IS250 - After installing new battery alarm wont stop

Linas.P · December 4, 2020

So I got a call from the guy who got my old IS250. The Battery was dead on the car for over 6 months and now he got new Battery (Bosch S4 as you suppose to) and as soon as Battery is connected alarm goes off (both siren, horn and back-up siren). Car has factory alarm+immobiliser and no electrical modifications.

My initial answer was simply use the key fob to unlock the car so that alarm stops. Does not work. Then I said - try closing the doors and everything, lock the car and unlock. Still does not work.

My final idea was that maybe fob Battery is dead as well, so I said try touching the fob to the start button to turn of immobiliser. I got there and we tried it together - does not work either.

Basically, car locks and unlocks with key fob as it suppose to be, you can start the engine, shut-it off, lock the car, unlock the car but alarm won't stop. So now I am kind of out of ideas and it is extremely embarrassing as well when you doing it at 10:30PM 😅

Any suggestions?

JDM-Fiend · December 4, 2020

7 minutes ago, Linas.P said:

So I got a call from the guy who got my old IS250. The battery was dead on the car for over 6 months and now he got new battery (Bosch S4 as you suppose to) and as soon as battery is connected alarm goes off (both siren, horn and back-up siren). Car has factory alarm+immobiliser and no electrical modifications.

My initial answer was simply use the key fob to unlock the car so that alarm stops. Does not work. Then I said - try closing the doors and everything, lock the car and unlock. Still does not work.

My final idea was that maybe fob battery is dead as well, so I said try touching the fob to the start button to turn of immobiliser. I got there and we tried it together - does not work either.

Basically, car locks and unlocks with key fob as it suppose to be, you can start the engine, shut-it off, lock the car, unlock the car but alarm won't stop. So now I am kind of out of ideas and it is extremely embarrassing as well when you doing it at 10:30PM 😅

Any suggestions?

I had a similar problem on a different car (Honda Civic), ended being an issue with a sensor on the bonnet so I ended up disconnecting that sensor.

Sorry I can't help much more than that!

Also, perhaps locking the car with the key instead of using the fob may bypass the alarm.

chr15gb · December 5, 2020

Worth a punt:

Possible Solution

Get out of the vehicle.
Lock the car with the key fob or lock the driver’s door with the key.
Leave the vehicle parked for at least 5 minutes.
Press unlock on the keyfob to unlock the car. Don’t open any doors yet.
Remove the emergency key from the key fob and lock/unlock the driver’s door three times.
Now enter the vehicle and start the engine. If your car has Start/Stop button, press the button with your keyfob, not your finger.

https://www.youcanic.com/guide/lexus-wont-start-after-replacing-disconnecting-battery

Herbie · December 5, 2020

If the alarm has a backup Battery it could be that this is flat too and needs charging or replacing. Just a guess.

Linas.P · December 5, 2020

I will tray tomorrow... as waiting for 5 minutes is rather difficult when car horn is beeping continuously.

To be honest that is the only solutions I have found myself - i.e. combination of locking and unlocking car doors, with key, or the fob. User guide does not say anything either. The reason for the alarm is quite simple - it was armed when Battery gone dead. The door was unlocked with the key, meaning this is intrusion and the Battery was disconnected - so there are like 3 different reasons for it to be angry.

However, what guide suggest is simply to close all the doors, lock and unlock the car and that should be it, but I have done it already. As during the day we not going to be so bothered to wake up all street I will try to repeat all steps few times and maybe it will calm down.

Beamish · December 5, 2020

Close all doors and bonnet and lock with the fob.

Use the emergency key to unlock the driver's door and hopefully it will stop.

Dec.

chr15gb · December 5, 2020

I read the unlock/ lock three times using the blade key in the door somewhere else too. Said it is the immobiliser reset procedure, albeit it was on a much older Toyota.

Linas.P · December 6, 2020

Thanks all, it solved now. My plan was to lock everything before connecting negative terminal, then just shut the bonnet and try using key fob to lock and unlock car until it calms down. That didn't work.

Eventually, I got inside of the car and with everything closed started the engine and alarm stopped.... that is - until I opened the door to get out and it started again... but then simply locking and unlocking it with fob whilst sitting inside with everything closed turned off the alarm for good.

In the end of the day, I cannot confirm that any particular sequence works, so be prepared to listen to alarm for a while. What seems to help in general - having everything closed and trying to turn on the engine as soon as possible for immobiliser to get recognised. After that it seems that fob starts working properly and not only locking/unlocking the doors, but as well turns alarm on and off.

The morale of the story - if you planning to keep the car of the road for a while, then make sure you don't have alarm on, disconnect negative terminal and then just lock the car with the key. As well don't leave too much petrol in the tank. Mine had ~1/4th of the tank and petrol was already off, good that I was expecting it and brought 5L canister of 98 Octane + Redex Petrol system cleaner and octane booster. On old petrol car would start for few second, splatter a bit and stall, but after adding fresh petrol it ran perfectly fine. I would as well advise burning all old petrol before attempting MOT as surely it won't burn very cleanly.

Besides - how to know if you thread is till above legal limit ? Well... if such worms live in the main channel then they are good to go 😅

MartinH · December 28, 2020

"I have this problem too"

Linas.P · December 30, 2020

I think in current circumstances this will be common issue 😁

The best solution is as always preventative, if you not driving the car often - unlock the car, lock all the doors except of drivers, remove the Battery, then lock the driver door with key. Store battery in warm dry place.

Otherwise - be prepared to listen for alarm for 5 minutes and ideally don't do it late at night as neighbours won't appreciate it.

MartinH · December 30, 2020

I solved it no problem — I called the RAC. Their guy was here within half an hour, car started immediately. He did not like the Battery, which wasn't charging up nicely. (His battery/charging assessment tool, apparently an £1800 cost, fell over twice and had to be rebooted...by removing its Battery!) I suggested a new Bosch item (readily available at £75) but no, not the thing. Varta was the prescription, a mere £137.50 at Eurospares. So there we are. All good.

Texas · December 31, 2020

So pray tell why not the Bosch?

MartinH · December 31, 2020

RAC tech said they had experienced a number of failures

Linas.P · January 2, 2021

Seems like up-sold you for what they wanted to sell. But Vatra is not bad Battery, just don't feel it is worth £50 extra over Bosch, hardly even the same price. The failures on Bosch batteries are not common either + they have 4 years warranty, so should be solved by that (in my case I just didn't have receipt).

What is important to note: acid batteries are fundamentally outdated technology, they should not be "cycled" and should never run flat, even getting acid Battery discharged once can damage it, keeping it dead for a while will almost definitely damage it. So can Bosch S4 die because it got flat and was left flat for a week - absolutely... any acid Battery will do the same and this is not specifically issue with Bosch, it is an issue with the Battery technology itself.

Anyway, I am sure what matters is that car is alive now!

Tyre Tread · January 2, 2021

On 12/30/2020 at 3:34 PM, Linas.P said:

I think in current circumstances this will be common issue 😁

The best solution is as always preventative, if you not driving the car often - unlock the car, lock all the doors except of drivers, remove the battery, then lock the driver door with key. Store battery in warm dry place.

Otherwise - be prepared to listen for alarm for 5 minutes and ideally don't do it late at night as neighbours won't appreciate it.

Or, better still, leave the Battery on the car and put it on an intelligent charger (e.g. Optimate) as I do with both of my cars that use up Battery while standing.

MartinH · January 2, 2021

1 hour ago, Tyre Tread said:

Or, better still, leave the battery on the car and put it on an intelligent charger (e.g. Optimate) as I do with both of my cars that use up battery while standing.

Chance would be a fine thing! Living in inner London, we don't have the option of attaching the car to a power source, because we don't have the option of parking off-street. Indeed, it's often a question of how many streets away will we have to park!

MartinH · January 2, 2021

2 hours ago, Linas.P said:

Anyway, I am sure what matters is that car is alive now!

Yes indeedy Linas, I am in cost so far stepp'd in, that should I wade no more, returning were as tedious as go o'er — as Macbeth might have said.

Linas.P · January 2, 2021

2 hours ago, Tyre Tread said:

Or, better still, leave the battery on the car and put it on an intelligent charger (e.g. Optimate) as I do with both of my cars that use up battery while standing.

Yeah same as Martin said - this is great solution, but implies you should have private garage or at least very cozy driveway... not something wast majority of population has.

Texas · January 3, 2021

Sounds like an absolute nightmare!

Tyre Tread · January 11, 2021

On 1/2/2021 at 7:55 PM, MartinH said:

Chance would be a fine thing! Living in inner London, we don't have the option of attaching the car to a power source, because we don't have the option of parking off-street. Indeed, it's often a question of how many streets away will we have to park!

Ah London. I've heard of it but vowed never to g to such a place.

MartinH · January 11, 2021

13 hours ago, Tyre Tread said:

Ah London. I've heard of it but vowed never to g to such a place.

I went to Cardiff when I lived in Swansea – disagreed with it.

Tyre Tread · January 11, 2021

1 hour ago, MartinH said:

I went to Cardiff when I lived in Swansea – disagreed with it.

Ah, Swansea. Worked there for a while. Didn't like it much. Lots of money about and self entitled people.

MartinH · January 11, 2021

44 minutes ago, Tyre Tread said:

Ah, Swansea. Worked there for a while. Didn't like it much. Lots of money about and self entitled people.

Everyone got puffed up with their swelling property values right?

BlaccBird · December 24, 2023

07 IS250

Changed the Battery and car won’t start at all. No sounds or clicking. Just lights up when the button is pushed for the Acc and dies when you try to start it. Fob won’t lock the car but unlocks the car… weird thing.. trunk won’t open, screen doesn’t turn on at all. Checked all fuses and no issues there and there’s adequate power flowing through vehicle but won’t budge. I’m just frustrated at this point. Never had this issue until I tried to change the Battery. Any help is much appreciated.

Linas.P · December 24, 2023

Did anything unusual happened during the change? like sparks of smoke coming out from anywhere?

Jokes aside, there could be many things. Starting from basics - are you sure it is correct Battery, correctly connected and it has at least 12V? I assume you fitted new Battery, but even new things are sometimes faulty. Could you try connecting old Battery if it works at all? Simple logic here - what was changed is the Battery, so it is now important to eliminate the Battery as the cause of issue.

Other related question - why did you change the Battery? Maybe it wasn't the Battery issue to begin with? Anyway I am sure more information is needed before the question can be answered, at the moment it is speculation at best.

P.S. It would be best to start new thread, because to be fair you issue is not related to the issue I had and you will get better responses without confusing them.