Air bag problems

[NormanE]

Hi

I've a 2003 Yaris 1.0

The air bags lights are on with fault codes B1100 & B0133

I've had the  wiring between the seat belt pre tensioner and ECU repaired and I've had the clock spring squib replaced

When trying to erase the fault codes the light goes out for a split second and then comes back on. Faults show as current and as history.

Any ideas where I should try next ? This seems to be a bigger problem than I first anticipated

[flash22]

I would think it's a bad pre tensioner, centre airbag if the wiring checks out and pin fitment is ok its possibly a air bag issue

 

If the car has been in an accident (drivers airbag and seatbelt tensioner is the giveaway) the srs (airbag ecu) may need to be reset (aka crash data)

[NormanE]

Thanks for the reply Flash22

I've an update, I tried clearing the DTC using a SST check wire. It was unsuccessful but i did get the flashing seat belt light codes of 31 and 62. So far I'v not been able to find out what these mean.

The car hasn't been in an accident where the airbags have deployed, but it was hit whilst stationary in a car park. this has displaced the front valance.

Would this impact be sufficient to trigger the fault codes do you think ?

If the SRS Module needs reset is this a DIY task do you know ? If so can you advise where is it located and how easy it is to access ? Would the front crash sensor need to be replaced also ?

Sorry to be a pain but any light you can shed is greatly appreciated 

[flash22]

the srs ecu is under the centre console iirc (Edit. its behind the centre kick panel under the dash - passenger side) , the reset is not a diy job you usually have to send it off, a shock may have been detected as a crash

62 - Drivers seatbelt pre tensioner (short to live)

31 - malfunction of SRS control unit (srs ecu)

 

So if the wiring checks, ok the tensioner has gone bad or gone off, if you unplug the tensioner does the code change ?

[flash22]

You could get a used air bag ecu of ebay/breakers, just make sure its the same part number

[NormanE]

Thanks. I'm trying to source a second hand ecu that hasn't been involved in a crash

Are there any connectors in between the ecu and the pretensioner do you know ? I couldnt see any but the wiring is all buried.

Would it be safe to take the plug out of the pretensioner and then reconnect the Battery to recheck the code? Seems to me that it would generate a code if it was unplugged?

[flash22]

Battery disconnected for 30 mins then disconnect the pre tensioner

you could try a resistor across the plug (removed from the tensioner) to fool the ecu - do this at your own risk tho !! 2.7-3.0 ohm at 1/4w or 1/2w

[NormanE]

Sorry, I'm being a little thick here.

So I disconnect the pretensioner and then reconnect the Battery to check if the codes have changed ?

I havent the equipment to put a resistor across the terminals. But I presume if the system is armed and the pretensioner is unplugged it would generate a fault code anyway?

If so I miss the point of disconnecting the pretensioner?

 

[flash22]

Yes it should throw a different code as it's an open circuit - if it changes code the tensioner is at fault if it doesn't you still have a wiring fault

 

its just another way of testing without a multimeter