Airbag and seatbelt warning lights on, codes U1088 and U1000

[Harpo]

Hi all

Now i really need some help.

I have a problem to pass inspection due to my airbag warning light is on now and then.

I have some time ago removed the passenger airbag and replaced it with a airbag simulator, basically a resistor to fool the computer.

That has worked well for over a year, but i have had some issues with flaky connection at the simulator due to the thin wires to the airbag.

When the connection is lost at the airbag sim i always got the message "service airbag system".

Now i have fixed that flaky connection some time ago and it has worked well.

Before and after i fixed it i experienced some strange flashing from the warning lights, both airbag and seatbelt lights.
First both lights will come on, after a while the seatbelt light is starting to flash for a quite long time and then go out. But the airbag lamp stays lit.

There is NO info on the DIC about "service airbag system"

This happens on every startup or ign on. There is quite a difference in how long time that will pass before this happens tough.

Sometimes right away, and sometimes it will be ok for 10 or 15 minutes before it comes on.


I went to a shop today to get it scanned for codes and we found two.

With ign on we found U1088 "lost SIR/SDM communication". With the engine running a second code appears together with the first and it is U1000 "class2 data link malfunction"


Whats going on, where should i start looking.

 

[The_Roadie]

Any intelligent module or the data comm wiring between them, can kill the data bus and cause those errors. It's why the designers brought all the data comm wires together into two "splice packs" to make it possible to troubleshoot them bu disconnecting one module off the shared bus at a time. I'd search for that phrase here and at trailvoy (I've discussed the issue before), and make sure your mechanic understands the concept of data comm splice packs.

You should also check on all the grounds in the vehicle, because they can be an issue if they're flaky.
Location of electrical grounds - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

 

[Harpo]

Thank you Roadiewan Offroadie

I do have searched a little and i have seen some threads over at TV.

As i am a die hard DIY i hate to leave my vehicles to anyone else, but i realize my limitations(auto transmissions and complex electronics), but is there anything i could do myself
except checking the ground connections?.
I understand that i should check the connections under the seats as it appears that many faults can come from there, is it anything else i can do before i have to leave it to a professional?.

Is there a chance that the instrument cluster have something to do with this, i think he found the codes i was mentioning under the instrument cluster section in his scanner tool.
I asked him if he had a Tech2 instrument(he didn't use that) and he has, but he said that he doesn't have the right card for my truck or something. Would i be able to see more info if using a Tech2 instrument to narrow down the search area or doesn't it matter?.

I have noticed a faint flicker on the display at the far right side in the DIC if that might have anything to do with a bad connection or corrosion on the circuit board that i have seen could cause problems.

This shop i was at today is a small independent shop and as almost always they who has a advanced scanner also have a hard time using them correctly as it seems they never are computer geeks in any way. They have the scanners because they have to, but never have the real interest to learn how to use them properly unfortunately.

I am trying to get this fixed myself, and if i have to leave it to a professional, so be it. But it will be my last resort.


Thanks
Janne

 

[Harpo]

Hi

Im having trouble with my airbag lamp.
Today i tried out a new to me software Scan XL.

When i try to read out some trouble codes before my airbag lamp is on, i get this.


B0013 Passenger knee bolster deployment control (sub fault)

B0017 Passenger frontal deployment loop open

B1000 ECU malfunction


This is what i can get before the airbag lamp sets, if i try when the airbag lamp is on i get nothing.


Is there someone that can explain to me what the heck this means, we dont have any "knee bolster" airbags that i am sure of.
Frontal deployment loop is open???!!

This is should i add stored codes, but there is no way to clear them. I tried, and with a loud rattle from the pcm or some relays i never heard before i tried to clear them three times, but they always comes back again.


I really want to have my airbags functional but i cant afford to let the dealer do it, that will cost a fortune, $200 just to connect the tech2 and then at least $180 /hour and parts

For now i have done a dirty bypass and desoldered my airbag led and connected the led to the abs led just to pass inspection.

Thanks for any help and advice.

 

[Sparky]

Seatbelt light? There's a seatbelt light? I've never seen one (which I always thought was odd)

 

[Harpo]

yeah there is, check your driver seat beltbuckle wires.
Its easy to do.

And there is a chime as well
if everything works properly.