odd starting problem - no light on Start/Stop button

[rtvtr]

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?

 

[madasahatter]

33 minutes ago, rtvtr said:

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?

 

Some body called curtis had similar problem on the forum. I will post his link.

 

[rtvtr]

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.

[madasahatter]

15 minutes ago, rtvtr said:

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.

Does your key fob have any keys attached? Try the fob on its own a mate had a similar thing on a nissan. 

Here is some more things to check out. Do not rule out your new key fob Battery either.

https://www.clublexus.com/forums/is-f-2008-2014/589323-wierd-starting-problem.html

[Texas]

Do you only have one key fob, and therefore cannot try a second key fob to check the one your using is good?

paul m.

 

[rtvtr]

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?

[rtvtr]

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

 

[madasahatter]

10 hours ago, rtvtr said:

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

 

http://lexus2.custhelp.com/app/answers/detail/a_id/8145/~/my-vehicle-has-a-smart-key-and-the-engine-wont-start-when-i-press-the-start

Does your car Battery have the inspection hole. Mine is a blue light to show Battery at full strength. You will need a torch to check it out.

 

[rtvtr]

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?

[Shahpor]

.

 

[Shahpor]

According to the manual you should check the following fuse first:

1. Remove the AM2 fuse from the cowl side J/B RH.
   1. Measure the resistance of the fuse.

2. Standard resistance:

   Below 1 Ω

After that, it recommends removing and check the switch, which unfortunately requires removal of the sat nav/stereo unit.

[rtvtr]

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....

[Shahpor]

No, it is a 15A fuse.  These PDF's should give you an idea where it is:

CSJB-RH.pdf

EngineR-R.pdf

Just pop the cover off the fuse box and pull the fuse out.  It should be obvious if it has blown or not.

As for the OBD2 port, do you mean the DLC3 connector here:

 

I have absolutely no clue when it comes to these diagrams, so perhaps you can tell me why you checked for voltage across that pin?

Thanks.

[rtvtr]

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?

 

[Shahpor]

As far as I can see in the manual it makes no mention of any programming required, so I think it is just plug and play.

I don't know if you want to test it or just replace it, but if you want to test it then the values are as follows:

[rtvtr]

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

 

[rtvtr]

Croc not crochet!

 

[Texas]

Don't you just hate predictive s€x.

paul m.

[Texas]

Text...Text.....meant text!!!!!!!

paul m.😀😀😀😀😀

[Texas]

If your switch turns out to be faulty then I just found this

https://www.ebay.co.uk/itm/LEXUS-05-09-IS250-AUTOMATIC-ENGINE-BUTTON-SWITCH-START-STOP-2004DJ1456/182897925294?hash=item2a9590dcae:g:0mkAAOSwIhxZZMmu

( not being sold by me or anyone I know)

paul m.

[rtvtr]

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. 

[parapilot]

Any news on this?

[rtvtr]

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.

[Shahpor]

You're most welcome

So, even though it tested fine with a multimeter, the switch turned out to be faulty?  How odd.

Glad you got it sorted in the end.

[Texas]

Glad it's all sorted and didn't cost an arm and a leg via main dealer.

paul m.