MR2 Roadster Owners Club

The Workshop => Maintenance, Problems & Troubleshooting => Topic started by: xsarahx on January 11, 2011, 13:53

Title: URGENT help needed ! key fob/alarm.
Post by: xsarahx on January 11, 2011, 13:53
I really hope someone can help me with this as its driving me nuts !!

Replaced what i thought was a flat battery in my keyfob (it has been working intermittently for a few days) Tried to open the car but it wouldnt work with the new battery in, even though the light was flashing on the key fob buttons, took the battery out and tried in my spare key fob but it was exactly the same. Took the battery back to halfords to have it tested and they said there was nothing wrong with the it.  This morning it tried open the car with the keyfob but again it wouldnt work so i unlocked the door with the key setting the alarm off straight away, tried to turn the alarm off with the fob whilst sat in the car but no joy, lights flashing but alarm still going off. Started the car up and the alarm was still going off !!

May have ONE faulty key fob but surely both of them cant be ? Is there some sort of morse code style thingy i can do to disable the alarm manually ?

Cant drive the car and my neighbours are going to kill me if i dont get it sorted !  s:evil: :evil: s:evil:
Title: Re: URGENT help needed ! key fob/alarm.
Post by: spit on January 11, 2011, 14:01
Something that has come up before is interference from remote doorbells and such-like that screw up the fob's transmitter. Have a read here:  l viewtopic.php?f=31&t=31941 (http://mr2roc.org/phpBB3/viewtopic.php?f=31&t=31941) l

So before your neighbours kill you, check with them to see if they got any new toys for Christmas?  s:D :D s:D  

And be vigilant in case there's something more sinister going on.
Title: Re: URGENT help needed ! key fob/alarm.
Post by: xsarahx on January 11, 2011, 14:13
Yes i have just been reading previous threads here but i would say the last 2 weeks its been happening in all different places, so i dont think anything like that is affecting it.
Title: Re: URGENT help needed ! key fob/alarm.
Post by: mrzwei on January 11, 2011, 15:06
If the light on the key fobs comes on when you press either the lock or unlock buttons and you have a new CR1616 (or equiv.)lithium battery then that should rule out the fobs as the problem.
Operating with just the the key can't disable the alarm
Title: Re: URGENT help needed ! key fob/alarm.
Post by: xsarahx on January 11, 2011, 17:05
Yep lights on the key are flashing when pressed and ive checked the battery and its the correct one so i guess thats not the problem,

Any more ideas what it could be ?

Looked through all my paperwork and security booklet but it doesnt say alot.   s:( :( s:(  

Also been all around the car pressing the buttons at various angles and pointing it at different bits inside the car but its ignoring me completly !! ............... little bugger !
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Anonymous on January 11, 2011, 17:56
Does it work in other locations?
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Nchillin75 on July 3, 2014, 09:12
Hi all,

I have just had the same problem as below. 2003 Facelift MR2 Mk3.

Both fobs working fine, then this morning nothing. Fob light works suggesting battery ok, central locking and alarm won't disable. Manual entry via key sets the alarm off.

Re-programmed the key but this appears to be more to do with the immobiliser than the alarm and central locking. Car starts fine and did prior to re-program. But alarm keeps going off as long as doors are open and movement inside. In nutshell, I can't drive it.

Did anyone find a solution to this?

Figure its between the fob and the receiver on the car.

Note: Checked the microswitch to ensure the clicking sound was present indicating the microswitches are working fine but it will neither unlock or lock on both fobs.

Need help urgently!

Many thanks

Neil
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Wabbitkilla on July 3, 2014, 09:21
does it work ok away from home?
If you sit with the door open until the alarm stops sounding you should be able to start and drive the car (memory is sketchy here as it's a while since it happened to me)
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Nchillin75 on July 3, 2014, 10:11
hi ya

mmm, think I tried that but as soon as I closed the door or created movement inside the alarm went off again. Engine starts but as mentioned the alarm does appear to be a separate entity to the immobiliser.

this negates the ability to drive from house to somewhere else unless I can justify the flashing lights and siren  s:) :) s:)

I did here mention of interference and driving it somewhere to test but I've not seen a post suggesting this actually works?

very frustrating for me and the neighbours whilst testing various theories  s:) :) s:)
Title: Re: URGENT help needed ! key fob/alarm.
Post by: StuC on July 3, 2014, 10:29
Reading some other old threads, perhaps it is worth having a look at the alarm unit itself. Thread with pictures of how to locate it  here (http://www.mr2roc.org/phpBB3/viewtopic.php?f=31&t=37338&p=448749&hilit=alarm+unit#p448749). This issue has come up a few times now.
Title: Re: URGENT help needed ! key fob/alarm.
Post by: phils99 on July 3, 2014, 10:50
you have to program the key twice (well I did when I got a new one!)

Firstly to pair with the car immobiliser to enable the key to start the car and secondly with the radio frequecies to enable the key to lock/unlock the doors and enable/disable the alarm.

Have you carried out the second programming sequence?

not sure how to attach a doc here, but if you PM me your email, I can send you the doc I used to pregram the fob buttons to work.
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Nchillin75 on July 3, 2014, 10:59
Hi Stu

Many thanks - will take a look. Still figure this comes down to a transmission problem from fob to receiver. Question is, where is the receiver? By the looks of those threads the sounder is in the frunk. Assume the receiver or whatever accepts the fob transmission is located there too?
Yup I've seen a few posts on this but no fixes as such. Much like wireless I.T networks its the dark art of radio signals, they either work or they don't and figuring out why is nothing short of a miracle. Fob or receiver is going to cost and the appropriate law dictates you fix the wrong end  s:) :) s:)
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Nchillin75 on July 3, 2014, 11:01
Hi Phil

I did re-programme my key twice but no change....is there a different method for the fob compared with the key itself?

I used the open door closed door insert key routine which was confirmed by a clunking of the locks. The key always started the engine (key to immobiliser) prior to re-programming and after but the fob would not unluck or lock the car / switch the alarm off.

Will drop you a PM. Hoping you have a different routine for the fob  s:) :) s:)
Title: Re: URGENT help needed ! key fob/alarm.
Post by: phils99 on July 3, 2014, 11:05
yes...the second programming gets you to press the key fob buttons after the open/close door/insert key routine.
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Nchillin75 on July 3, 2014, 11:09
ah yes that was at the end of my script.

is there a defined time limit after the clunking locks confirmation?

I did try but clearly I may have mis-timed it or not followed that element accurately. What is the confirmation from the car once done? or is it that everything goes silent and the doors work once more  s:) :) s:)  returning me to a ridiculously happy MR2 driver
Title: Re: URGENT help needed ! key fob/alarm.
Post by: StuC on July 3, 2014, 11:15
Quote from: "Nchillin75"Hi Stu

Many thanks - will take a look. Still figure this comes down to a transmission problem from fob to receiver. Question is, where is the receiver? By the looks of those threads the sounder is in the frunk. Assume the receiver or whatever accepts the fob transmission is located there too?
Yup I've seen a few posts on this but no fixes as such. Much like wireless I.T networks its the dark art of radio signals, they either work or they don't and figuring out why is nothing short of a miracle. Fob or receiver is going to cost and the appropriate law dictates you fix the wrong end  s:) :) s:)

(http://i1186.photobucket.com/albums/z373/Hodjay/c6d047b5.jpg)

(http://i1186.photobucket.com/albums/z373/Hodjay/2d642f3f.jpg)

(http://i1186.photobucket.com/albums/z373/Hodjay/7b2f360d.jpg)

This is the unit I was talking about. I believe that it is the sensor, that's why I suggested this as a possible problem.
The siren itself, in it's stock position is under the spare wheel. Other members have moved it out of this position and located it under the frunk plastics. Just a thought whilst you are experimenting with various bits and bobs, might be to stuff a towel over the alarm to make it less noisy. So your neighbours aren't on your back as much.

Hopefully Phil's key stuff works first though.
Phil - Is it different to this (http://www.mr2roc.org/phpBB3/viewtopic.php?f=47&t=23563) stuff?
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Nchillin75 on July 3, 2014, 11:31
hi, yes towel idea is an excellent plan  s:) :) s:)

if you inserted a link or an image in to that last post I can't see it. were you highlighting where the sensor was located?
Title: Re: URGENT help needed ! key fob/alarm.
Post by: StuC on July 3, 2014, 11:34
Quote from: "Nchillin75"hi, yes towel idea is an excellent plan  s:) :) s:)

if you inserted a link or an image in to that last post I can't see it. were you highlighting where the sensor was located?

There are pictures in my last post and a link in the one before.
Are you view the forum on a PC or a mobile device using tapatalk?
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Nchillin75 on July 3, 2014, 12:08
Hi Stu - PC

can't see the images - got the link for the key square dance which differs ever so slightly to routine I put on for the neighbours this morning. does seem to be many variations.

2003 onwards is my specific
Title: Re: URGENT help needed ! key fob/alarm.
Post by: StuC on July 3, 2014, 12:13
Quote from: "Nchillin75"Hi Stu - PC

can't see the images - got the link for the key square dance which differs ever so slightly to routine I put on for the neighbours this morning. does seem to be many variations.

2003 onwards is my specific

Weird!   s:( :( s:(    s:cry: :cry: s:cry:  

 m http://i1186.photobucket.com/albums/z37 ... d047b5.jpg (http://i1186.photobucket.com/albums/z373/Hodjay/c6d047b5.jpg) m

 m http://i1186.photobucket.com/albums/z37 ... 642f3f.jpg (http://i1186.photobucket.com/albums/z373/Hodjay/2d642f3f.jpg) m

 m http://i1186.photobucket.com/albums/z37 ... 2f360d.jpg (http://i1186.photobucket.com/albums/z373/Hodjay/7b2f360d.jpg) m

Links to images above
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Anonymous on July 3, 2014, 12:18
Just a thought here, the alarm unit there is under the plastics that can fill up with water due to blocked drains etc. Could we be seeing the results of water damaged electronics by any chance?
Title: Re: URGENT help needed ! key fob/alarm.
Post by: StuC on July 3, 2014, 12:19
Nice deduction there Meeerrrk  s;-) ;-) s;-)
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Nchillin75 on July 3, 2014, 13:16
Stu - can now see - many thanks
Title: Re: URGENT help needed ! key fob/alarm.
Post by: StuC on July 3, 2014, 13:17
Thank goodness for specsavers!  s;-) ;-) s;-)   s:lol: :lol: s:lol:
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Nchillin75 on July 3, 2014, 13:18
I'd agree with the water theory, if the central locking worked but the alarm didn't or vica versa. Central locking and the alarm must be on two different circuits to a point...as both work normally but cannot be activated by the fob, suggests sensor no?

or as we possible mentioned the fob has lost its connection to the car.

question: are the key and the fob both based on the same chip? apologies I don't know how key coding works. But I would imagine as their is only one circuit board in the fob, they are the same? so if the key can be coded to the car but the fob can't, gonna have to presume the fob does work but I'm rubbish at synchronising the last section of the key coding element. i.e. the two button fob push.
Title: Re: URGENT help needed ! key fob/alarm.
Post by: StuC on July 3, 2014, 13:19
Might be time to whip it out and check the connections then.
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Nchillin75 on July 3, 2014, 13:43
question: are the key and the fob both based on the same chip? apologies I don't know how key coding works. But I would imagine as their is only one circuit board in the fob, they are the same? so if the key can be coded to the car but the fob can't, gonna have to presume the fob does work but I'm rubbish at synchronising the last section of the key coding element. i.e. the two button fob push
Title: Re: URGENT help needed ! key fob/alarm.
Post by: phils99 on July 3, 2014, 13:59
the key has a build in transponder the same as a non button key, one stage of the programming is to "pair" up the key transponder to the ignition switch.

The second part is to then pair up the radio transmitter for the push buttons to the car. this is the part I think the guys need to do to get the fob working.

The whole security system works from a seperate ECU which connects to the cars ECU.

I know this as I change a cars full security system out as my car only has the grey key which means you cannot reprogram any keys.

So I bought a full set off ebay with the fob key, ignition switch, ECU, door lock barrels, floor levers lock and the glove box lock (he didnt have the rear box locks available) and had to replace mine with all of that!

afterwards it all worked great!
Title: Re: URGENT help needed ! key fob/alarm.
Post by: StuC on July 3, 2014, 14:29
Interesting there Phil that you dont mention the alarm unit (the one under the bins) in the bits you have replaced.
Title: Re: URGENT help needed ! key fob/alarm.
Post by: phils99 on July 3, 2014, 14:32
you know, I cant remember if I did replace this, but I think I must have done, this is the interior sensor and I would think be a generic part not specifically coded to a car.
Title: Re: URGENT help needed ! key fob/alarm.
Post by: phils99 on July 3, 2014, 14:41
reason I say I cant remember, is because I also bought a second MR2 PFL and this didnt even have an alarm fitted!

I had to buy a 2 button key fob pre cut and pre transponder coded to my car from CTP (£130!!) as I only had a black key for the car.

I then found the full wiring loom wiring, ECU, interior sensor, siren and the "plungers" for the bonnet and engine lid as a kit on ebay and fitted these, which then required coding...endless hours of opening and closing the door and inserting the key in the ignition!.....so you see I have had endless fun with the Toyota alarm systems in the MR2!!

But if anyone else on here has an MR2 without an alarm fitted, this can be retro fitted and I also have a brilliant doc from Toyota detailing how to do it and all parts needed. Take note that Toyota no longer supply the retrofit kit as myself and Chris from CTP found out the hard way!
Title: Re: URGENT help needed ! key fob/alarm.
Post by: StuC on July 3, 2014, 14:41
I would have thought it was a generic part too.
Not sure how in depth people have looked at this component before.
Title: Re: URGENT help needed ! key fob/alarm.
Post by: phils99 on July 3, 2014, 14:51
yes...it is pretty well hidden, but it also has an adjuster on it so you can decrease/increase the sensativity.

For those who dont know, when the alarm is enabled, this "hidden" unit sets up a wave field in the interior of the car, if someone reaches in to say grab your bag from inside, it will detect an obstruction in the wave field and set the alarm off...clever!
Title: Re: URGENT help needed ! key fob/alarm.
Post by: carolineasb on July 3, 2014, 15:14
Think the interior "waves" are only when you have done 3 "clicks" on the locking button?
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Nchillin75 on July 3, 2014, 15:14
well - with enormous amounts of sound dampening towels and blankets I will tackle this tonight. Can we just confirm the correct method of pairing for the 2003 onwards? I appreciate there are several documentations of this.

I also bought a cr1616 just in case it is the battery lol
Title: Re: URGENT help needed ! key fob/alarm.
Post by: phils99 on July 3, 2014, 15:17
cant you just open the frunk, remove spare wheel and pull the wire out of the siren? This will allow you to work on it (indicators will flash to show alarm is going off)
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Nchillin75 on July 3, 2014, 15:18
Phil

is it also possible based on the separate transponder and radio transmitter to find someone with the alarm ECU (lovely if he had working fobs with it) replace it and pair a new set of fobs?

The key transponder wouldn't change so the Engine ECU wouldn't need replacing...
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Nchillin75 on July 3, 2014, 15:42
ref wires out of siren - another obvious solution  s:) :) s:)  will do
Title: Re: URGENT help needed ! key fob/alarm.
Post by: StuC on July 3, 2014, 15:46
I just wondered if having it connected to the system whilst you are diagnosing it is important. There is more than a couple of wires going into the sounder, so it's not just a power and ground.
Title: Re: URGENT help needed ! key fob/alarm.
Post by: phils99 on July 3, 2014, 15:56
Neil,

the key, transponder and fob is all one piece, so maybe, you could get another alarm ECU and using the supplied key fob take the insides out of it and put it in your key fob....

But, honestly, if you follow the programming guide, you should be able to get the one you have working unless it is actually not sending a signal but just lighting the little light on the key everytime you press a button.
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Nchillin75 on July 3, 2014, 16:03
that programming guide, is there definitive answer on the method for 2003 onwards. Sorry to repeat. I've seen three versions now.  s:) :) s:)
Title: Re: URGENT help needed ! key fob/alarm.
Post by: StuC on July 3, 2014, 16:06
As far as I know it works for all years.
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Nchillin75 on July 3, 2014, 16:11
c. 3 times for CONFIRMATION mode.

out of interest what is this mode?

add is obvious - rewrite suggests replacing a key if the ECU is full

and I figure you need to go through the full process of coding the key before coding the transmitter?

you can't just skip to the transmitter?
Title: Re: URGENT help needed ! key fob/alarm.
Post by: StuC on July 3, 2014, 17:26
There was a thing I found out relating to the number of keys programmed to the ecu. I think it's 4 off the top of my head.
I had to clear those on mine before I could reprogramme mine.
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Nchillin75 on July 3, 2014, 18:54
Right all,

I can tell you now that thatcham obviously covered off the disconnecting of the alarm horn. And however quiet you think it is in the stock position, its ridiculously loud with your head next to it!

it also refuses to stop until you reconnect it!
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Anonymous on July 3, 2014, 19:12
It will have a battery back up to stop someone disconnecting it to shut it up if trying to steal the car
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Nchillin75 on July 3, 2014, 19:22
yes I realised that when I disconnected it

ok I've tried the pairing sequence for black and grey key / fob - nothing works. also note - replacing the fob battery makes no difference either, or blipping it in various places around the car.

Auto Electrician I think.
Title: Re: URGENT help needed ! key fob/alarm.
Post by: carolineasb on July 3, 2014, 21:57
Silly question but have you actually checked the car's battery?
Title: Re: URGENT help needed ! key fob/alarm.
Post by: onion86 on July 4, 2014, 08:32
Quote from: "carolineasb"Silly question but have you actually checked the car's battery?
I think that base is covered as the car starts fine, if there is enough power to start it then there is definitely enough for the fob to work.
Title: Re: URGENT help needed ! key fob/alarm.
Post by: carolineasb on July 4, 2014, 12:18
Just first thing that my hubby (Mechanic) said.  Electrical problems with battery and alternator can cause problems with alarm.
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Nchillin75 on July 4, 2014, 14:11
No it definitely appears to be a link between the RF fob and car. Power side of things all appears fine.  s:( :( s:(
Title: Re: URGENT help needed ! key fob/alarm.
Post by: Nchillin75 on July 5, 2014, 14:45
Right, I can tell you now this issue is either related to intense heat or solar radiation. Nice rainy day today, I thought oh I'll just see if the fob works...Both work!

Car fixed.

I will be getting an auto tech to test the system but I suspect it's an RF issue. Problem is, if you can't use a convertible in the sunshine its kinda not worth having one. Once fixed or improved I will post findings just in case anyone else has this problem.

Many thanks for all the assistance.