Here is a possible fix for a flashing airbag code 27. The problem was on a 2000 Ranger (out of warranty of course) , but should apply to Explorer and other Ford trucks as well.

Problem: After ignition switch turned on, airbag lamp on dash flashed code 27 several times, then remained lit.
Explanation of code: Fault in PAD (passenger airbag disconnect) warning lamp circuit.
Most probable cause: Burned out light bulb in PAD unit

Pinpoint tests were found in Ranger forum, a non-specific fix was posted in the F150 forum. Poster in F150 stated that bulb was not available from Ford, but you could buy the whole unit for $70. Not sure about you all but a $70 light bulb sounded rather steep to me.

Items required: Source is Radio Shack
1. RS part # 276-351 5MM Yellow LED 2.1 Volt 20 MA (2 in package)$2.49
2. RS part # 271-1325 2.2K ohm resistor (5 pack) $.99

Procedure:
1. Remove the PAD switch housing cover plate by prying it downward and popping it off.
2. Remove 3 sheet metal screws holding PAD housing to dash, unit should drop down.
3. Remove electrical connector from PAD unit by pressing release tang on top side and pull connector out.
Remove 2 screws holding PAD unit to housing, and remove
4. Using a small screwdriver, pry the top of the PAD unit cover off. Start at the backside next to where the wire connector inserts. Be careful not to break plastic retainers.
5. Remove the circuit board from the PAD key housing (Just lift it up)
6.Using a voltmeter set on 10X Ohms scale, measure across the lamp leads. If no deflection of meter is seen, lamp is open (burned out.
If meter moves, then a fault in the wiring is indicated.
7. Using a small pencil soldering iron, remove the lamp from the circuit board.
8. Holding the circuit board so as to orient the components up and wiring connector away from your body, solder in one of the LED's.
The LED should have 1 lead longer than the other, place the longer lead to your left and solder it in place.
9. Flip the circuit board over to expose the wiring path side.
10. Using an exacto knife or other cutting instrument, cut a hole in(open up) the wiring path between the outermost LED wire and wiring connector.
11. Solder one of the resistors across the just opened up wiring path.

If you did all this right, you can plug the board into harness and test by turning the key on. The LED should light momentarily during the airbag test sequence, then extinguish. Codes should not flash on the dash lamp. If all this is OK, then reassemble all parts, and you just saved yourself 70 bucks.

If the LED does not light, double check that you got the polarity of the LED correct.

Thanks to all on the Ranger forum and F150 forum for the help.

Shame on Ford for the sloppy engineering (or intentional gouging) as the case may be.

Dialtone