Throwing Some Codes. help if you can

so my airbag light came on the other day. i noticed it when i got back from a trip. my truck had been used by my parents for a week or so then in went into a body shop for repair work all while i was gone. i noticed it when i got back.

i got it checked out and it was showing 3 codes.
B1660 - Passenger seat airbag active mode indicator malfunction
B1900 - Short in pretensioner squib (right) circuit
B1901 - Open in pretensioner squib (right) circuit

any help is apprecitaed.

 

bumpp

 

Look under the passenger seat, and make sure everything is plugged in. The pre-tensioner is in the seat belt, so make sure that's plugged in, as well.

Nice thing about diagnosing SRS stguff, the system self checks every few seconds, so you'll know right away if you found the problem or not. If you just had body work done, you might wanna take it back to the shop, and have them fix it.

 

thanks. except the body work was completed a day before i moved, so im sol unless i wanna drive another 6000km

 

Can you describe what body work was done?

 

I have a B1901 code myself. I always thought it was the seat pressure sensor that went bad, might just be the seat belt pre tensioner by itself. I'm going to check that out further and see what is what. For future owners purposes I'll try to report back. Having your airbags become an intermittent feature, not so good.

 

Also if anyone has any link/info/suggestions on a complete wiring diagram for the truck. I have a Haynes repair manual but it doesn't say boo about airbag wiring. I know it's all yellow - I just want to know which is which and what starts/ends where so I can trace the wiring down completely from the seat belt tensioner all the way to the main airbag computer. Thanks!

 

The airbag module is underneath the center console if I remember correctly, there’s not much wiring to trace around.

 

Yeah I think I know where the module is. I just want to be able to trace back the wiring from there to wherever the pretensioner squib is. I assume that is the charge that locks up the seat belt... that sound about right?

The only confusing thing is that sometimes I can get my code to clear if I have a large enough person in that seat. Makes me think its the pressure sensor.

 

Actually I'm thinking that the moments where I had someone in the passenger seat and having the code go away may have been coincidental.

The code the fancy reader shot me was:

B1901 OPEN INP/T SQUIB (D SEAT SIDE) CIRCUIT

After re reading that, kind of seems like I have the good old clockspring broken/replacement need. I notice the 09s had this problem a bit. Does that sound right? Or is there a way to further confirm that diagnosis?

I only have the B1901 code. No others.

 

In your case it will either be the airbag ecu, the harness or your seat belt. To diagnose it you can disconnect the connector of the driver side seat belt. Take a very thin wire or paper clip and connect both pins of the driver side seat belt connector together and see if you get a short code for the same circuit. If you do you know the harness and ecu are good because it can now interoperate there is a short and you can confirm that the open circuit is in the pre-tensioner.

Just be careful not to force the wire/paper clip into the connector the female pins, they are small and you can damage them by stretching them then you'll never have a good connection.

 

That's the best advice I've gotten so far! Thank you so much for the detail. Before I do it I'll have to check and make sure I have the right part. I don't own the scantool, I had to go to my mechanics place for that. Ill have to see if I can rent one from my local autoparts guys. Unfortunately regular scantools dont pull the airbag codes, gotta get the big boy expensive one.

 

No problem. Just make sure your not testing the buckle, U want to pull the drivers side front and rear door sills and the 'b' pillar to get access to the pre-tensioner/seat belt.
Also whatever you do, Do not apply power to the connector or check for resistance. That can actually cause air bags to deploy.

Here is a link where someone pulled it out. But it shows the connector u want to use for your test.
https://www.tacomaworld.com/threads/seat-belt-pretensioner-repair-final-update-must-read.650694/

I typically will use t-pin when i do these test, you can grab them from officemax or staples for usually $4 for a pack of 100. Stick one in each hole and pinch the tips together works great!

 

That's huge man thank you! Basically it's just the little looks like a 2 pin connector that attaches to the seat belt reel assembly. Pull battery, short connector, plug in battery/start and check code. Then shut down, pull battery, reassemble it all and report back in here I suppose! Either I need a new airbag ECU or just the hose reel assembly since I assume the airbag part isn't a modular and replaceable part.

Also just to double check I'll get a baseline code read and make sure there aren't other codes popping. Before doing any of the above.