Keyless Entry Works - But No Green LED on Start Button

UKKid35 · April 20, 2023

This issue is not exactly the same as

Lexus IS220 start button won't turn green help

but it is similar

Behaviour is the same with both key fobs, no problem with keyless entry, but neither key is recognised by the start button in that it does not go green when pressed

Also it does not go green when either fob is brought close to the button, and it does not make any difference if the clutch is pressed

Obviously pressing the button when the LED is not illuminated does nothing, there are no messages on the dash

It is possible to generate some messages on the dash, for instance you can change the Door Unlock Mode from drivers door only, to all doors, and back again, using the fob buttons

It is also possible to access the Intrusion Senson On/Off menu, using the satellite buttons

At no point does the 'Key Not Recognised' message appear

The fob batteries are new, the car Battery is fully charged, headlights are bright, systems that work without the car in ACC mode work well and are not sluggish

When the fob buttons are used to unlock the car, the Start button text is illuminated in green, therefore the start button is powered, however the LED is never illuminated

Neither fob have been water damaged or dropped, so it seems that whatever links the keys to the ignition has somehow failed, because the keyless entry works fine

I have seen the "POWER SOURCE CONTROL MODULE MPX PSC 89670-53120" mentioned on a US forum, is that module coded or is it a straight swap? It sounds extremely difficult to reach though...

Because of where the car is parked, and because of the electronic steering lock, I doubt it would be possible to get to car towed

What are my options, bearing in mind that the car is worth no more than a grand, and my parents want to sell the car anyway?

veryfedupbunny. · April 20, 2023

sorry to be the bearer of possibly bad news, im NOT a mechanic (for clarity) but i have just had the exact same problem with my is220d sport. after messing around with various autoelectricians - who were, in hindsight, numpties, the latest auto electrian stripped the entire dash out and had to change the remote key sensor, which seems to live right under the windscreen near the centre speaker grill. the worst news was that to change it he had to buy a new immobiliser kit (pre owned, i.e second hand) which includes the steering column and quite a few other modules. car now works again (except for boot remote which he needs to solve) and im down to only one key.

best wishes with it and good luck.

UKKid35 · April 20, 2023

Thanks for your feedback, but it was this that confused me in your post:

Quote

turns out a connection had gone a 'bit bad' and damaged (burnt) a wire which then damaged again the control box..

So my question is, was that thought to be the original cause of the failure, or do you think that happened while various people were working on the car?

Linas.P · April 20, 2023

1 hour ago, veryfedupbunny. said:

remote key sensor, which seems to live right under the windscreen near the centre speaker grill. the worst news was that to change it he had to buy a new immobiliser kit (pre owned, i.e second hand) which includes the steering column and quite a few other modules.

Had to do the same - It is called ID Code box and full list of parts requires is: the ID Code Box, steering lock (column removal not required, one can simply replace PCB inside the lock) and keys. They have to match smart key module part number and power source ECU. Then they need to be programmed to main ECU.

That said my issue was slightly different - my car would start and straight away die. I would start from investigating the button itself. Replacement buttons are not expensive (~£20). I don't believe ID Code box actually controls whenever key is initially recognised or not, it is literally an immobiliser for the engine... so it should allow you to cycle trough the OFF>ACC>IG ON, but just prevents engine from starting... or like in my case - kills it right after the start.

UKKid35 · April 20, 2023

13 minutes ago, Linas.P said:

Had to do the same - It is called ID Code box and full list of parts requires is: the ID Code Box, steering lock (column removal not required, one can simply replace PCB inside the lock) and keys. They have to match smart key module part number and power source ECU. Then they need to be programmed to main ECU.

This sounds like it would cost more than the value of the car - 2006, 112k on the clock with age related exterior marks

Linas.P · April 20, 2023

15 minutes ago, UKKid35 said:

This sounds like it would cost more than the value of the car - 2006, 112k on the clock with age related exterior marks

That is possibility, especially if you ask somebody else to do it. I did it myself and paid ~£200 for the parts and countless hours doing it, because dash has to come out to get to ID Code Box.

Now again - I am not convinced your issue is ID Code Box, although it seems David had similar problem which turned out to be it, so likewise I can't rule it out. Check fuses for Power Source ECU as well... it won't be start button fuse, because you said the button itself lights-up, so it seems it gets power.

UKKid35 · April 20, 2023

2 minutes ago, Linas.P said:

I did it myself and paid ~£200 for the parts and countless hours doing it, because dash has to come out to get to ID Code Box.

I am happy to do work on cars, usually. But this is my parents' car, 120 miles away from where I am, the car lives outside, and it would only be in order to sell it.

I don't see a dash-out job in my future, but I'm also unsure how to get the car removed!

Linas.P · April 20, 2023

No... it is indeed a little bit intimidating at first. After doing it twice now (yes... once turns out was not enough!)... I reckon I can do it in 15 min.

As well you mentioned power source ECU... just to expand on that - yes that could be cause, but again that is not much more than a guess. Reaching it in UK car - you would need to remove glovebox (and then be quite agile with plugs and wiring). Ohhh... and you only need to match the part-number, it may require ECU reset to work, but it is NOT like ID Box which is linked with other modules and must be matching pair.

The circumstances makes me question diagnostics even more. As David said - most electricians are numpties (in my experience as well), but you may call one of those "no repair no fee guys"... yes they are kind of useless, but they work on cars everyday and they might be able to give you second opinion.

The thing is - if you sell it not running, then you can be sure to get less than £500 for it... and if it turns out to be something simple like fuse it will be pity (and that is often the case). I honestly spend more time than it was worth on my car, just because I could not accept selling it for scraps for few hundred £100.

UKKid35 · April 21, 2023

Another module that has been mentioned on the US forums is the Central Body Control Module Unit 8921153020, which looks like some sort of secondary fuse box

Any idea what it's supposed to do?

Beamish · April 21, 2023

I'm not familiar with the manual car but I would expect that there is a switch on the clutch pedal which controls the activation of the green light on the start button.

Perhaps this is faulty?

Just a thought.

UKKid35 · April 21, 2023

Yes that is possible, but I thought it unlikely that the clutch pedal switch and both key fobs developed faults at the same time

veryfedupbunny. · April 21, 2023

23 hours ago, UKKid35 said:

Thanks for your feedback, but it was this that confused me in your post:

So my question is, was that thought to be the original cause of the failure, or do you think that happened while various people were working on the car?

honest answer, im not sure. for a few months leading up to the failure the screen kept flashing up 'no key detected' even while the engine was running, which was odd, so i used my spare key fob, same issue appeared on occasions but car didnt stop or any oother symptom. so i changed key fob batts. car eventually refused/failed to see either fob, but as per the OP had the same symptoms.

i did have a claimed auto elec come to the car after a recoding specialist said recoding wouldnt cure it, he would try it, if i wished, and pay £300 for his time but he felt it would be wasted money. auto elec f**cked about for a few hours and could have damaged something further i agree. he went away to get a wiring diagram and never came back giving excuse after excuse.

2nd guy managed to get the ign to come on, but car wouldnt start, he managed to get code readings which said immobilser system fault. so he changed the immobilser system, inc sterring colum because he reckoned the immobilser sys also effected the sterring lock and electroninc steering, the entire kit only cost £240 so by that stage i told him to do it.

after he did it the car started then stalled. he checked further into the loom and found a short section of bad wire. that had caused a fault to occur in the replacement key sensor, which he then got repaired (hindsight suggests that the original sensor could have been repaired though, i agree) he fixed the bad wire and car has run ok, except for boot remote which he will look into.

so the original cause could have been the bad wire.

Linas.P · April 21, 2023

1 hour ago, veryfedupbunny. said:

auto elec f**cked about for a few hours and could have damaged something further i agree. he went away to get a wiring diagram and never came back giving excuse after excuse.

2nd guy managed to get the ign to come on, but car wouldnt start, he managed to get code readings which said immobilser system fault. so he changed the immobilser system, inc sterring colum because he reckoned the immobilser sys also effected the sterring lock and electroninc steering, the entire kit only cost £240 so by that stage i told him to do it.

LOL... It is so true that it funny and hurts at the same time... every time I have explained this issue in detail to auto-electrician... they tell me they either don't work on Lexus, or don't have time, or some other excuse, few of them told me to maybe ask dealer for diagnostics and then they can repair "whatever they find" - at which point I tell them "if I knew what is wrong I could fix it myself without your help and dealers don't just diagnose the cars for free"... One guy literally came and took my ECU "to be checked and reprogrammed", then went on "holiday" and never returned it (lucky me he took spare one I had)! They only ever come to look at the car if I pretend I am dumb and just say "car does not start don't know why"... then they come spend couple of hours poking at random things and then, fixes nothing and then disappear never to be found again.

So yes - finding decent electrician who knows what they are doing is very hard.

In the end, I pulled out all the electrical diagrams myself, figured out how to use mustimeter and did it myself. Yes it took me 9 months, but I am not sure using electricians from the street would have been any quicker.

veryfedupbunny. · April 21, 2023

1 hour ago, Linas.P said:

So yes - finding decent electrician who knows what they are doing is very hard.

mine was a comedy of farcical errors. to start with the car was on the drive at home, i had booked it in for an MOT anyway and the mot place had ''a good elec we use, but he wont do home visits'' AA refused to recover the car to the pre booked mot because it didnt have an mot. I pointed out to them that when in comes back it will have an mot, and if they recover it it isnt being driven but is going to a pre booked mot 1 mile away from home. they point blank refused, but didnt have an explanation when i asked them if they are such staunch upholders of the law, why did they attend on christmas day to a neighbour who was banned from driving for serious offences and get his car started! their answer was that his car had an mot!!

local garage said their tow truck guy had covid.

his tow truck mate (truck #2) was broken.

first tow truck guy then turned up and wanted to take a scaffolding bar to the steering lock!! no thanks.

lexus dealer said 'it sounds like an expensive repair' but didnt offer anything beyond that.

recoding guy said he would come out - but since lexus dont lose code he would be taking my money for nothing (at least he was honest)

first elec.. what a guy. didnt turn up for first 2 appointments citing family illness.

finally turned up randomly, spent hours doing auto elec black magic type mumbo jumbo, left fuse boxes open, bits of wire all over the place, and said he needed a wiring diag.

i sourced a diag via Jeep site mate, phoned numpty who said he'd come back at weekend. he didnt.

rang him - cant come got covid.

week later. ''im stuck in wales'

days later - ''my van is broken''

a week later '' thermostat has gone on my van''

later that week '' cant get it fixed''

but he saved the best till almost last...

after falling off the radar, ignoring voice mails, texts, whatsaps etc, one day he randomly answered the phone ''im in hospital, ive had a massive brain seizure, not got my phone'' ???? hang about you (insert rude word) if youve not got your **** phone, how the ***** am i talking to you? ''my wife brought it in about half an hour ago. im being discharged (apt for an auto electricain) this afternoon, ill come tomorrow.

tomorrow came and went, unlike him.

then found the other guy, he did more autoelec trickery (possibly including runes and tea leaves) and dismantled the entire cabin from the front seats to the windscreen then announced the car needed to go to his workshop where he could do more. (not unresonable but the car now internally resembled something from a breakers yard, no dash no steering wheel) managed to find a towtruck guy by random chance who had an ex AA recovery truck, he took the car to the workshop, auto elec then got covid, but eventually sent me a video of the car running - sounded like a tractor but it was running.

car reassembled, brought back and running well.

down side is finding someone to make a second fob.

car is having wheels powder coated, should have it back today. now just need to get the boot thing sorted.

Spark plug · April 23, 2023

You need a electronic engineer not an auto spark these days for cars

Linas.P · April 23, 2023

On 4/21/2023 at 1:13 PM, veryfedupbunny. said:

down side is finding someone to make a second fob.

Yes... that is why when I was ordering my ID BOX I made sure to find one with 2 keys already, because I knew the replacement would be ~£600.

veryfedupbunny. · April 24, 2023

18 hours ago, Linas.P said:

Yes... that is why when I was ordering my ID BOX I made sure to find one with 2 keys already, because I knew the replacement would be ~£600.

i got a contact number today for a firm which might be able to make one, if they can i'll share their details.

Lex_utor · April 25, 2023

Wow. This sounds scary. How common is this/these issues?

If that happened to my car I would be at a total loss, considering how much it would cost to have it put right and the time or even finding out the problem. But I have invested too much in the car at this point to just drop it.

But electric/electronic problems scare me. Specially that my car seems to do some funky stuff related to that sometimes. Like now I can't open any windows from the driver's door, apart from the driver's window. But the universal lock is not ON. I figured maybe a fuse. But didn't look yet. But I had a couple of electronic niggles along the way. So the topic in this thread scares me. 😳

UKKid35 · April 25, 2023

7 minutes ago, Lex_utor said:

Like now I can't open any windows from the driver's door, apart from the driver's window.

That's happens if you disconnect the Battery, there's a process documented for re-initialising them

Seems absurd that should be necessary though

normski2 · April 25, 2023

4 hours ago, Lex_utor said:

Wow. This sounds scary. How common is this/these issues?

If that happened to my car I would be at a total loss, considering how much it would cost to have it put right and the time or even finding out the problem. But I have invested too much in the car at this point to just drop it.

But electric/electronic problems scare me. Specially that my car seems to do some funky stuff related to that sometimes. Like now I can't open any windows from the driver's door, apart from the driver's window. But the universal lock is not ON. I figured maybe a fuse. But didn't look yet. But I had a couple of electronic niggles along the way. So the topic in this thread scares me. 😳

Take a look here

Lex_utor · April 25, 2023

Wow, thanks gentlemen! Solved! So easy. But yes. Decidely adbsurd it's needed.

UKKid35 · April 27, 2023

I thought it would be worth getting a quote for a set of Keys/ECUs from 'LexusBreakers' as I was curious about the cost, even though I'm still not intending to do a dash-out job

"Hi sorry we have none in stock at present"

That suggests this is a fairly common problem, surely?

Linas.P · April 27, 2023

Well, that is main problem... set of keys with ECU would be cheaper than buying new keys from Lexus for £600 each, but first of all you have to get matching set, it has to have two keys and then you have to pull the dash out.

When I bought my kit I didn't really had a problem - found few people who were selling ECUs and just told them I need particular matching ECUs with 2 keys from the same car. Something along the lines like here: https://www.ebay.co.uk/itm/225340326605

UKKid35 · April 27, 2023

Why two keys?

Is it impossible to program an extra key if one key is lost?

That set looks like good value, but if you fit it only to find it doesn't work, that would be tragic

Linas.P · April 27, 2023

7 minutes ago, UKKid35 said:

Why two keys?

Is it impossible to program an extra key if one key is lost?

That set looks like good value, but if you fit it only to find it doesn't work, that would be tragic

It is possible to programme the new key... the only problem it costs £600. It is possible to get them done cheaper (outside of dealer network), but it still going to set you back more than just finding the kit with two keys right away. I think it is possible to get new key for ~£135 and get it programmed by independent lock-smith for ~£100-£140 (so we still talking close to £300), but the problem is that many people sell so called "new" keys which aren't actually new and they simply don't work. Now sure allegedly it is possible to "re-seed" used keys (basically reset them to become unlocked, like new), but that again will cost you £150 per key or so. In short when I look at kit with single key I know that there are two possibilities - going to Lexus and getting new key for ~£600 with warranty and done within 1 hour, or buying used key for £50, resetting it for £150 and then programming it for another £140 (I can actually programme it myself, but not everyone can) and that will take 3 days and no warranty. So that is why I would rather just get 2 keys right away.