Key Fob Problem

[tae111]

I have a 2011 Audi A4 Premium Plus with 79,000 mikes. The other day my key fob stopped operating the door locks and trunk release. It will start the car but nothing else works. I thought it might be the battery as it has never been changed. I replaced the batteries in both my regular fob and the spare but they still won't operate anything but starting the car. Any idea what may be the problem?

[Smac770]

Scan for DTCs. See if the car is already aware of broken things. It appears Advanced Key was Prestige only that year. So that simplifies things. The buttons on the key fob initiate RF transmissions that are picked up by the roof antenna and routed to the RF looking wire on the J393 in the right rear. The key detection in the ignition slot is a completely different mechanism.

[tae111]

I plugged in my code reader and it is showing no codes. Where is that wire located? The roof antenna seems to be functioning properly for the radio.

[tae111]

It looks like I will be bringing it in to the dealer this coming week. I'm hoping it won't be something major. I'm sure they will exact their pound of flesh either way.

[earhythmic]

I’ve had to do this a few times, your key needs to be re-linked. There’s various ways to do it, here’s one:

1# you take one key put into ignition turn on.

2# close door, lock it with the key hole on driver side,with the key you want to program.

3#once it's lock take the key of the door out press the open button once or 2 or 3 or 4 times depending on which key is being reprogrammed(for the seats memory)you will see your side blink every time you press ,wait 6 secs press again once.take the other key in ignition out.

close the door and try locking with the reprogrammed key.

Or

1.Take one key/remote (key B) and put it in the ignition and turn the ignition ON (to the "accessory-on" position - don't start the car).
2.Close and lock the driver's door with the other key/remote (key A) while the ignition remains on.
3.Take the key A remote and press the "UNLOCK" button ONCE only - alarm will 'beep'/lights flash, but door will remain locked.
4.Wait for a slow count of 10.
5.With key A, unlock and lock the door again (using the key not the remote).
6.Test the remote by pressing the "UNLOCK" button again - door should unlock.
7.Open the door and turn ignition off and back on again using the key A this time.
8.Continue the procedure for the second remote - close & lock the door with the key B (leaving the ignition on).
9.Take key B remote and press the "UNLOCK" button TWICE - alarm will 'beep'/flash each time button is pressed but door will remain locked.
10.Wait a count of 10 again.
11.With key B, unlock and lock the door again (using the key not the remote).
12.Test the remote by pressing the "UNLOCK" button again - door should unlock.
13.Remove both keys, close the door and perform a final retest by locking and unlocking the car with both remotes.

If this doesn't work, repeat WITHOUT steps 5 & 11.

[Smac770]

The roof antenna is not involved with the AM/FM reception. A separate antenna in the roof unit is used for Sirius sat radio.

If it's just an OBD-II code reader, that's not going to likely be sufficient, especially if it's just a powertrain reader. VCDS is the normal scan tool standard, OBDeleven as an alternative, for VAG products (VW, Audi, etc).

The J393 is in the right rear, behind the cargo side panel. But you're not going to be able to determine much by looking at it. Codes from the J393 is what is of interest.

I'm not familiar with the process quoted by earhythmic. It's not an issue I've had to delve into. I'd start, again with VCDS, by just looking at the fob ids the J393 reports are currently adapted to it. There's only so much you can do without a more suitable diag tool such as VCDS. Activating a previously adapted key is also something you can do in VCDS, but it appears there's also the two fob tango you can try as well.

[tae111]

The roof antenna is not involved with the AM/FM reception. A separate antenna in the roof unit is used for Sirius sat radio.

If it's just an OBD-II code reader, that's not going to likely be sufficient, especially if it's just a powertrain reader. VCDS is the normal scan tool standard, OBDeleven as an alternative, for VAG products (VW, Audi, etc).

The J393 is in the right rear, behind the cargo side panel. But you're not going to be able to determine much by looking at it. Codes from the J393 is what is of interest.

I'm not familiar with the process quoted by earhythmic. It's not an issue I've had to delve into. I'd start, again with VCDS, by just looking at the fob ids the J393 reports are currently adapted to it. There's only so much you can do without a more suitable diag tool such as VCDS. Activating a previously adapted key is also something you can do in VCDS, but it appears there's also the two fob tango you can try as well.

I will try the fob tango to see if that does anything. I suspect there is some other problem since it happened all the sudden and affected both key fobs. I'm guessing there is a receiver of some sort that is to blame. If I take the physical key out of the fob and use that the electronic locks and security seem to work fine.

[tae111]

What's amazing is with all the searching I have done I can't find any one who has had this exact problem.

[Smac770]

My bad, central locking is not on the roof unit. The roof unit does have key fob RF, but only for the remote aux heat. Central locking RF is on the window glass (upper left side of rear window for a sedan).

The central locking aerial is connected to the R112 aerial amp on the left D-pillar (not the R52 aerial unit on the roof), then the cable runs from that to the J393. But this is where running a scan would be the start. Is the car already saying there's an issue with the R112 connection. Is the radio having any issues with the R112 (as the R112 also handles AM/FM1), or is it only the J393.

So could be a break in the R112 unit itself, or maybe a break in the connection from the R112 to the rear glass.

So a scan and visual inspection of the R112 would be the two things to do.

[tae111]

I spoke with the service dept. of my local Audi dealership and they said it sounds like the programming was somehow lost with the fobs. I'm bringing it in Wednesday. They said it will take about an hour to fix. I will say that about 3 weeks ago there was another issue with the key. I got a key warning light on the dash. At that time I swapped out the key fob with the spare and that went away. It's my wife's car and really doesn't get driven much. Maybe once a week and then only about 10 miles. Other than that it sits in the garage. Still looks like a new car inside and out even though it's 11 years old.

[chuckb825]

Strange question did you check your MMI to make sure your locks were turned on? I can't quite remember but I have a 09 A4 premium plus and I have a setting in the MMI for the locks. So I'd check that just for the heck of it.

Sent from my SM-F926U using Audizine Forum mobile app

[Theiceman]

i had this problem and posted about it .. i had to reset with VCDS and was good to go , after days and days of the monkeying around. with keys in ignition and doors.

Mine was a B7 but this might help .

https://www.audizine.com/forum/showt...?highlight=key

[tae111]

Chuckb825 Thanks I didn't even think about doing that. My wife's out with the car but when she gets home I will check that out.

[tae111]

OK so I'm embarrassed to admit this but when I replaced the batteries I put them in upside down and I did it with both key fobs. I brought it to the dealer this morning and 5 minutes later they brought it back around. I said fixed already? The service manager, who I have known for years, laughed and said don't feel too bad it happens quite a lot. Anyway problem solved and no charge from the dealer.

[StuckAntichris]

Happens to the best of us. Glad you got out of the dealer without paying anything haha

[Smac770]

Always a win when it turns out to be simple and quick to fix.