emissions Workshop" on the dashboard) after this error happened.

 

Using Delphi diagnostic tool (I know, that was the only thing I had on hand) I got like 5 (yes, five) errors which all were pointing in the direction of diesel particulate filter/anti shudder valve (V157) etc..

Finally I said enough is enough, I went to my local shop and the guy that was working there scanned my codes (using genuine VCDS scanner) and found 3 error codes (compared to 5 which were found with Delphi) pointing to anti shudder valve/diesel particulate filter.

 

 

Today I finally got time to see what is exactly happening and sure enough anti shudder valve was the culprit.

I bought another one and disassembled one that was in my car before and what I saw was my problem

Cleared all codes, car runs fine and no more glow plug light/check engine light.

 

 

Thank you all for the help!