trackfactory

Saga continues...

Unplugged the MAF while the engine was running and got no change RPMs or anything. engine ran the same. Tried plugging it back in with the engine running and it almost stalled. Replace the MAF with a genuine OEM Bosh MAF. Took the car for a drive all day and no issues. Next morning took it for a drive to the gym and sure enough the studdering and flashing CEL came back. Drove home from the gym and no studdering but at times felt like the transmission shifted hard and studdered a bit. I can tell when the issue is about to happen as the car will start to feel rough on acceleration in higher gears (5 or 6).

Suddenly I noticed something I haven't noticed before. Just before the warning beep would sound and the ESP warning would display, I saw "Audi Hill Hold Malfunction" display. It was so quick, I had to stop and start the car several times just to get what the malfunction actually said. Did a little research on the issue but couldn't find much, especially for the Q7.

Is this problem related?

trackfactory

So on my birthday yesterday, I decided to dig some more into my Q7 issues instead of relaxing for the day. First things first, jacked the car up and took all four wheels off. Removed and inspected the ABS sensors (Due to the ESP/ABS warning lights). Inspected the connectors and and harnesses, found no pinched wires, or loose connectors. Just for the heck of it, I cleaned the crud off the sensors and put them back in. I've ordered all four, so I'll be replacing them as soon as they come in. I also went ahead and cleared out the drain plugs on the driver and passenger sides. When I removed the plug on the passenger side, wasn't too bad, a hand full of water came out. Driver side was worse! quite a bit of water came out (driver side footwell carpet soaked). I'm not sure if there are vital electronics near or under the carpet near the battery.

I had previously replaced the DRL's in the headlamp assembly with LEDs and load resistors. Noticed the other day the resistors were getting EXTREMELY hot to the touch, seemed more than usual, so I removed the LED DRLs, just in case that might be causing my low/short/open voltage errors.

Drove the car around locally for the rest of the day and she seemed to run pretty smooth. No flashing CEL or shuddering. Gas millage even seemed to increase. But still have the annoying ESP/ABS and Hill Hold Malfunction errors. Not to mention the side assist feature malfunction and rear hatch electronics indicating an open hatch intermittently.

Still haven't found any significant info on the Hill Hold malfunction. Although I did find that the brake light switch could actually cause random malfunctions as well. Gonna go for one of those too. So many things in this car that can cause random, totally unrelated issues!

Any insight from anyone who has experienced any one of my numerous problems would be greatly appreciated!

zenekNY

Hi trackfactory!
were you able to track this issue down?

I am experiencing almost the same thing in my B8 A4.
I replaced PCV valve, spark plugs, air filter, cleaned the hell out of the MAF sensor.

I also had intermittent problem with my locks, where they had mind of their own and worked sporadically.
Now my idle is so rough that the engine nearly stalls, I also got electric parking brake and ESP malfunction today.

Any hint would be greatly appreciated, I think it must have something to do with a CAM-bus because I doubt We would be getting
all sort of errors from differet places at the same time.

SamPer

Hi,

I had the ABS ESP light issue in my 2007 Q7 and i got the brakes and rotors including the sensors changed. The light stayed on!! I had to change the Hydraulic Brake Module and the harness on the brake pads to get the lights off. It, in most cases, is the module that causes this problem.
I also had multiple fault codes, including low voltage and MMI issues. Had to get the alternator changed and I ended up spending almost 10k for all of this.
To avoid spending a crazy amount like I ended up doing, I would suggest get it diagnosed at any Audi service center, which would cost around $300-$500 and then use that report to do your own repairs. Or you can use a Foxwell Scanner, works well with Audi. It gives details of all the codes.
Also, remember most Audi cars do not work well with after market parts, but you can still make do with it. After market parts will in most cases not erase the code or the warning lights.

trackfactory

Hi ZenekNY,

I cut the wires to the door locks and they stopped acting crazy, but I'm really not sure if that took care of the rough idle issue. I cleaned the hell out of my MAF sensor, but the issue still cropped up, although it was fewer and further apart, and not as severe. So I decided to replace the MAF. I got a genuine audi/VW part from NAPA, actually less than an aftermarket. That seemed to do the trick. In fact, my gas millage went up significantly, and I could feel a difference in acceleration, in addition to the intermittent rough idle going away.

I still had some annoying minor random electrical indicators, such as the EPS/ABS malfunction light every time I started the car. I would also get a hill decent error only when I put the car in drive for the first time right after startup and accelerated past the 10 MPH threshold when the locks would automatically lock. Couldn't get any recommendations on that one, except that the brake light switch could cause random electrical problems and warning lights. Brand new brake light switch did nothing to cure those. I also have a problem with the lane assist feature disengaging and then not working for long periods of time. I took the switch out and fiddled with it. Thought it might be a cold solder joint on the microswitch board. When I put the switch back in, it worked, to my amazement. That lasted about 2 weeks and then conked out again, so I thought for sure it was the switch. I ordered one from ebay, not sure if it was brand new or not, but after popping in the new switch, it completely stopped working all together. Go figure! My most annoying issue still exists, which is the rear trunk open indication. This is a strange one because I have replaced the microswitches in the rear deck and replaced the latch mechanism on the door side. Sometimes it seems the rear hatch needs adjusting because there seems to be a slightly bigger gap in the seem between the chassis and the door than other Q7s Iv'e seen. A firm push would allow the rear lights in the door to operate, but the open hatch indicator never goes away. Most of the time, if I stick my fingers in the hole and activate the switches manually, they work. But on some occasions, even doing that won't work. Completely random???

Sorry for the delay, hope this helps some.

zenekNY