GMC 2003 Envoy - Manual (Page 283)

Electronically Controlled Air
Suspension System
Your v 0 hide may be t^quipped with an eiecirofiically
controlled air suspension system lhat aulomaticalty
keeps your v&hicta level as you load and unload. The
system Includes a compressor, two height sensors
and two air springs supporting The rear axle.
The syslem also has an internal dock lo prevent
overheating if the system overheats, all laveEIng function
slops until the system cools down. Duifng this time,
ihe indicator light on №e air inllator systam wHI be
Hashing.
The ignition has to be on for the system to inflate, In
order to raise thg vehicin to the standard fide height alter
loading The system can lower (he vehicle lo ihe
standard fide heighl after unloading wilh Ihe Ignition on
and also for up to 30 minutes alter the ignihon has
been turned oil,
Von may hear the compressor operating when you load
your vehicle, and poriDdically as The system adjusts
the vehicle to the standard rids
heighl.
Load leveling will net function nonnally with the inllator
hoso attached to ihe Inllator outlet. Remove ihe inflator
hose from ihe outlel during leading end unloading.
If (he vehicle is parked for an axtendeiJ period of bma,
some breed down pf the suspension is normal. Uporr
starting the vehicle, proper height will be achieved.
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