My truck still has the airbag light on. I was told by someone here that the code it is displaying (4-6-4) is indicating a driver's side seat belt pre-tensioner problem.

Question: What can I meter or check before I go to the dealer ? I think I may have pinched a wire when I pulled my seats, so I would like to rule that out before the dealer...

Any info would be appreciated...

 

B-man,

Go out and read the codes. When the ignition is cycled (turned off and then on), the air bag indicator will remain lit for six seconds and then go out. If an SRS fault exists, the air bag indicator will then flash the two-digit LFC. The air bag indicator will flash the LFC five times, then it will remain illuminated for the rest of the key cycle. The RCM will also communicate the current and historical DTCs through the DLC, using a scan tool. If the air bag indicator does not function, and the system detects a fault condition, the RCM will signal the GEM to activate an audible chime. The chime is a series of five sets of five tone bursts. If the chime is heard, the SRS and the air bag indicator require repair.

LFCs are prioritized. If two or more faults occur at the same time, the fault having the highest priority will be displayed first. After that fault has been corrected, the next highest priority fault will be displayed.

Let us know what you get.

Regards

Jean Marc Chartier

 

JMC -

Thanks for the reply.

I never get the chime, just the 4 flashes, 6 flashes repeated over and over until it finally stays lit.

Someone once posted that that was the code for the driver's side belt pre-tensioner. I was trying to figure out a way to use a DMM to check for a wiring fault, but am unsure as to where I should be checking.

Any info would be greatly appreciated...

B-Man

PS. Jeepers, where did you get your knowledge of the SRS system ??

 

B-Man,

Info is from the Shop manuals. BTW, what vehicle are we talking about?

JMC

 

JMC -

Sorry, I forgot to post my sig.

2001 SuperCrew XLT, 5.4L, 3.55 LS, 4R70W, Towing Package

Thanks again...

 

B-Man,

A code 46 is for the driver side pretensioner circuit open or low resistance. A scan tool should show the Body code 1877 or 1885 depending on which one it is. I do not have the applicable charts for the F-150 to help with the testing. When you removed your seat(s) did you disconnect the battery? If not disconnect it and leave it for at least 1 minute so the back up power supply for the SRS gets depleted. Reconnect it and test again for codes.

JMC

 

Disconnect the battery and then disconnect the pretensioner connector.. Check the resistance of the pretensioner.
It should be within 1.7 - 3.2 ohms.
If it's higher or lower, then you need a new pretensioner.
If not, then I would carry it to a pro who has all the diagnostic support..

Good Luck!!

FordMasterTech

 

FordMasterTech -

Thanks for the reply. Could you elaborate as to where I will find the connector you are talking about ?

Thanks again...

 

Underneath the driver's seat..
2 wire connector
Light green with a red stripe wire &
Light green with a black stripe wire.

Good Luck!

FordMasterTech

 

Also be sure to disconnect and test the wires toward the seat from the connector and not towards the floorpan, otherwise you would get a false reading.

FordMasterTech

 

Thanks !!

I'll post the results after I meter it tomorrow...

 

FordMasterTech -

I just ran out and looked and the only connector I see has 2 wires, a solid black and a brown with a white trace. Is the connector you reference a different connector than the one that goes to the seat belt in the driver's seat itself?

I could be off on the colors - it's dark and I'm getting to be an old ba$tard (almost 40) so my eyes aren't exactly what they once were, you know?

Thanks yet again - I owe you a beer or two, huh ??

 

I may be wrong on the colors, but follow the 2 pin connector that you see. If it goes to the seatbelt pretensioner, then forgive me for being dependent upon a screwed up wiring diagram.
Once you locate the 2 wires going to the pretensioner, check the resistance while the connector is disconnected.

Good Luck!!
Keep me posted

FordMasterTech

 

Pardon my ignorance, but what exactly does the pre-tensioner look like?

The wire I found looks like it goes to the buckle part of the seat belt (the side closest to the center console / seat).

Again, thanks for your patience and knowledge...

 

B-Man,

From the manual; Safety Belt Buckle and Pretensioner Assembly —Front

The driver and front outboard passenger safety belt buckle and pretensioner are secured to the front seat cushion frame assembly. This allows the front safety belt buckle end to move with the front seat.

The belt and buckle assembly pretensioner is a pyrotechnic device that removes excess webbing from the safety belt system. The belt and buckle assembly pretensioner uses the same crash sensor system as the air bag supplemental restraint system (SRS). When the belt and buckle assembly pretensioner deploys, the buckle moves downward, pulling excess webbing from the lap and shoulder safety belts.