Air Bag Light Is Permanently On

gogsck · June 20, 2013

My Air bag light is on, in my 2007 RX 400h SE-L.

Is there a way to reset this without going to the dealers? They are 70 miles away.

The car had a dud 12v Battery when I bought the car and it kept going dead. It has now been changed. Could this have caused the problem?

ColinBarber · June 21, 2013

Yes that potentially could have incorrectly set an error code.

Try disconnecting the Battery -ve terminal for 60 seconds.

If that doesn't fix it there is quite a complex method to reset it.

gogsck · June 21, 2013

Disconnecting the Battery didn't fix it. What's plan B?

I do have ELM327 software and connector but I have never used it. could that reset the light or is there another way?

ColinBarber · June 21, 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.

gogsck · June 21, 2013

thanks for that. I will try it when I can get a chance. the car is outside and the forecast is rain!!!

gogsck · June 22, 2013

My ELM327 software only deals with engine codes as you said so that didn't help me.

Unfortunately connecting pins 4 & 13 didn't work either. At the point where I should get the error code the Airbag light just flashes on and off continuously at about 2 flashes per second and when I disconnect the pins the light comes on instantly. I have tried several times with no success. :(

ColinBarber · June 22, 2013

did you try first with the ignition on or off before connecting the pins?

If the ignition was on then it means there is no current error. Turn off the ignition and connect the pins and then turn on, it should give you the stored error code.

gogsck · June 23, 2013

I have tried with the ignition off and on before starting the procedure but I can only get a steady flashing airbag light. you mentioned no current. could there be a blown fuse?

steve2006 · June 23, 2013

By any chance have the front seats been moved recently?

gogsck · June 23, 2013

The seats have been adjusted using the power adjuster on the side of the seats. I just bought this car last Monday so anything could have been done in the past.

It has one or two issues that need sorting and the airbag light is one of the most urgent ones.

The external temperature gauge is not showing a reading either. I am wondering if it might be missing!

Duncan Roberts · June 24, 2013

The seats have been adjusted using the power adjuster on the side of the seats. I just bought this car last Monday so anything could have been done in the past.

It has one or two issues that need sorting and the airbag light is one of the most urgent ones.

The external temperature gauge is not showing a reading either. I am wondering if it might be missing!

Presumably you bought it from a private vendor with the faults not a dealer?

gogsck · June 24, 2013

Yes. I took a chance as I got it very very cheap but missed the Airbag light!! :(

I have fixed a few other issues and the car looks great but I need to find a solution for the airbag and external temperature sensor.

Duncan Roberts · June 24, 2013

Yes. I took a chance as I got it very very cheap but missed the Airbag light!! :(

I have fixed a few other issues and the car looks great but I need to find a solution for the airbag and external temperature sensor.

The perhaps spend a little of your saving on going to a dealer. You might also be advised to have him inspect it as it does seem to have an unusual number of irritating faults which is far from normal with these cars.

DanD · June 24, 2013

I would also suggest that you take it to a dealer. The airbag could be related to a genuine fault that needs sorting out.

Others will confirm I'm sure... I do not think there is any chance of the airbag going off when it is not meant to, but on the other hand it may not deploy when you want/need it to.

gogsck · June 24, 2013

I understand the importance of the airbag working properly but as a qualified computer engineer / electronics engineer and long time fixer of cars, I thought (and hoped) there would be a way to fix things myself!

I tend to trust things that I have fixed better than those that have been fixed by someone else.

steve2006 · June 24, 2013

An OBDII code read may provide some clues as to the Airbag problem.

The reason I enquired about the seats being moved is there are connectors under the seat which form part of the Airbag or SRS as it is refered to which may have become dislodged when the seat(s) were adjusted after probably being left in the same position for years by the previous owner.

There is also wiring to the seat belt pretensioning system under the seats which is also part of the SRS.

It doesn't take long to have a look under them for anything obvious but if you do see anything amiss please follow the correct proceedures for working on the SRS system don't just plug something straight back in.

As for the Outside temperature sensor they are mounted at the front of the car behind the lower bumper area more or less behind where the top right hand corner of the number plate is. A common cause of an incorrect reading is that the mounting bracket has broken allowing the sensor to drop down and give false readings or the wiring/connections to it has/have deteriorated due to water ingress.

gogsck · June 24, 2013

Thanks for that. I will check under the seats. There are a lot of connectors as the DVD player is mounted under the drivers seat.

I saw a picture on line of a RX350 showing the temperature sensor attached to one of the vertical bits on the lower bumper and visible externally but it is not present on mine. Is it hidden on the RX 400h?

steve2006 · June 24, 2013

Bottom picture shows sensor location.

gogsck · June 24, 2013

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

Duncan Roberts · June 24, 2013

_{To better judge the car, how much/little did you pay for it and how many miles has it done?}

gogsck · June 24, 2013

Hi I paid £8,500 in an auction and it has done 55,000 miles. The bodywork looks great. There is one absolutely tiny shopping trolley dent but other than that if looks perfect. I think it is worth sorting it out as it also drives perfectly.

gogsck · June 24, 2013

I am needing to find someone that is breaking one to get the missing parts. I suspect that the front bumper has been changed and some bits not refitted. i.e. headlight washers and external temperature sensor. There is something missing from the windscreen just behind the rear view mirror which I think is the auto windscreen sensor too. but everything else works fine.

Shepherd · June 25, 2013

OK no RX experience but here it was happened to my car an IS. First the air bag light cam on intermediately and then went off then after some time it came back constantly. So after trying a lot of things, including sticking a 3 ohm resistor in the airbag leads under the front seat I finally bought a Toyota VCI cable from eBay. This VCI cable cost about £25 and came with pirated Toyota laptop software that is used by the dealers. It only works on windows XP. it got a a code that the front knee airbag was faulty. so looked it up, and the connector was a little loose. pushed it in and its all fine now and the light hasn't come back in about six months . This is known problem in IS and it has cost some people about $2000 in the states where they rip out the dash board and change the whole knee airbag harness.

I found that most of the airbag leads are yellow and the connectors are quite chunk so easy to identify.

steve2006 · June 25, 2013

Sounds a little suspicious with a possible front bumper and windscreen parts missing like it's previously been in an accident, repaired but not reported if there is no remark on the front of the V5C.

Check the MOT history on the VOSA website and see if they all run consecutively or if there is a gap where the car may have been taken off the road for a while.

gogsck · June 25, 2013

Hi it is recorded as stolen & recovered in 2010 but DVLA check & MOTs shows all mileages consistent. looks like windscreen may have been replaced as it is the only one not to say Lexus on it but that could have been due to a stone chip.