Diagnostics
OnStar Vehicle Diagnostics will
perform a vehicle check every
month. It will check the engine,
transmission, antilock brakes, and
major vehicle systems. It also
checks the tire pressures, if the
vehicle is equipped with the Tire
Pressure Monitoring System. If a
diagnostics check is needed
between e-mails, push 
, and
an Advisor can run a check.
See also:
Hill Start Assist (HSA)
This vehicle has a Hill Start Assist (HSA) feature, which may be useful when
the vehicle is stopped on a grade. This feature is designed to prevent the
vehicle from rolling, either forward or rearwa ...
Rear Safety Belt Comfort Guides
This vehicle may have rear shoulder belt comfort guides for the outboard
passenger positions in the rear seat. If not, they are available through your
dealer. The guides may provide added safety bel ...
Powertrain
The XLR's Northstar V-8 VVT is a 90-degree, DOHC, four-valves-per-cylinder
engine featuring an aluminum block and cylinder heads, and a valvetrain
configuration with roller finger followers. The e ...