05 WH intermitant tyre presure & air bag faults

[krankieone]

In the last week the left rear tyre presure intermitantly has no reading (service tyre preasure displayed on dash warning light flashes and alarm sounds) and the air bag warning light comes on & off .

I'm thinking possibly loose/dirty conection or similar .

Has anyone had similar problems and what was the solution?

Secondly how does the tyre presure sensor system work what powers the sensor and how is the signal transmited to the "pick-up" and where are these located?

I am much more comfortable weilding a spanner than a multimeter and would really appreciate someone pointing me in the right direction thanks.

[hotqld]

On the air bag warning lights I had this on and off for 12 months.
From memory to clear that code you need to disconnect the battery.

Do you have a code reader to point you in the right direction like Auto enginuity?....$600.00 ex USA

In my case the code it tripped was saying the front row seat restraints so I checked all the plugs and sockets under the drivers and passengers seat.
Then went on utube and found a vid to test the seat belt pretensioners were good electrically.
This fixed it for 4 months. and back on again!

Then Clarkie here suggested check all fuses in the control modules under the bonnet.
So I disconnected the battery and took every fuse out cleaned and put the multimeter across the fuse....I replaced a couple that showed resistance.
Then I swapped all the relays around, cleaning the terminals.
Reconnected the battery and no air bag light for the past 6-10 months.

Any working on the air bag system I use to disconnect the battery ...I did not like the thought of accidently setting off the air bags, apparently they go off with a big bang.

[krankieone]

I dont have a code reader (more of a carbie & points guy being dragged into the 21 centuary) might try the fuse box sounds simple & logical thanks for a starting point

[Clarky]

Some sort of code reader is a must these days, you can muddle your way through but my experience is you spend more on unnecessary parts that would cover the cost of a basic reader.
This is supposed to read WH codes http://www.ebay.com.au/itm/Superchip...item46173ebf4b

The tyre monitoring system has 3 pickup sensors, front left & right in the inner guards & one rear up near the spare.

The airbag fuses are the ones in the yellow cradle, rear fuse box under the bonnet.

[krankieone]

thanks for the reply Clarky

I am still curious how the signal is sent from the wheel to the pick-up does the sensor have a battery or similar?

[Clarky]

The sensors do have a battery in them & eventually they will need replacing, they go to sleep after a 20min period of inactivity (when parked) to preserve battery life.
They are a sealed item but some here have had success braking into them & replacing the battery.
Mine are 8 years old & one off them is indicating poor performance on a diagnostic scan. I want to try the after market rubber stemmed ones because I have snapped the metal ones off in the bush.

If you need to replace one (or all) make sure you get the 433mhz ones, the American version are 315mhz & don't work on the WH.

[krankieone]

Thanks Clarky I'll try swapping it with the spare and see if the dodgy one comes good and try to sourse a new one .