Hood airbag collision sensor

[In_a_state]

I'm in the market for a used IS300h (2015 model or such) and while researching the car a bit I became worried about the hood pop up safety system.

It seems the sensor can be triggered with ease sometimes and I would much more prefer disabling it. Can the sensor be plugged out without triggering any error or is there a way to bypass this system and not worry about any collision triggering this sensor and causing a hefty service fee?

[ColinBarber]

To answer the question, I imagine the two pressure sensors are continuously being monitored by the system and therefore disconnecting them will activate a warning (MOT failure). Probably a better way would be to disconnect the actuators, but I don't know if the system can determine if they are plugged in or not, if yes then you would also get a warning.

However I wouldn't advise touching a safety system on the vehicle. Your 'fee' would be a lot more if a pedestrian suffered head trauma and your insurance was invalidated because you have altered the vehicle and not told them.

[Brechin Slate]

4 hours ago, In_a_state said:

I'm in the market for a used IS300h (2015 model or such) and while researching the car a bit I became worried about the hood pop up safety system.

It seems the sensor can be triggered with ease sometimes and I would much more prefer disabling it. Can the sensor be plugged out without triggering any error or is there a way to bypass this system and not worry about any collision triggering this sensor and causing a hefty service fee?

This is worth a read when you have an hour or two 🙂

 

[In_a_state]

Appreciate the responses, read through the whole thread now.
I fully understand and appreciate the feature if it works as it should, however I have nudged a small parking pole in the past and "kissed" the back of another car while in traffic at minimum speed, I worry of the repair costs for such non-issue situations.

If I were to decide to suspend this feature I probably would take out the sensors and reposition them without disconnection.

Thank you.

[In_a_state]

Downloaded the manual and can add more information here if anyone is interested and unaware:

 

• The Pop Up Hood will operate when the vehicle detects an impact such as the following:  The front bumper detects a frontal impact equivalent to or greater than that of a pedestrian while the vehicle being driven within the operational speed range of approximately 25 to 55 km/h (16 to 34 mph). (The system is operated by an impact of threshold level or greater, even in the case of a minor collision that may not leave a trace on the front bumper. Also, depending on the impact conditions or vehicle speed, the system may be operated by a collision with a light or small object or a small animal.)
• In other situations the system may operate when an impact is applied to the lower part of the vehicle or front bumper, such as the following:
  • Colliding with a curb
  • Falling into a deep hole
  • Landing hard 
  • Hitting the slope of a parking lot, an undulating road, a protruding object or falling object

 

• The Pop Up Hood may not operate properly under the following conditions:
  • If a pedestrian collides with the right or left corner of the front bumper or the side of the vehicle. As such impacts may be difficult to detect, the system may not operate. 
  • If the vehicle speed is not detected correctly, such as if the vehicle is sliding sideways, the system may not operate properly.
  • Conditions under which the Pop Up Hood may not operate The Pop Up Hood may not operate in the following situations: 
  • Colliding with a lying pedestrian
  • A frontal impact applied to the front bumper while driving at speeds outside of the operational speed range
  • A side impact or rear impact
  • A vehicle rollover (In some accident situations, the Pop Up Hood may operate.)

 

• Pop Up Hood precautions
  • Make sure to close the hood before driving, as the system may not operate properly if the hood is not fully closed. 
  • Make sure that all 4 tires are of the specified size and inflated to the specified tire pressure (P. 544). If tires of a different size are used, the system may not operate properly. 
  • If something has hit the area around the front bumper, the sensors may be damaged even if the Pop Up Hood has not operated. Have the vehicle inspected by any authorized Lexus dealer or repairer, or another duly qualified and equipped professional.  
  • Do not remove or repair the parts or wiring of the Pop Up Hood, as doing so may cause accidental operation or prevent the system from operating properly. If repair or replacement is necessary, contact any authorized Lexus dealer or repairer, or another duly qualified and equipped professional. 
  • Do not remove such components as the front bumper, hood or suspension, or replace them with non-genuine parts, as doing so may prevent the system from operating properly.
  • Do not install anything to the front bumper or hood, as doing so may prevent the sensors from detecting an impact correctly and prevent the system from operating properly.
  • Do not close the hood with force or apply load to the lifters, as doing so may damage the lifters and prevent the system from operating properly.
  • Do not modify the suspension, as changes made to the vehicle height may prevent the system from operating properly

[shine668555]

 If you totally want to stop this from happening the cheapest way to do this is unplug the struts that pop the hood and replace with blank plugs and 2.7ohm resistors. Car will still think that pop up hood system is there and on collision will trigger it. (I haven't looked in a way to map the system out completely, don't think it's possible as it's a safety thing) That will leave you with a message on instrument cluster that won't go away and crash data written in SRS ecu. What you do then is take apart the centre console (under armrest and storage box) is where the SRS ECU is located and send it off to any of those companies that reflash ECUs to clear crash data (costs in region of £50). I learned this the hard way, bumped an animal and system shot the hood up, no bumper damage, but two dents on hood from struts and bent hinges. So hood and hinges can be reused, but costs more to fix dents, respray, and new struts at £700 a pair than blanking system off.

[paulrnx]

Messing around with this system will likely invalidate an insurance policy. Certainly in the UK at least. This modification would have to be declared to an insurance company and most would then decline to provide cover I think.

[Brechin Slate]

I thought long and hard about disabling mine after reading about £3k repair bills. Bottom line is, if it does activate it's almost certainly going to be the result of an accident in which case it's an insurance claim. If I did disable it and hit a pedestrian, the £3k/no insurance would be the least of my worries.  I'll leave mine alone and sleep easy.

[shine668555]

That's a good point on the insurance front, hasn't crossed my mind tbf. If you do hit a pedestrian then yes I believe that could cause problems If they find out car was coming with this specific safety feature, and they would find out as system still gets triggered with this bypass method. And as far as I've gone into electrics on Lexus/Toyota there's no easy ways of disabling/mapping out any system that car came with from factory.

[Thackeray]

I wondered about this, too, before I bought my car. It sounds like an expensive repair if you have to pay for it yourself. I did wonder if I should choose a different car because of this potential cost.

But my thinking then was that if you hit something at over 16 mph you'll almost certainly be claiming insurance anyway. And if the bonnet pops up at parking speed (it's not supposed to activate below 16 mph) that would be very annoying but maybe Lexus could be persuaded there was a fault and pay for repair if an insurance company said there was no damage to the bodywork.

But ultimately, what persuaded me was the thought that if some pedestrian stepped out in front of me without looking (it's a quiet car) and died of head injuries after hitting the bonnet and the hard metal of the engine below it, this would not be annoying like an extra cost or an insurance claim, this would be devastating. I know some people could shrug this off but I don't think I could.

The pop-up struts are designed to place a gap between the soft aluminium bonnet and the hard metal bits of engine below so that head injuries are more survivable. If I knew that this device could have saved a life and it had been disabled, I think this would be even more upsetting. A cost of £3,000 (even if I had to pay it myself) would be insignificant by comparison.

So I decided to go ahead buying the car and I haven't regretted it yet. No sign of the bonnet popping up yet, either.

[paulrnx]

I have a feeling that there is some form of requirement for all new cars to have pop up bonnets. Probably stems from the NCAP tests that all new car models go through. I don’t understand why someone would want to make this mod. It’s there for good reason. I imagine there would be a substantial liability if a pedestrian was killed or seriously injured and it was found out that the pop up bonnet had been fudged not to deploy.

[In_a_state]

Not to prolong the debate, but please look at the information from the manual that I shared o answer the question as to why someone would want to do it.

If the car is out of warranty the repair costs a good percentage of the car current value. Each owner can weigh for himself the risk chance, benefit and reward.

The requirement is to have a certain distance between the bonnet and the engine, the pop up system substitutes for that. How useful it really is could be up for debate, it only functions at certain speeds and sorts of impact.

Thank you everyone for the responses.

[Shada]

9 hours ago, In_a_state said:

Not to prolong the debate, but please look at the information from the manual that I shared o answer the question as to why someone would want to do it.

If the car is out of warranty the repair costs a good percentage of the car current value. Each owner can weigh for himself the risk chance, benefit and reward.

The requirement is to have a certain distance between the bonnet and the engine, the pop up system substitutes for that. How useful it really is could be up for debate, it only functions at certain speeds and sorts of impact.

Thank you everyone for the responses.

I disabled mine and got slated on here for it. However I've had countless pm's from people looking to do theirs. 

It involves bumper removal ect so if you want a how to then drop a pm. 

[paulrnx]

What is the incidence rate of the pop-up bonnet deploying? Surely this is very low, almost zero? Possibly take more care not bumping into things too.

[Jayw13702]

2 minutes ago, paulrnx said:

What is the incidence rate of the pop-up bonnet deploying? Surely this is very low, almost zero? Possibly take more care not bumping into things too.

im tempting fate here........

 

Ive done 120,000 miles in 2.5 years and as yet haven't triggered it.

I wouldn't say I take anymore care than I would in a car that doesn't have the system fitted, it was only when my nearly flat Battery triggered the warning a few days ago that I remembered I had the system

[Andrew888]

23 hours ago, Shada said:

I disabled mine and got slated on here for it. However I've had countless pm's from people looking to do theirs. 

It involves bumper removal ect so if you want a how to then drop a pm. 

Its quite a popular "mod" in Japan. they use plugs that terminate at the end of the harness with the resistors built in.

[paulrnx]

I can just see this happening to me now because I’ve been too blasé about it on here 😀

[HugoRibeiro]

On 1/5/2021 at 12:41 AM, shine668555 said:

 If you totally want to stop this from happening the cheapest way to do this is unplug the struts that pop the hood and replace with blank plugs and 2.7ohm resistors. Car will still think that pop up hood system is there and on collision will trigger it. (I haven't looked in a way to map the system out completely, don't think it's possible as it's a safety thing) That will leave you with a message on instrument cluster that won't go away and crash data written in SRS ecu. What you do then is take apart the centre console (under armrest and storage box) is where the SRS ECU is located and send it off to any of those companies that reflash ECUs to clear crash data (costs in region of £50). I learned this the hard way, bumped an animal and system shot the hood up, no bumper damage, but two dents on hood from struts and bent hinges. So hood and hinges can be reused, but costs more to fix dents, respray, and new struts at £700 a pair than blanking system off.

Can you please tell me more in detail how to do it? Or do you have the link to see someone solving that? 
thank you! 

[nelutzustrada]

Can you please tell me how to disable it? 

I hit a dog and now i have "Pop up hood activated".