Hi, I'm having a bit of an issue with my ST180 remote key fob.

I had some low battery warnings about 2 months ago, I then got some new wheels put on the car (without TPMS), then took the car for one drive and locked it up fine.

3 days later I went to take my car to work, and I couldn't open it. Thought ah damn key fob battery is low, so tried my other fob, again nothing would open. I managed to get in to my car and start it by touching the fob next to the steering wheel and this part works fine.

 

I ordered many batteries of varying brands during the next weeks both Duracell and Panasonic, bought in store so definitely genuine. Again still nothing worked. 

I got a key lock specialist to come out and he said I had a U201F code for external receiver error. I checked this with forscan a week or so later and can confirm this is the case.

 

Having see the code above I bought a module from eBay that was sold as an RF receiver, but changing it today for the one in the centre console it didn't change anything the keys still didn't work (although the units were the same shape/size the one in the car had a white label and different model code to the one I bought, so put the old one back). I tried to get a voltage reading from the wire going to this centre console receiver under the arm rest and I couldn't get any reading, unsure of the connections are too far inside the plug to get a reading though.

 

What else can I try? Could it be something to do with the RFA itself? Where is this located? Getting annoyed with this car now, as if I'm not quick enough I set the alarm off opening it manually. Also just FYI I have replaced both fuses related to this device, and checked all the rest, and they all look fine.

 

Help appreciated as it's making my ownership of the car a stressful one.

 

I fixed this by removing the dome light in my UK car, feeling back into the headliner and removing the RF receiver. There is very little info on this on the internet, so I hope this helps somebody else.

I scraped the pins clean with a flat head screwdriver in case they were corroded, and plugged back in, and now it's all working again! 

I did find while I had this open, that there was also a burnt out blue wire that was jammed in to where the light screws in, and not plugged in to anything. This could relate to another issue I have with my heated screen not working.

Anyone know what it is meant for? 

The single blue wire with a plastic plug?  It goes to the interior light.  Maybe the door open signal wire?  Definitely nothing to do with the heated windscreen.

On 1/8/2025 at 5:08 PM, Seblue said:

I ordered many batteries of varying brands during the next weeks both Duracell and Panasonic, bought in store so definitely genuine. Again still nothing worked.

As an aside, you need to invest in a multimeter, this will enable you to measure the voltage of any battery. KeyFob one should pump out 3.3v, and once it gets to below 2.9v, it'll give issues. Easily obtained for less than £10.

@TomsFocus Thanks, strange, yeah you're right it deffo seems it should be for the dome light, but I couldn't see anywhere it would plug in. The light seems to work as it should too, but it's using after market bulbs. I think one of the past owners must have changed the bulbs, then pinched the wire up in to the metal bracket when pushing it back in, I think because it was touching the chassis it blew the fuse and burnt the wire out. A headliner wiring loom doesn't seem to expensive anyway from ebay.

@StephenFord I have a Fluke volt meter mate nothing wrong the voltage in my car fob battery - I had tested this long ago, before I had tried multiple batteries since that was the most common response on the facebook groups (I was told only buy Panasonic, then only buy Duracell, ended up buying 3 lots, and all had the same voltage lol). This was one of the first things I tested before getting a lock smith out, and then ultimately taking the whole car apart to find the RF receiver. 

50 minutes ago, Seblue said:

@TomsFocus

@StephenFord I have a Fluke volt meter mate nothing wrong the voltage in my car fob battery .

I was confused, you said you had tried a whole series of batteries - if the 1st one you tested was fine, trying different ones was just futile (sorry Tom, have no idea how to delete your '@ name' LOL)

That's an issue for me too.  I recently found out you can just highlight the text you need, then tap, and it gives the option to quote, so no need to delete unnecessary parts from the quote box afterwards.

1 hour ago, StephenFord said:

I was confused, you said you had tried a whole series of batteries - if the 1st one you tested was fine, trying different ones was just futile (sorry Tom, have no idea how to delete your '@ name' LOL)

I just couldn't fathom why it wasn't working all of a sudden, people seemed sure that it was because I didn't use the correct battery brand lol. 

6 minutes ago, Seblue said:

... people seemed sure that it was because I didn't use the correct battery brand lol. 

Well at least you learned that the advice you get on this forum is of a higher standard 🤣