2004 Golf Mk4 1.4 Match - Misfire & Brake Switch Errors.

[mlilburn]

Hi,
I am a new member of this forum, but have been reading your posts for a while. I am a Bora TDI driver, but I am hoping someone can help with my wifes Golf Mk4 1.4 Match.

It all started 2 days before our wedding when she was going to collect her dresses and the engine lost power and the EPC light came on, so you can imagine what I had to listen to -

Once we returned from honeymoon, I borrowed an aftermarket diagnostic tool from a mate.

I scanned for errors and found the following:

16955 - Brake Switch Circuit
16684 - Random Misfire
16688 - Cyl. 4 Misfire

I cleared the errors, swapped the cylinder 1 & 4 sparkplugs, started the engine and the EPC light came on, rescanned for errors and found the following:

16684 - Random Misfire
16688 - Cyl. 4 Misfire

The sparkplug did not appear to be at fault, so I cleared the errors, swapped the cylinder 1 & 4 coils, started the engine and the EPC light came on again, rescanned for errors and found the following:

16684 - Random Misfire
16685 - Cyl. 1 Misfire

The coil did appear to be at fault, so I cleared the errors, fitted a new VW coil, started the engine and the EPC light stayed off . The engine sounded normal again, apart from some rattling from the top - will describe later...

The wife then took the car for a spin to the bottom of the street and back again. She said the EPC light came on while she was driving it .

I scanned for errors and found the following:

16955 - Brake Switch Circuit

I can understand this error not being present after I first cleared the errors, as the car never moved while testing and solving the misfire error. I can also understand it reappearing after my wife took the car for a spin...

...But is it a coincidence that the misfire and brake switch circuit errors occurred at the same time, or is it possible that one could have caused the other?

I have read several posts and articles about the brake switch and some people say a faulty one will cause the EPC light to come one. Some also say that a brake switch is faulty if the brake lights are always on, or do not work at all. Our brake lights are working fine.

Can our brake switch be faulty if the brake lights are working ok?

Back to the rattling.

Closer inspection found a low oil level, but not low enough to turn the oil light on. I have topped up the oil and hope a drive to build up oil pressure will circulate it around the head and stop the rattling.

Unless anyone knows of another possible cause, maybe resulting from the misfire.

Any help, advice or thoughts will be appreciated.

Cheers.

[thewol]

hi,
yes there is 2 parts to the switch
1, the lights
2, engine ecu info

change the switch all will be ok then


wol