Wait-To-Start Light - Chevrolet GMC Duramax 2023 Manual

Caution (Continued)
lead to costly repairs not covered by the
vehicle warranty. This could also affect
the vehicle s ability to pass an Emissions
Inspection/Maintenance test. See
Accessories and Modifications 0 45.
When the light is on, a malfunction has
been detected. Diagnosis and service may be
required.
Poor fuel quality can cause inefficient engine
operation and poor driveability, which may
go away once the engine is warmed up.
If this occurs, change the fuel brand. It may
require at least one full tank of the proper
fuel to turn the light off. See Fuel for Diesel
Engines 0 23.
If the light remains on, see your dealer.
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
Instruments and Controls
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.
The fast warm-up glow plug system makes
the wait-to-start light stay on for a shorter
amount of time than most diesel engines.
See Starting the Diesel Engine 0 10.
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