A couple weeks ago my cluster airbag warning light turned on. I didn't realize it at first, but my passenger airbag switch's light blew out, thus setting off the cluster warning light. Now many folks will say it's the clockspring when the cluster light goes on, but mine has never been wet and my horn and cruise control work flawlessly, so I figured I should look elsewhere first. After a little searching and posting, I was lead to the passenger airbag switch as a possible source of the cluster warning light. Thanks go to Jonny Jeep for providing this information from his 03 FSM body supplement:
faulty switch will trigger the airbag lamp in the cluster, resistances found too...
The ACM continuously monitors the resistance of the Passenger Airbag On - Off Switch circuits to identify the switch position and to provide switch circuit diagnostics.
* ON Position: Passenger Airbag On - Off Switch resistance = 175 to 190 ohms
* OFF Position: Passenger Airbag On - Off Switch resistance = 820 to 870 ohms
If the ACM detects that the PAB On - Off Switch circuits are open, shorted to ground, or shorted to battery voltage, it will set Active and Stored DTC’s. When a DTC is detected by the ACM, it will transmit a PCI bus message to the Instrument Cluster to illuminate the Airbag warning indicator.
passenger airbag switch contacts 3 and 6 should be used to measure the resistance. they are the ones that the light green/orange and yellow/light green wires go to.
Alright, so I measure the resistance and all is normal, so the switch portion is fine. Then I start thinking about what happened when the cluster light came on. The passenger airbag switch light flickered a bit, then went out. So I check the bulb's continuity and find out it's blown. Well, an entire switch assembly is around $35-$40 online (plus shipping), so I figure that's not too bad to replace, but why even pay that when I'm still troubleshooting and I'm not even sure that little light working or not will set off the cluster airbag warning light (it does BTW, that's what this little story and write-up is about).
So after spending $1.50 at Radioshack (part # 272-1141) and a few minutes with a soldering gun, I now have not only fixed my passenger airbag switch light, but in turn have turned off the cluster warning light. You will need to strip away the wire insulation on this particular bulb. Radioshack had another bulb without insulation, but it was not in stock at the time and the salesman said it was really tiny compared to the bulb it was replacing. The bulb I used and indicated above is physically the same size as the bulb it is replacing. Not sure of all the voltage/wattage specs of the stock bulb, but the new one seems to be working fine.
[EDIT: RS part # 272-1154 works too and does not require stripping wires - this is what I used the 2nd time]
1) Wedge your fingers under the edge of the console (picture #1)
2) Press the little tab forward on each side (picture #2)
3) Picture #3 shows how the back of the switch has tabs that slip under the console. So you just release the front 2 tabs and slip it rearward.
4) Slide down the red plug lock, and disconnect the switch (picture #4)
5) Unscrew the 3 screws (picture #5) This picture also shows the pins you use for the resistance testing in case the entire switch is bad and not just the bulb.
6) Take a small flat screwdriver and gently pry each side a bit to release the tabs and pull the 2 main halves apart. (picture #6) The green circuit board will slide upwards out of the plastic shell making it easier to work on.
7) Picture #7 shows the two halves, and the two small spots where you'll need to desolder the existing bulb and solder in the new bulb.
8) Reassemble and enjoy a fixed passenger airbag switch light and reset cluster airbag warning light (checks automatically, no need to do anything but turn the key)
I hope this helps. I know it's a bit verbose, but I wanted to provide troubleshooting information along with the fix.