alright, so my MIL/Check Engine light is on....i have a 98 a4 2.8 5 speed quattro with the sport package and 30VAHA motor. I have alot of seemingly unrelated codes. on reccomendation of someone else i put a fuel pump relay in the car. but it didnt fix the problem. wondering if anyone has any ideas or experienced the same problem. All these codes appeared at one time..the DTC's are as follows:

P0134 O2 Sensor Circ.,Bank1-Sensor1 No Activity Detected
P0154 O2 Sensor Circ.,Bank2-Sensor1 No Activity Detected
THESE 2 CODES ARE PENDING, THE REST ARE CURRENT

P1196 O2 Sensor Heater Circ.,Bank1-Sensor1 Electrical Malfunction
P1197 O2 Sensor Heater Circ.,Bank2-Sensor1 Electrical Malfunction
P1198 O2 Sensor Heater Circ.,Bank1-Sensor2 Electrical Malfunction
P1199 O2 Sensor Heater Circ.,Bank2-Sensor2 Electrical Malfunction
P1421 Sec.Air Inj.Valve Circ Short to Ground
P1425 Tank Vent.Valve Short to Ground
P1435 Sec.Air Inj.Sys.Pump Relay Circ. Short to ground
P1472 EVAP Emission Contr.LDP Circ Short to Ground

Any help would be appreciated. Thank You!

 

Engine managment fuse on the drivers side fuse panel.
ECM fuse next to the ECM itself, those are the only two that will cause those fault codes.

 

Alright, i thought i checked my fuses, i guess i missed one...The 30amp "engine timing" fuse was open. So i had an extra one at home i put in, went for a 3 mile ride, fuse was still ok. then went for like a 8 mile ride and it was open again...So i have a repair manual on dvd but it works really slow on my computer..im looking myself but what is on that circuit that can cause the fuse to open? I was told secondary air injection pumps for these cars are common. Any thoughts? anyone know the resistance spec. for the pump across the 2 terminals?

 

any fuse that blows means a bad ground, a positive+ means a connection so I guess you have a bad ground which would cause over voltage,

any fuse/wire that's meant to be a fuse the wires will cause an overload and will short the system out, a 30AMP fuse fail is serious and in most cases its an engine ground

 

the codes you posted are good ( having checked them ) they are a result of a bad cold start ( system not ready ) and heat not up to temp, clear the codes and do a few drive cycles this will reset the ECM

 

I am not an expert by any means, but that explanation doesnt make sense to me. Any fuse that blows does not always mean a bad ground. It is possible to have a short. I wonder if possibly my air pump is siezed or something, which when power was applied to if it couldn't move freely, the motor could draw in excess of the circuit's limit. And the voltage is not the problem...you could have 48 volts to that fuse at 2 amps and it isn't going to open. While i guess the engine ground could be loose it doesnt make sense...it would have other problems i think. Now the codes i posted are right off my professional scantool, with the definitons take from bently publishers, the company that makes the repair manual for audi. It is impossible to set a mil/check engine light simply just because the rediness monitors are not yet ready, otherwise the light would never stay off. The light is on because those objects must be on that "enine timing" circuit. And i could do 100 drive cycles but it wont fix the problem which is the fuse that contines to open. Clearly something on that circuit is shorted...

now i think this is unrelated, but some time after the MIL appeared, i got in the car to start it one day and if i go right from off to start and release the key when the engine starts all the windows will go down. i put them back up and they stay no problem. if i turn the key to on, wait a second, then start the car it won;t do it. it seems unrelated becasue it happpned at annother time but i'm not sure. I would like to fix that problem too but it's not nearly as important. And just so you know, i am not a total car dummy as you might have noticed from the right terms such as an open fuse and the Malfunction Indicator Lamp. i am a student and i'm in the process of becoming a certified technician...I'm just not an Audi technicain and i don't know there querks.