A malfunction with the air suspension system has been detected
Start with the basics and check the switch in the right front passenger footwell , by
the kick panel and see if the air suspension service switch has been turned off , or
perhaps its fuse # 12 ( 15 amp ) for the air suspension switch , or fuse # 15 - 5 amp
for the air suspension module ( but unless you have noticed other things not working
it's probably not that fuse ) In the power distribution box in the engine compartment
( Ford states to disconnect your battery before servicing anything in the PD BOX )
fuse # 109 is a 50 amp maxi-fuse for the air suspension compressor , or it could be
a sensor or the compressor itself etc.
If all of this does not work. CALL STRUTMASTERS - they have conversion kits to do away with the air system all together. IT really helped my out and I did not have to keep guessing what or when the next air part would fail on me.
Give them a call. It saved me money and time. Now I get to enjoy my ride.
Check your owners manual. If you don't have one copy & paste this link. http://www.genuineservice.com/genuineservice/en/gloveboxresults
For this answer you will need to either use an OBD code reader or go to a shop that can read codes. Also make sure that your air suspension switch is turned on.
Check battery connections, check alternator out put. Exc.
On a 2001 Ford Expedition : The GAS TANK SIZES in U.S. gallons are : Standard suspension ( 26 ) Rear air suspension and 4x4 ( 30 )
You can use a code reader or disconect your battery for about ten minutes.
light sensor
Check bulbs - they are double filamented with the smaller being for stop lights Check for a blown fuse Check the operation of the stop light switch
2 wheel drive with standard suspension ( 26 gallons ) 2 wheel drive and 4X4 with rear air suspension ( 30 gallons )
30 U.S. gallons with the rear air suspension ( 26 U.S. gallons for 2 wheel drive / standard suspension )
Check fuses
Check Kelleys Blue Book for prices.
Check Kelleys Blue Book for prices.