I have a 1997 Ford Expedition, 5.4L engine and have an air bag error code 5-2, 5 blinks followed by two blinks, repeated twice and then the air bag light stays on.

Just prior to getting this error, the battery went dead on my wife. I'm not sure the cause of that, but I jump started the vehicle and put the battery on a 2 amp charge when we got it home. Since then, no battery problems, just the air bag light.

I know the code means something, I just don't know what it is. Any help from those that know would be very much appreciated.

 

This is the 1997 LFC chart for the F150, I cannot say for sure, if it is the same for the '97 EXPY

 

All LFCs above 49 are historical versions of the corresponding code 40 lower. Have your battery tested; remove, clean, & tighten all the terminals on the 2 heavy battery wires.

 

Is there any truth to the 256 key thing-a-ma-jigger? Meaning the error code will go away after 256 executions of the key.

 

Only if you believe the 1997 factory workshop manual that says:

Personally, I haven't tried it.

 

Give it a try, and post back here. I know a few members have asked, but nobody with the LFC will try it, and let the others know.

 

It works!! It took a couple of months, but I finally must have hit the magical 256th key cycle. The air bag flashing 5-2 finally went away. Patience is a virtue.

Tuffy

 

Patience is a virtue, that is saint like, Mother Teresa would have given up already.

Thanks for letting us know it really does work.

 

And there's no way to clear this code sooner? What in the heck was FoMoCo thinking when they designed this?

- Jack

 

This is along the same lines of if you have a DTC and fix it, after 2 drive cycles it will reset itself.

If someone had access to an IDS ( the WDS replacement ) the airbag code could be reset after the repair.

 

I can understand that, Steve, but 256 key cycles? Wow! Someone really wanted to make certain things were OK, didn't they?

- Jack

 

Doesn't the number 256 seem familiar? It's one byte (2^8) of binary data.

"There are 10 kinds of people in the world: those who understand binary, and those who don't."

 

Not quite, Steve. There are 256 possible combinations of 1 and 0 bit values in a byte (8 bits). A byte is simply those 8 bits or two hex nibbles. I taught programming in several different high-level languages, assembly languages, and digital microprocessor design for 20 years, 256 was a VERY familiar number. I simply expected something smaller like 16, 8, or even 2.

But, I enjoyed your quote up there. Wonder how many people don't get it?

- Jack

 

OK, but I didn't know you were that edumacated, and I was trying to keep it simple for the peanut gallery. 256 is still all the counts in that register until it hits 11111111, so my statement is still accurate.

 

Now THAT statement was OK! Why in the heck did they decide to fill the register? It's just as easy to check the four low order bits - XOR the register with 0F and check the status flag, or, the three low order bits with 07, or.... (you get the idea).

No harm, no foul.

- Jack