Jamieat

Ok guys, maybe someone can help me out with this airbag light code 25.

The code is for "DTC B1871 - Pass Air Bag Deactivation (PAD) Switch Fault."

From what I've read, there is no physical deactivation switch so to speak for the passenger side like in the previous model fords where you could use the key on the dash to turn it on and off.

I've read that the "passenger airbag light" above the radio can cause this fault if the connection or bulb is blown breaking the circuit or if a connector under the seat is loose or not seated.

However, the "passenger airbag light" above the radio is working as it should and proves out when the key it turned on each time and will also illuminate if a light object is placed in the passenger seat or light pressure applied and will turn off when pressure is removed.

This also indicates to me that the passenger pressure sensor in the seat is functioning correctly as well.

I've taken apart all the connections and sprayed with contact cleaner and exercised the connection before seating again to ensure the contact is good.

With that said, I'm still getting this code and I'd like to know what I can to do trouble shoot it further. Just seems odd to me that everything (that I'm aware of at least) associated with this code seems to be functioning properly.

Any advice or potential components to investigate would be greatly appreciated!

Thanks !

Jamieat

Does anyone have a clue about this issue or has experienced it in the past?

BadFish523

Does the airbag light on the dash come on at startup? If so then you should be ok there. The deactivation switch I believe is tied into the passenger seat. It reads the pressure when someone sits on the seat and is over a specified weight. Sorry i cant give you too many details.

Jamieat

Yes, as stated in the initial post, the passenger airbag light above the radio comes on at start up, then proves out once the initialization sequence is complete.

I know the pressure sensor is also working due to the fact that I can place light pressure on the seat and the passenger airbag light will come on indicating that the pressure switch has been triggered and the passenger airbag is disabled due to the light weight (like a small child is in the seat).

I've cleaned all the connections and the seat belt pretensioner. Not sure what to do next.

Thanks for the feed back either way!

Jamieat

This must really be an uncommon issue. I would have bet that someone had experienced this code before and it be something other than the light.

I may replace the bulb anyway, perhaps it has gotten old and is not drawing the correct voltage? Dont know what else to try.

Jamieat

I'm bumping this post simply due to the fact that I'm in hopes that someone with any knowledge about this issue may come along and see it and offer up some advice.

My apologies if that annoys anyone!

If anyone has any suggestions or thoughts on what I may be able to trouble shoot or a bypass method for this (PAD) for trouble shooting purposes, I'm open to ideas at this point.

Jojodapyro

Pinpoint Test D: LFC 25/DTC B1871 — Passenger Air Bag Deactivation (PAD) Switch Fault

Normal Operation
The restraints control module (RCM) monitors the status of the passenger air bag deactivation (PAD) switch at pin C2041-8, circuit 1112 (W/LB). The PAD switch signals the RCM by switching a resistance to ground. If the RCM senses 900-1100 ohms in the PAD switch, it enables the passenger air bag and turns off the PAD switch warning lamp. If the RCM senses 400-600 ohms in the PAD switch, it deactivates the passenger air bag and turns the PAD switch warning lamp on. If the RCM detects an invalid resistance, it will store a diagnostic trouble code (DTC) B1871 in memory and flash a lamp fault code (LFC)

Possible Causes
A PAD switch fault could be caused by:
*a damaged or inoperative PAD switch.
*a damaged or inoperative RCM module.
*a short to battery, short to ground or open on circuit 1112 (W/LB).

This is what I have found.
Along with:

http://www.troublecodes.net/bcodes/b1871/

Jamieat

Only problem is everything seems to be functioning properly. The pressure switch cuts the airbag off if my kid gets in the seat and it'll cut back on when she gets out.

Light above radio proves out each time I start the truck like it's supposed to.
I will investigate the circuit to see if I have any connections or any other issues. I'm lost at this point and just want the light off! Thanks for the feedback.

01-7700

Hello, Did you get this sorted out? I have just developed the same problem on my truck, well it behaves the same way. Thanks.

Jamieat

No, I never did. I need to try and trace it down at some point tho. I believe it's a wiring issue.