09Audi98

Hello, I recently purchased my 2009 Audi S5 and when I bought it, it didn't have any check engine light on and was preforming perfectly. About a month and a half passed and I was accelerating hard and I got a flashing check engine light that lasted 4-5 seconds and than stayed on. I went straight home and threw it on a code reader, it is not a vag-com, but it has a Enhanced Diagnostics for my car and seemed to pull all the codes for the car. I was surprised to see all of the following codes that I got from it. I am not sure if they are all coming from one source or if they are each separate problems that need to be addressed. The codes that I pulled off the car are as followed, P04A3- Exhaust Pressure Control Valve "B" Intermittent(1187), P0A37- Generator Temperature Sensor Circuit Range/Performance(2615), P0A38- Generator Temperature Sensor Circuit Low(2616), P061D- Internal Control Module Engine Air Mass Performance(1565), P0300- Random/ Multiple Cylinder Misfire Detected(768), P0307- Cylinder 7 Misfire Detected(775), P0367- Camshaft Pos.Sensor "B" Circ.(Bank 1) Low Input(871), P06E9- Engine Starter Performance(1769), P0CBE Drive Motor "A" Coolant Temperature Sensor Circuit Low(3262). I have read that the misfires could be from the spark plugs and coils and I plan on replacing them anyways, but I am not sure about all of the other codes that the car is throwing. I know the Direct Injected engines are notorious for carbon build up and I am going to get it cleaned as well, so maybe from that? I am not positive and any help would be greatly appreciated. Hopefully I am able to resolve this issue and save myself a trip to the local Audi Dealer. Thanks again for any help that I get.

findalex

How's the battery? When voltage is low, I sometimes get lots of weird "intermitten" codes.

09Audi98

I have not checked the battery yet, but I will definitely do that. Thank you for the help.

09Audi98

I checked the battery and the level of fluid in the battery was below the minimum line. Should I try and add water in or should I simply replace the battery?

findalex

I've never had a battery that allows me to add water. All the ones I've come across are maintenance free. If Walmart carries the size you need, they have the best deal in terms of performance/warranty. If not, any reputable brand will do. I got mine at the dealer because they sent me a 20% off parts coupon in the mail.

If your car has start and stop, then you may need fancier AGM batteries. Otherwise, I have the regular lead acid in my '13 A5 USA-spec.

ecgarzone

A misfire or multiple misfires on hard acceleration would bring on the flashing CEL. The misfire would also trigger any number of other faults since the dynamics of the system was disrupted under heavy load. Try getting your coils and plugs taken care of first, then record and clear the codes. Drive it and see what results.

09Audi98

I used 2 bottle of Techron Fuel System Cleaner on my car and since I did that I have not gotten any misfire codes. The other day I started my car in the morning and the check engine light came on. I ran the codes and I got P0491 AIR System Insufficient Flow Bank 1 and P0492 AIR Insufficient Flow Bank 2. I cleared the codes and it hasn't been back sense. Today I ran the a Enhanced Diagnostics even though there were no check engine lights and I still got the following codes, P04A3- Exhaust Pressure Control Valve "B" Intermittent(1187), P0A37- Generator Temperature Sensor Circuit Range/Performance(2615), P0A38- Generator Temperature Sensor Circuit Low(2616), P061D- Internal Control Module Engine Air Mass Performance(1565), P0367- Camshaft Pos. Sensor "B" Circ(Bank 1) Low Input(871),
P06E9- Engine Starter Performance(1769), P0CBE Drive Motor "A" Coolant Temperature Sensor Circuit Low(3262). So at this point I am wondering if it is something electrical.

findalex

Did you replace the battery? They last at most around 5 years or so, so you probably need to get a new one soon anyway. If you have a multimeter, what's the voltage reading with the car turned OFF? A fully charged battery should be more than 12.5 volts.

09Audi98

I just tested the battery, I ran the headlights for 2 minutes to drain the surface charge of the battery. I checked the battery after that and it was at 11.99-12.00 volts. Before I drained it, it was at 12.33 volts. I started the car and it only dropped down to 10.56. I thought it should have been a lot lower than that if the battery was towards the end of its life. At least under 10 volts upon startup. I am going to replace the battery in the near future just to rule that out and have peace of mind that I have around 4-5 years with that one.

findalex

Your battery voltage are way too low, I recommend changing it soon. Summer heat kills batteries fast.

Also, I would have your alternator checked. If I read you comment correctly, your alternator is not generating 13.4+ volts needed when the engine is running to charge the battery.

Do a search on car battery/alternator testing or take it to your local auto parts place. They usually have a free battery testing service.