Thread: Fob not Activating Central Locking.

Originally Posted by Narangga;[URL="tel:3199471"

3199471[/URL]]I replaced the receiver soon after I got mine in an effort to find out why the FOBs wouldn't work. PITA!



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Sucks in a D2 so I can imagine….. especially when it doesn’t fix it.

Originally Posted by SeanC

The fob still starts the vehicle so would it do that if the fob battery was flat?

Yes it should for a D3. As far as I can tell, the fob contains an RFID transponder that manages the immobilizer and that is powered by the inductive loop around the ignition switch. That also charges the battery that runs the RF portion which sends the buttons to the car. They are both independent functions, so a fob with a dead battery will still start the car even if it won't unlock the doors.

Originally Posted by shanegtr

I currently have a fun issue with my FOB - neither of mine work, but take the circuitry of of the FOB case (which I did to check and see if the battery soldering had come loose) and they both work with no issues? Anyone have any wise ideas for this?

If it's a case of "works outside the case and not inside the case" it very much sounds like dry joints. On many vehicles over the years I've seen them anywhere from the batteries, buttons and even around the encoder IC and RF circuit. Try flexing the boards a bit when out of the case and see if you can make it "not work". The case often puts a specific pressure on the board that could be opening the joint up.

Originally Posted by BradC;[URL="tel:3199486"

3199486[/URL]]If it's a case of "works outside the case and not inside the case" it very much sounds like dry joints. On many vehicles over the years I've seen them anywhere from the batteries, buttons and even around the encoder IC and RF circuit. Try flexing the boards a bit when out of the case and see if you can make it "not work". The case often puts a specific pressure on the board that could be opening the joint up.

my soldering station has a reflow gun for fixing precisely that. Even judicious use of a hot oven can help.

Originally Posted by Tins

A Nanocom can test for key detect. Can the GAP tool do this? Could be the RF receiver failed when the change of battery might have spiked it. Total guess, but hey....

I’m thinking the same. I have a fob that I know has a flat battery and it won’t start the vehicle. The time between when the fob worked and I discovered it didn’t was a couple of hours during which time I changed the battery, so I’m pretty sure the fob is fine.

Originally Posted by SeanC

I’m thinking the same. I have a fob that I know has a flat battery and it won’t start the vehicle. The time between when the fob worked and I discovered it didn’t was a couple of hours during which time I changed the battery, so I’m pretty sure the fob is fine.

I've had one fail/stop in that timeframe. All the best with your troubleshooting anyway.

Bought 2 new complete fobs. Swapped the blank key blades for my cut ones. Programmed them with the GAP Tool. Starts the vehicle but still won’t activate the central locking. So unfortunately it wasn’t a flat fob battery.

Have you checked the passenger door sill for moisture in case it's the water ingress to the loom issue?