Airbag Light

[V8Rumble]

Hi

I have recently bought a 99 plate LS400 WITH 109K on the clock and am loving every minute.

I had the cambelt and water pump changed today at an independant garage but unfortunately the Battery went flat as the boot was open(need to buy a new battery).

Once it was charged up and the car started all was okay but we noticed the airbag light was on and then flashing on and off.

Has anyone got any pointers as to why this might have happened as both of the garages fault scanners do not list Lexus.

Any help most welcome

[steve2006]

Hello and welcome to the LOC.

This can happen when the Battery is disconnected ( the "Check VSC" light may also appear on the dash display).

The system usually resets itself after the car has been driven for a while so the ABS light should then go off.

Regarding OBDII code readers there have been problems with communications on the LS400 so not all will successfully work.

There is another way of obtaining fault codes by shorting out the Tc and E1 connections in the diagnostic socket and reading the TCCS code on the dash display which can then be converted to OBDII codes.

[V8Rumble]

Thanks for the very informative reply I don't suppose there is "how to" on how to short the pins or a diagram of the pin layout. I will have a search a bit later when I have a bit more time.

Many thanks again.

[Ruud]

Tim,

See below picture.

The left socket is under the bonnet, the right one is the Diagnostic port underneath driver's side dash.

I used the one under the bonnet - easier access.

[V8Rumble]

Thanks for the pinout diagram Ruud I will have a look when I get time

Sunnybrae if I get it sorted I will let you know

[V8Rumble]

Quick update

I shorted the pins on the under bonnet socket but only got a couple of messages up and none of then faults so I tried disconnecting the Battery again but to no avail I still have the flashing airbag light.

[V8Rumble]

The messages were;

Cruise

VSC ok

EFI NG then E

I will try the under dash socket

[V8Rumble]

Could I be so bold as to ask how much they charged for the service.

PM me if you would rather not disclose on a public forum

[alien1974]

wont be cheap a new airbag

[V8Rumble]

OK thanks for the reply

[Malc]

..... Lexus labour rates are usually, I thought, about £150 an hour so maybe the fee is totally concessionary to you at this time ......... kind hearted Lexus dealers that they are !!!

Malc

[V8Rumble]

Afraid I cannot help on how to immobilise the airbag circuit to work on it but maybe try to pick the brains of the local mechanics as I doubt the system will be different to most if not all makes of cars.

An update on my light is that last Friday the guy that did the cambelt and water pump plugged his Snap on diagnostic tool into the car but this time told it that it was a 3.0l Camry and it connected.

The fault came up as passenger airbag so he cleared the fault as he considered it to be an old fault that came back when the power went off a sort of ghost fault.

So far so good as the light has not come back on and he re scanned it and it shows no fault present.

Obviously this would not be any good if it was an engine fault unless they use the same software but I would say the Camry is probably two cylinders short of a proper engine lol, correct me if I am wrong.

[alien1974]

hopefully that sorted it, as its the first time i have heard of an airbag fault on these

[cruisermark]

Afraid I cannot help on how to immobilise the airbag circuit to work on it but maybe try to pick the brains of the local mechanics as I doubt the system will be different to most if not all makes of cars.

An update on my light is that last Friday the guy that did the cambelt and water pump plugged his Snap on diagnostic tool into the car but this time told it that it was a 3.0l Camry and it connected.

The fault came up as passenger airbag so he cleared the fault as he considered it to be an old fault that came back when the power went off a sort of ghost fault.

So far so good as the light has not come back on and he re scanned it and it shows no fault present.

Obviously this would not be any good if it was an engine fault unless they use the same software but I would say the Camry is probably two cylinders short of a proper engine lol, correct me if I am wrong.

That's good news, I've decided to bite the bullet and pay the £420.00!

really!

have you not got a local auto electrician who could try doing the same as the tim - it might solve your problem and alot cheaply. - i have never heard of an airbag light problem either

[V8Rumble]

Good luck hope you get it sorted cheaply

[steve2006]

One of the things often overlooked when the ABS warning light suddenly illuminates is the wiring under the driver's seat.

You take the car to your local mechanic who is a good deal shorter than yourself, finding he cannot reach the pedals in comfort the 1st thing he does is move the seat forward.

The last time that seat was probably moved was when the car was bought so things like plugs/sockets and wiring under there may be a little brittle and the seat movement has now broken something.

Always worth checking under the seat before doing anything else.

[Titch LS]

The airbag light problem could be a duff sensor playing up. Unexplained weird faults can sometimes be due to failing ECU capacitors or even a weak Battery.

[ROYT]

Before I spent £420 I would try the one on eBay less than £15, worth a gamble

The unit is located in front if the gear lever and plugs in.

Turn ignition key to lock position.

Disconnect the Battery and wait a minute before starting work

When I had this problem with mine [after removing most of the dashboard etc for another reason]

the ABS light was on.

I put in a second hand unit [Ebay] and the light was still on.

I read about a sequence of alternatively earthing Tc terminal and AB terminal twice in 1 second cycles, finally keeping the earth to Tc.

This worked after a couple of tries and the second hand airbag unit is still in [several years later]

My '94 may not be the same but I would check before spending £400+, if you replace it and there is a fault the light will still be on.