glow plug warning light


New member
Aug 4, 2017
2003 golf
My glow plug warning light started flashing. After reading a couple of threads I checked my brake lights. Sure enough, a brake light was out. When my left brake light went out a month ago the glow plug warning light did not flash. My burned-out right brake light set off the warning as well as killing my cruise control. As soon as the right bulb was replaced everything went back to normal. This seems very convoluted.


Certified Volkswagen Nut & Vendor
Dec 11, 2001
outside St Louis, MO
There are just too many to list....
The glow lamp flashing is a pretty common way for diesels to cry out for help for things the engineers felt were very important. The gas Volkswagens get an EPC light, and gas cars in general may flash the regular MIL for things like an active misfire.

There's a list floating around here somewhere for all the things that can cause the glow lamp to flash.

As to the "difference" you experienced: some times when a bulb blows, the filament inside falls over and shorts against the other side again, and processors don't like that.

northern diesel

Well-known member
Dec 5, 2023
Northern BC
2006 mk4 TDI Jetta Wagon
Ive had a glow plug light on and a code for brake light switch for a while now.
I need to get around to replacing my 3rd cylinder glow plug, but i have replaced the brake light switch and the code is still there, along with all brake lights being constantly on while i drive (if the headlights are on)
Makes me think its a solenoid.
But i havent been successful in tracking down any evidence to which one might be responsible for that.
As soon as my boost solenoid arrives, i will be replacing it.
But me thinks its a solenoid in the trans perhaps.
VCDS tells me that i have 5 faults found in the trans. All Intermittent.
Trans fluid temp sensor, Brake light switch, Multi-function switch, Engine Control module, and Tiptronic switch.