2001 F150 crew cab lariat with single stage pretensioners driver's/passenger someone decided to drive down the wrong side of the road and hit me at a semi slow speed. Due to the angle it set off both airbags and bent a frame horn. I had a previous post about keeping it or letting insurance take it. With an offer of $1,095 I decided to keep it. Question on the SRS Modules if anyone knows.

Are these tied to the pcm with the vin number? IE they need to be programmed by the dealer upon install? I don't think so, see below.

How does the crash sensor in these work? There are no sensors in the bumpers/body on these models. Is the sensor a 1 time use thing?

Anyone know about part number cross compatibility with these? 1L3A-14B321-BC vs 1L3A-14B321-BD vs 1L3Z-14B321-BA ALL with the LARGE B on the cover.

I installed airbags and a driver's seat belt from the junk yard along with a used SRS Module 1L3A-14B321-BD (large B on it). The SRS Module was pulled from another 01 Crew Cab without the airbags deployed/seat belts locked up, and the airbags part number matched from an 01 expedition. The module appeared to function correctly giving me a code showing the passenger seat belt pretensioner had fired. I was driving alone in the truck during the wreck and was unaware it was also fired off.

I don't know how the crash sensor works to determine if a used model or "rebuilt" mine will function correctly and fire the airbags in a crash. (looking at some of the trucks in the salvage yard, they don't seem to work that well to begin with ha). Obviously mine, part number 1L3A-14B321-BC (Large B on it) has recorded the crash data. I can send it off to one of those airbag repair people, along with the seatbelts, but have found another online that is New old Stock as well as picked on up from a junkyard. Problem is the part numbers are different. The NOS is 1L3A-14B321-BD (Large B) same as the used SRS module I did a test run with from the junkyard.

I received the following from a vendor on ebay with the NOS -BD (Large B) module.

"Using the Mitchell Guide with your Vin.
1 Possible ECU for after 8-7-2000
1L3Z-14B321-BA
With the other used listings of 2001 F150s
showing your same part numbers, with the
Mitchell Guide showing this part number
from 8-7-2000 and the same B on all the
Cases
1L3Z-14B321-BA , 1L3Z-14B321-BD,
1L3A-14B321-BD will cross with your BC part
number"

Sorry long post, tia!

 

follow up with info found elsewhere for anyone in the future who stumbles across this post.

airbag deployment sensor is an inertia sensor that, per a ford service manual i came across online, only fires when the truck is hit from the front with "longitudinal force". The module will not fire off the airbags for hits from the side or rear. This explains the trucks I saw in the salvage yard.

Also, through much research, the rcm (restraint control modules) appear to be plug and play not requiring any vin marrying or programming. There are however specific models that relate to single/ext cab vs the crew cabs. I've seen a few places say some rcm models don't work with the single stage seat belts, however I don't see this so far as an option with crew cabs in the salvage yard. going to check on this further shortly.

To test functionality of the rcm module, one needs to simply hook everything up and power up the system. An airbag code will flash on the dash if there are any issues giving you a way to identify the problem area. I verified this feature when I used the -BD module from the salvage yard.

Only question left to verify is the 1L3Z-14B321-BA vs 1L3A-14B321-BC/BD compatibility, specifically with the single stage seatbelts.

I did find on a mustang forum that the part number family is the 14B321 designation for the rcm for expeditions/f150/some mustangs. Research on single/ext cab units show a large letter A instead of a B on the box as well as a diff part number. My plan is to pull a rcm out of crew cabs at the salvage yard and compare the part number to the single stage seatbelts. those with -BD and single stage will verify compatibility among rcm modules.

 

made my way to a salvage yard and pulled 4 crew cabs apart. everyone with pretensioner seat belts, agreeing with the ebay graphic above, from 08/00 on had the rcm ending in -BD. the one crew cab without pretensioners had an rcm with YL3A-14B321-BB and a build date of 06/00. This verified part compatibility to me between -BC and -BD.

I picked up a used unfired pretensioner seatbelt just to test my theory for $11. Hooked it all up and the srs system powered up with no faults or airbag explosions! Now i'll be getting my original seat belts rebuilt and the new old stock rcm module. Only thing left is to bend the frame back in shape.

So summary:

Airbags are plug and play.
RCM (restraint control module) 1L3A-14B321-BC and ""-BD are cross compatible. Most likely ""-BA is as well.
While 14B321 is the airbag rcm family part number, it appears 1L3A is the pretensioner family with the BC and BD as part generations.
There is no vin programing to the RCM for the SRS system to work.
The RCM module grounds through the bolts so make sure they're in good before turning the system on.
The rcm has a built in inertia switch which will only fire if the vehicle is hit from the front. airbags will not fire from side or rear hits.
Once the RCM has fired off the airbags it needs to be rebuilt or replaced. Unknown on how well inertia switch will work second go around or if it is replaced in the rebuilding process.