Air Bag Light Is Permanently On

Duncan Roberts · June 25, 2013

Seems a little suspicion hangs over the car, unusual selection of issues.

ColinBarber · June 25, 2013

the sensor does not appear to be there. I'm beginning to wonder what has been done to this car!

it is a little lower down on the 400h. You will see it below the number plate. This is the sensor for the AC system.

Air intake for the engine is part of the MAF sensor within the engine bay after the air filter.

Do you have a photo of your rear view mirror? This is a unit above it which attaches to the windscreen, this houses the auto wiper sensor and also the connection to the mirror itself comes from there for the auto dipping feature.

gogsck · June 25, 2013

Hi, I have attached a picture of the gap where the sensor behind the mirror should be.

Still can't find external temperature sensor. I will attach a picture of the lower bumper when my phone charges up enough for flash!

ColinBarber · June 25, 2013

yes you are missing the sensor and the back cover. There also should be wiring which comes from that unit into the back of the mirror. I assume your mirror doesn't work (green LED on?).

Is any of the wiring there? If not hopefully it has just been pushed up into the lining.

steve2006 · June 25, 2013

That's over £200.00 worth of missing electronic gizmo!

gogsck · June 25, 2013

The wiring goes to the mirror and The mirror does light up green and switch on and off. There is a piece of plastic lying in the boot which I will look to see if it fits behind the mirror but no sensor.

gogsck · June 25, 2013

Here is a picture of under the number plate. As you can see there is no sensor. Do you happen have a picture of what it should look like?

ColinBarber · June 26, 2013

gogsck · June 26, 2013

Hi thanks for that. The sensor is clearly missing from my car.

You can get an OEM version in the States for $25 but I cant find one in the UK. looks like I may have to go to Lexus.

I am currently trying to find the best software for reading & resetting the airbag light. There are some on eBay, one of which looks good as it says you can reprogram keys and immobilizers too - so I could program a second key.

I will have to look for the auto windsreenwiper sensor too.

Believe it or not the car is getting sorted bit by bit and is a great car to drive!

Thanks for everyone's help. it is very much appreciated.

ColinBarber · June 26, 2013

if you have a master key you can program extra keys without a computer / scan tool.

Did you try resetting the airbag light by first connecting the pins before turning on the ignition? Maybe an airbag sensor is missing as well.

gogsck · June 26, 2013

Yes I have a master key. How do I program another key?

Couldn't get the airbag to reset or even get a code using pins 4 & 13 but thought that diagnostic software would point me in the correct direction.

I have downloaded a full service manual and electrical manual so if I can find the codes I should be able to sort the problem.

ColinBarber · June 26, 2013

you may have to search about for the procedure. here is one for older vehicles but I'm not sure it works for newer models.

http://www.lexusownersclub.co.uk/forum/topic/9509-rx-300-master-key-setup/

gogsck · June 26, 2013

Hi Colin, I had read that it is not possible to program a key for a UK 2007 400h without software but will give it a try. Have to get a key of eBay first though. You don't know what the model number on the sticker on the remote should say do you as mine has fallen off / been lost / removed!

DanD · June 28, 2013

How can you be sure that there is not a genuine problem with your airbag?

I had a similar problem with a Mitsubishi some years ago and diagnostics showed that there was a problem with an internal spring that had snapped...

gogsck · July 4, 2013

Managed to get a rain sensor and ambient temperature sensor. The rain sensor is now fitted but I need to find a plug to fit the temperature sensor as that has been chopped off.

I have also got a copy of Toyota Techstream so will now try to diagnose the airbag issue.

billygarrett · July 12, 2013

you could try your software. They don't always work for non-engine related error codes but give it a try.

Otherwise you need to obtain and then clear the error codes:

Reading:

switch on the ignition and wait around 1 minute

connect pins 4 and 13 together and the warning light will flash out a code. Normally two digits so if you get 1 flash, pause and then 3 flashes it is error code 13. If there is more than 1 error there will be a longer pause between error codes and it then repeats.

This will give you the current code(s). If you connect the two pins together and then turn on the ignition it should provide any previous stored error codes.

Clearing:

Once you have read the codes, disconnect the pins and then the warning light should come on within 5 seconds.

After the light has come on, connect the pins together again within 2 to 4 seconds.

The light will go out and within 2 to 4 seconds disconnect the pins.

The light will come on and within 2 to 4 seconds connect the pins.

The light should go off after 4 seconds and then blink no errors (on / off twice per second)

you can then disconnect and turn off ignition. This may need to be repeated a couple of times to get it right.

I also found some of this procedure on another thread when the ABS warning & Check VSC error came up.

It is here: http://www.toyotanation.com/forum/63-toyota-highlander-hybrid/341699-how-reset-check-engine-vsc-warning-lights.html#post5089282

It works!!

So For future use, I bought an OBD2 plug from eBay for about £3 +p&P and connected those pins to each other via a push button ltable lamp type of switch which I stuck inside the pug with a hot glue gun!!!

So I tried it out and the diagnostic menu came up on the satnav screen showing no faults of course sinc i had cleared them previously!! BRILL!

Now there is no need to grope under the steering wheel with bits of wire!!!!

The other piece of kt that got me out of trouble is a Scan Gauge from http://www.scangauge.com/. I only had it 2 weeks and a VSC error came up while I was miles from home. The Scangauge cleared it!!! BRILL

Please keep these tips and codes coming!!!

A list of codes would be good!

Many thanks.

gogsck · July 13, 2013

Still no joy with the Airbag light. The Toyota Techstream software does cover the airbag but no error codes show.

I did discover that I had a DIAG VSC 45 error which I cleared using the instructions in your link - pressing brake pedal 8 times.

Duncan Roberts · July 14, 2013

Still no joy with the Airbag light. The Toyota Techstream software does cover the airbag but no error codes show.

I did discover that I had a DIAG VSC 45 error which I cleared using the instructions in your link - pressing brake pedal 8 times.

Perhaps there IS something wrong with the air bag and the light is merely doing its job.... Tis car has had a few 'odd' faults such as pieces missing so this might be another problem.

ColinBarber · July 14, 2013

I did discover that I had a DIAG VSC 45 error which I cleared using the instructions in your link - pressing brake pedal 8 times.

you can get that sometimes when changing brake pads, needs to be cleared once and should't come back again unless there actually is a problem.

gogsck · July 14, 2013

Hi Duncan. I realise the light may be / is doing its job but I need to diagnose why the light is on and fix it.<br />I recon the DIAG VSC 45 was probably due to brake pads.<br />I am trying to turn a not too good car into a good car and appreciate everyone's help to do so - thanks. Still need to try and find why the Airbag light is on but no error codes to point me in the correct direction!

Sandi · February 24, 2020

My son was bouncing back and forth in the passenger seat of my Lexus RX350 2010, then the "Check SRS System Airbag" light came on? Could a wire have come lose? How can I fix it without having to go to the dealer? Please help me. Thanks for your help in advance.