Key Fob Doesn't Always Work 02 A4 1.8T Quattro

[renold458]

**If this is the wrong section let me know**

So Im coming from another forum as I wasn't getting any help. I have an 2002 A4 1.8T Quattro automatic and I pretty much copied and pasted my thread I had over there.

Key fob literally works whenever it wants to. I replaced the battery and even then it still doesn't wanna work when I need it to. Oddly enough, the trunk button ALWAYS works, which Im glad because sometimes I lock the car and the alarm sets and if I unlock the car with just the physical key the alarm lights flash until I can get the fob to unlock to disable it, so I have to open the trunk first then unlock the door with the physical key to disable the alarm. Not sure what this is, also just noticed my rear driver side door doesn't lock either.

So any ideas?

[WB650]

Same boat for me, it will work one second then literally the next second it won't, sometimes it won't work unless I'm right next to the car, other times I can be 25ft away and it will work no issue. Replacing the battery usually fixes it for a week or so then it starts up again.

[renold458]

That's pretty much my situation. Last owner did some LED wiring so Im not sure if that has anything to do with it, I really hope not. And I really am trying to stay away from the dealership if I have to.

[OlivierA4]

**If this is the wrong section let me know**

So Im coming from another forum as I wasn't getting any help. I have an 2002 A4 1.8T Quattro automatic and I pretty much copied and pasted my thread I had over there.

Key fob literally works whenever it wants to. I replaced the battery and even then it still doesn't wanna work when I need it to. Oddly enough, the trunk button ALWAYS works, which Im glad because sometimes I lock the car and the alarm sets and if I unlock the car with just the physical key the alarm lights flash until I can get the fob to unlock to disable it, so I have to open the trunk first then unlock the door with the physical key to disable the alarm. Not sure what this is, also just noticed my rear driver side door doesn't lock either.

So any ideas?

since the trunk key ALWAYS WORK, this mean your transmitter (keyfob) working fine. the lock and unlock buttons worn out? have you ever thinking of open up the fob and clean the contacts? is it happen with all they key fob or just one particular one?

Same boat for me, it will work one second then literally the next second it won't, sometimes it won't work unless I'm right next to the car, other times I can be 25ft away and it will work no issue. Replacing the battery usually fixes it for a week or so then it starts up again.

is your key fob has one button that ALWAYS WORK as well? if not, then you might want to check with the antenna receiver on the driver side, top corner back of the car. clean those contacts. there is a link that show how to do it as well.
check out this link it might help
http://www.audizine.com/forum/showth...-Fob-Reception

[WB650]

I've seen that thread. I have an Avant so it's a bit more work than a sedan

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[renold458]

since the trunk key ALWAYS WORK, this mean your transmitter (keyfob) working fine. the lock and unlock buttons worn out? have you ever thinking of open up the fob and clean the contacts? is it happen with all they key fob or just one particular one?

I dont believe the lock and unlock buttons are worn out necessarily, they click fine. I only have one key fob so it just happens to that. How do I clean the contacts?

[lyates1987]

I dont believe the lock and unlock buttons are worn out necessarily, they click fine. I only have one key fob so it just happens to that. How do I clean the contacts?

With rubbing alcohol and q-tips

[dub1audi]

Having the same problem with both my key fobs. Just replaced my battery that didn't fix it. It seems work after being in the ignition for a period of time. Overnight it seems to die bc every morning this week it doesn't work, then after work it works fine.


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[renold458]

Ill try cleaning the contacts later and reply back, but yeah dub1audi when its in the ignition for a little it starts to work but then dies off in like 20 minutes.

[renold458]

since the trunk key ALWAYS WORK, this mean your transmitter (keyfob) working fine. the lock and unlock buttons worn out? have you ever thinking of open up the fob and clean the contacts? is it happen with all they key fob or just one particular one?

How do I remove the circuit board to clean the contacts? It feels like Im gonna break it trying to get it out.

[dub1audi]

So just to add mine has been fine all day today so far. I did run a lot of errands so maybe it just needed some time in the ignition? Let's see what tomorrow brings.


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[diagnosticator]

Scan the Comfort control module for stored fault codes. If there are stored codes, copy and post them back here.

[renold458]

Scan the Comfort control module for stored fault codes. If there are stored codes, copy and post them back here.

I don't have that specific option on my scanner (Vgate VS450). But I've been scanning the sections I can and have been getting this code a lot:

00532 - Supply Voltage B+: Sporadic - Power supply too small

[renold458]

Scan the Comfort control module for stored fault codes. If there are stored codes, copy and post them back here.

Okay if it's the same as "Central Control Module for Central Convenience (J393)" I get code 01330 for "Static - Faulty" and "Sporadic - Power supply too small"

[GTA]

My original fob did the same thing - it would work and it would not work.

I changed the battery in the fob and it still did the same thing. I got fed up and bought a used fob with the key but I tossed the key and just reprogrammed the remote half of the fob to my car. It works every single time since. The only exceptions are when I disconnect the car battery for whatever reason. Every time I do, the fob would stop working completely and I need to wait 2 to 4 days before it 'remembers' my fob again. Weird but it's been consistent after every battery disconnect.

[renold458]

As an update on my side: My car's alternator just died, had a bunch of voltage codes before it so that could've been the culprit. Once the alternator was put back in the fob worked fine. Im going to give it till morning to see if the fob still works, if so then I'd recommend whoever's having the issue to check for electrical codes as they might be a warning sign for things to come.

[renold458]

Update: I've been driving the car for a while and the issue is still happening, so I'm all out of guesses on this one

[OlivierA4]

can you reprogram the key? look like the memory lost its retention overtime

[lyates1987]

can you reprogram the key? look like the memory lost its retention overtime

Iam wondering about this too. I can get it to work but after 30 minutes or so it stops working.Fuckin blows

[renold458]

can you reprogram the key? look like the memory lost its retention overtime

Ive tried reprogramming it through the car, I've heard of people doing it through VCDS but I don't have a license key nor a Windows laptop.

[dub1audi]

So nothing new here. Worked fine for a while the. Went a few days dead and out of blue it started working one day but just that day now dead again for 3 days so far. I thought about changing the battery but haven't yet.


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[ADCS]

I just had this, it is the remote battery.
Buy a new one. Replace it.
Don't use an old battery from something else.

[WB650]

Yeah that usually last for a few months then it starts happening again. IDK why the battery would go bad that fast.

[renold458]

I bought a new battery when this problem started and the issue still persisted, now the car does not want to use the fob for the locks period. The trunk button is still the only thing that is consistent.

[lyates1987]

This seems to be the one thing no one can figure out. Mine will work for up to 30 minutes after I do the key fob dance and then stops working. So annoying. Makes me feel like I'm in the 90s again.

[renold458]

My 99 Altima is literally fool proof with this. Haven't had to change the battery since I've had the car for 3 years. I've tried literally everything but replacing the whole key fob, which seems like the last option and sadly the stealership is where I'm going to have to go for that.

[ADCS]

I bought a new battery when this problem started and the issue still persisted, now the car does not want to use the fob for the locks period. The trunk button is still the only thing that is consistent.

Did you re-sync the remote after replacing the battery?

[renold458]

Yeah as I mentioned above, I resynced through a method with physically using the key with the car. I didn't do it on a software level as I don't have VCDS.

- - - Updated - - -

The lock buttons worked intermittently from then on out, much like before I replaced the battery. Now lock/unlock won't work. Only trunk and panic.

[walky_talky20]

My key fob was intermittent for some weeks, then died altogether. The cause was a missing/ripped "panic" button rubber. Without that rubber present, the internal circuit board was exposed to moisture and other elements. There was some minor corrosion on several apparently "key" components on the board (see what I did there?). This caused intermittent operation, until the corrosion finally ate through one of the traces or component "legs" and then it was dead. Although repair may have been possible, cursory visual inspection did not identify any easy path to a fix. The corrosion was too far advanced.

[renold458]

My key fob was intermittent for some weeks, then died altogether. The cause was a missing/ripped "panic" button rubber. Without that rubber present, the internal circuit board was exposed to moisture and other elements. There was some minor corrosion on several apparently "key" components on the board (see what I did there?). This caused intermittent operation, until the corrosion finally ate through one of the traces or component "legs" and then it was dead. Although repair may have been possible, cursory visual inspection did not identify any easy path to a fix. The corrosion was too far advanced.

Oh stop it you with the puns and ooooo. Interesting, I also have a ripped panic button. But upon inspection of the circuit board when the issue started and recently my circuit board doesn't have any corrosion (from what I can tell). But that is an interesting observation, maybe others in this thread have that problem.

[lyates1987]

My key fob was intermittent for some weeks, then died altogether. The cause was a missing/ripped "panic" button rubber. Without that rubber present, the internal circuit board was exposed to moisture and other elements. There was some minor corrosion on several apparently "key" components on the board (see what I did there?). This caused intermittent operation, until the corrosion finally ate through one of the traces or component "legs" and then it was dead. Although repair may have been possible, cursory visual inspection did not identify any easy path to a fix. The corrosion was too far advanced.

Well this should be exactly what's up with mine. Mines been missing the panic rubber since I bought the car. You think it would work if I swapped the IMMO chip into the other FOB assuming the other FOB wasn't corroded?

[renold458]

If I bought a key fob from ebay, where can I get it cut? Would Lowe's or Home Depot do a decent job? Also how would one go about reprogramming that? Can I do the physical programming with the car or will I have to go to a shop/dealer that has software to do it?

[walky_talky20]

The immo chip is in the key "head". So you should be able to just swap the remote/body portion and be all set. If they come apart like B5 keys. Which I believe they do.

[renold458]

So even if I bought a "complete" fob like this --> http://www.ebay.com/itm/Brand-New-Re...VWjTKh&vxp=mtr <-- Im still going to have to swap that out?

[lyates1987]

The immo chip is in the key "head". So you should be able to just swap the remote/body portion and be all set. If they come apart like B5 keys. Which I believe they do.

Awesome! I appreciate the help!

[walky_talky20]

No Home Depot or Lowes (or Walmart or Ace or any of those chains) has ever had the ability to make these "laser cut" keys in my experience. If you need a blank cut, you will have to call around and find a locksmith. You'll probably have to call all of them. Ask about cutting a key for a 1999 VW Jetta. Don't say Audi, they will see dollar signs. And if you are handling the immobilizer programming (or chip swapping or whatever you are doing), then just tell them that you only want it to open the door. A door-only key. Should be like $10 to get a cut only if you provide the blank.

[renold458]

Awesome thanks, I'll see how that works out if I dabble down that road