rtvtr

Just to clarify on the multimeter tests - I wasn't able to check the power condition light tests - the second bunch of tests on Shahpor's post - only the switch operation. In retrospect if I had been able to get 12V in there I'm sure the fault would have shown.

Every day is a schoolday.

OK - sorry about the delay in reply. I did pull out the switch and the multimeter readings were OK, so I had the car recovered. However I should have tried the eBay route first. In the end my local independent came to the same conclusion after pulling the switch to bits and as the part was not available used locally I got it from eBay - £20 from soton car parts, so I could have saved a few £££.

So my IS is back on the road.

Big thanks to all - particularly madasahatter, Shahpor and Texas.

Folks - big thanks for the help & suggestions. The switch (bit of a pig to remove - if I was to try to do it again, I'd attach Blu-Tac to the front and try to pull it out first, before doing the head unit removal) However it tested OK when removed following Shahpor's instructions, so still scratching my head. I think I'll have to resort to my local independent, but I will come back with the result. 

Croc not crochet!

Thanks. I'll give the switch a go tomorrow after work. I'll need to invest in some small crochet clips first.

Thanks again Shahpor. AM2 fuse is OK, and checking the ODB2 connector again - power is getting there so I'll try changing the switch. I did have the centre console out a couple of years ago to fit a handsfree kit, so I'm OK with that and I'll have a go at replacing the Start switch before I pay for a recovery!

Just to be clear - is there anything in the start button itself that is keyed to the fob, or is it just a RFID reader?

Thanks Shahpor. Is that the 80A fuse in position 21 in the fuse box just in front of the Battery? I can't see visually if its blown squinting through the plastic cover, and I'm a bit outside my comfort zone in disassembling the fuse box - any pointers? However there does not seem to be voltage on pin 16 of the ODB2 connector so I think you are on to the problem.

Of course understanding why the fuse blew in the first place is another question....

Thanks madasahatter

Its a newish third party Battery (95Ah), showing green in the inspection hole.

I've found the other fob - no difference - and checked the clutch microswitch - seems OK. I'm getting 3.8V at the microswitch terminals - not sure if that's normal?

I don't have the second fob ready to hand - its around somewhere :(

Thanks, tried new fob Battery, key on its own, (no other keys or RFID devices - phone, contactless cards, passport, work pass) but still no joy. Fob flashes red when held close to the Start button without any buttons being pressed, which I'm assuming is the RFID handshake. No joy.

However I'm not sure it's anything to do with the key, otherwise I'd get a 'key not detected' when I left the key far from the car. That on its own would point to the clutch microswitch, but I'm not getting the 'depress clutch' message either, which I would have expected.

Maybe a fuse or relay?

Thanks, but I don't think it's quite the same problem.  If it were the clutch pedal microswitch, the start button would be amber to start with - and it is unlit. I'll check it out with a multimeter tomorrow in any case. Manually depressing it didn't seem to make a difference.

I've a odd starting problem with my 2008 IS220d.

Out of the blue there is no response at all when pressing the start button apart from the backlight, no green light, no amber light, no dash warning lights, no message on the dash saying 'key not detected' or 'depress clutch pedal, so I'm assuming the clutch pedal microswitch is not the issue.

Battery appears OK - replaced a few months ago and headlights are bright and  interior lighting and central locking are fine. Fob Battery is new and remote locking is OK, and pressing the key against the start button makes no difference (there is a brief flash of red on the keyfob when I do this, so I'm assuming there is some RFID handshake)

I've disconnected the Battery for several  minutes to reset the ECU - no joy.

I've checked a range of fuses - all looks OK.

Any bright ideas out there?