waliboy

The story so far: MY2001 Carrera II manual UK model. 2 button key fob stopped opening the doors and unsetting the alarm using one of the buttons but the other button that opens the luggage compartment and unsets the alarm works fine. Tried the following: 1 Replaced the battery after checking the voltage 2 Tried the "bit of card" trick. This is to increase the pressure of the battery against the terminals in the battery holder 3 Tried turning the battery round (this appears to short the negative and positive terminals of the battery holder together). Presumably this is to discharge the chip 4 Tried putting the key in the ignition, turning the ignition on off and then removing the key and pressing the button to reset the rolling code 5 Checked all solder joints and remade any that looked suspect 6 Replaced the switch on one of the fobs. The replacement switch is slightly taller and seems to catch in the fob case so I might swap back 7 Checked the aerial/antenna length and found it to be 95 mm. The frequency here in the UK is 433 MHz which apparently needs a length of 165 mm. 8 Extended the length of the antenna to 165 mm The key works occasionally which leads me to believe that it does not need reprogramming. I've tried it from a few feet away and from 20 feet away just in case it disregards too strong signals (can sometimes happen with infrared). Got my radio frequency scanner and checked the area around 433 MHz and didn't find any spurious signals coming from other local devices. When I operate the fob I see that it's not always the same frequency. Does this device employ frequency hopping as well as rolling code? Have I missed anything? At what point does the ground plane for the antenna earth? My old 928 used to have an occasional problem with the earthing points and I thought I'd give the appropriate one a clean although I don't have any other problems apart from the cigarette lighter does not work (checked the fuse and that's OK). Does this share an earth? Should I try and aerial with a local ground plane? Should I try using a separate power supply that delivers 3 volts just in case there's a lot of internal resistance? Any ideas welcome! W

Hi Dave, tested the removed switch and the unused replacement switch. Both are working the same way, i.e. when pressed they close the contact. Tested the remote on a proprietary remote tester at my friendly Porsche specialist, unfortunately forgot to get the name of the tester. The tester flashes when it sees a signal being sent and it shows a signal is being sent from both of my remotes. Next step is to see if the aerial mod suggested on this forum improves the signal reception. I don't know of anybody who has a circuit diagram. W

Update on the switch switch. Installed the new microswitch and left a gap between the bottom of the switch and the track on the circuit board and still have not cured the problem. Battery carrier next. The trunk release works so can somebody tell me if the luggage compartment (trunk) is separate from the alarm/central locking circuits? If so then I can have a look at the signal reception rather than signal transmission side. TIA W

Hi Dave, changed one of my microswitches - the one that operates the alarm/central locking and it wasn't a success. The replacement is quite easy and I made sure that the switch is clear of the circuit board. I'll be replacing the battery holder next, if I can find a suitable replacement. Let me know how you get on. I can't help thinking that the fault may lie elsewhere. The battery is outputting over 3 volts and the microswitch is closing contact and the little red light flashes as it should but there's no unlocking of doors, no unsetting of the alarm. What surprises me is that the other button that operates the luggage compartment seems to be OK. Is this a separate circuit? Are there two aerials? I can't think of any reason why there should be. Any observations appreciated. W

Hi Dave, many thanks for the info. Do you know who makes the battery holder? The number on the reverse side is 70105003 (see pic) W

I found them in the U.K. I was hoping to get a part number for everybody. Price is about US$8 for two. The switches that I found were slightly different to the ones fitted to the key but they are being marketed as a suitable replacement. I actually fixed my key with a bit of card... I had all the symptoms - the light flashed when either button was pressed, I could use the second button for opening the luggage compartment, the battery was measured at over 3 volts on my meter. It appears that the battery in the fob was not able to deliver the required voltage to send the signal which I find very odd as it was working the luggage compartment release. W

Hi Loren, thanks for the link. I found a local supplier of the micro switches so I'll go see them tomorrow. I have the same problem that is listed above (light flashes on key fob, can open luggage compartment but not main doors/alarm) is it possible that it's an aerial fault? Car is a 996 MY 2001 and the key fob has two separate buttons. W

Hi Loren, where would I find this article? I've googled site:renntech.org +"excellence magazine" but I can't find it and sadly, we don't appear to get Excellence Magazine in the UK. W

Hi Dave do you know the part number for the momentary switches? I'm in the UK and we don't see Excellence Magazine over here. W

I've just had a similar problem. One remote key fob stopped working, then the spare stopped opening the doors but it would still open the luggage compartment (Carrera 2 MY 2000). This WAS confusing! I changed the batteries - nothing. The little red light flashes with the old and the new batteries but the doors and alarm do not unlock/disarm. Took the key fob apart and looked at the contact touching the edge of the battery. I found that by bending this contact a little so that it touched the battery a little better cured the fault. It took several attempts but it finally got BOTH key fobs working. If this contact was only just making contact before then dropping it could have moved this contact ever so slightly and produce the effect you have described. I've dropped my key fobs many, many times and they still work. This may or may not work for you and I have to point out that I am not a trained Porsche technician and you make any attempt at your own risk. Let me know how you get on. W

Try 7657 or 7655 Thanks for that Loren. Tried both with no luck. Just waiting for the 60 minutes to expire to try the '2 rule'. Many thanks for all your help - you really are #1... W No luck. Tried 7653, 7655, 7657, 7659 and 7661. Oh well, never mind! Thanks for trying Loren, much appreciated! Does it matter to where the radio/car is shipped? I'm in the UK. W No, country does not matter if it works then it works if it doesn't then it doesn't. You did get the serial number from the FAQ procedure not off a card in the car? Got the serial number by pressing TP for 10 seconds then turning the right hand knob as per your earlier instructions... W Then you can try the other things in the FAQ. Would you believe it was 7658? Many thanks for trying and getting so close. Kind regards W

Try 7657 or 7655 Thanks for that Loren. Tried both with no luck. Just waiting for the 60 minutes to expire to try the '2 rule'. Many thanks for all your help - you really are #1... W No luck. Tried 7653, 7655, 7657, 7659 and 7661. Oh well, never mind! Thanks for trying Loren, much appreciated! Does it matter to where the radio/car is shipped? I'm in the UK. W No, country does not matter if it works then it works if it doesn't then it doesn't. You did get the serial number from the FAQ procedure not off a card in the car? Got the serial number by pressing TP for 10 seconds then turning the right hand knob as per your earlier instructions... W

Try 7657 or 7655 Thanks for that Loren. Tried both with no luck. Just waiting for the 60 minutes to expire to try the '2 rule'. Many thanks for all your help - you really are #1... W No luck. Tried 7653, 7655, 7657, 7659 and 7661. Oh well, never mind! Thanks for trying Loren, much appreciated! Does it matter to where the radio/car is shipped? I'm in the UK. W

Try 7657 or 7655 Thanks for that Loren. Tried both with no luck. Just waiting for the 60 minutes to expire to try the '2 rule'. Many thanks for all your help - you really are #1... W

CDR22 Type 4467 Ser Y5028991 24 99 TIA W