AUDITT
Glow plug light
Q I am hoping you can help me with an issue I’m having with my wife’s 2008 Audi TT Quattro 2.0 TDI. I am out of ideas and what’s worse my father is out of ideas too! An event that is unprecedented when it comes to vehicle repair. The car has a flashing glow plug light, which comes on after five to ten minutes of running. I have checked the glow plugs and they are all functioning as expected, however Audi also uses the flashing glow plug light as a secondary engine management system fault light. I checked around the car for any obvious electrical faults and checked the condition of the electrical earths.
I also checked the battery voltage both off and while running. I found no cause but on one of many test drives as well as the flashing glow plug light, I also got an engine management light. This gave me a fault code to read, 403, saying I had an EGR circuit fault.
I removed, cleaned, refitted the EGR, and cleared the fault code. On test drive the flashing glow plug light came back but not the engine management light or the fault code. I re-checked all the connections but still got the flashing glow plug light.
After another few test drives, I got the engine management light, again for the fault code 403 EGR circuit. I re-checked the connections and tested the sensors in the circuit. I found no fault with the sensors themselves, however l did find that the feed going to the EGR circuits temperature sensor was only reading 3.4 volts.
My research led me to believe this feed should be 5 volts. As
