Chevrolet/GMC 3.0L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-13336148) - 2020 - CRC - 9/5/19
Instruments and Controls
11
Emissions Inspection and
Maintenance Programs
If the vehicle requires an Emissions
Inspection/Maintenance test, the
test equipment will likely connect to
the vehicle's Data Link
Connector (DLC).
The DLC is under the instrument
panel to the left of the steering
wheel. Connecting devices that are
not used to perform an Emissions
Inspection/Maintenance test or to
service the vehicle may affect
vehicle operation. See
“
Add-On
Electrical Equipment
”
in the owner
’
s
manual. See your dealer if
assistance is needed.
The vehicle may not pass
inspection if:
.
The light is on when the engine
is running.
.
The light does not come on
when the ignition is on with the
engine not running.
.
Critical emission control systems
have not been completely
diagnosed. If this happens, the
vehicle would not be ready for
inspection and might require
several days of routine driving
before the system is ready for
inspection. This can happen if
the 12-volt battery has recently
been replaced or run down, or if
the vehicle has recently been
serviced.
See your dealer if the vehicle will
not pass or cannot be made ready
for the test.
Wait-to-Start Light
This light comes on briefly while
starting the engine, as a check to
show the light is working.
If the wait-to-start light comes on,
the glow plug system is required
and operating. Wait until the light
turns off before starting the engine.
This light may not come on in warm
temperatures.
See
.