Malfunction Indicator Lamp; Engine Light); Service Vehicle Soon Light; Brake System Warning Light - Chevrolet 4500 HD 2023 Manual

54 Instruments and Controls
If the light stays on, or comes on while
driving, there may be a problem with the
electrical charging system (such as a loose
or broken fan belt). Pull off to a safe place
well clear of traffic and perform the check
and corrective action. Driving while this light
is on could drain the battery.
Check and Corrective Action
1. Check to see if the fan belt is broken or
loose.
2. If the fan belt is loose, adjust the
tension.
3. If the fan belt is broken or there is no
abnormality in the fan belt, see your
dealer for service.
See Battery - North America 0 261, Jump
Starting - North America 0 297, and Engine
Drive Belt Routing 0 346.

Malfunction Indicator Lamp

(Check Engine Light)
This light should come on to show that it is
working when the engine control switch is
turned to the ON position, and then should
go out after the engine is started.
If this light stays on or comes on while the
engine is running, it indicates a malfunction
with the engine electronic emission control
system. Avoid driving at high speeds and
have the vehicle inspected by your dealer.
If this light comes on when the fuel tank is
empty, you do not need to have your
vehicle serviced. See Running Out of Fuel
0 231.
If this light comes on intermittently or
continuously while driving, service is
required. Even if the vehicle is drivable and
does not require towing, see your dealer as
soon as possible. Continued driving without
having the system serviced could cause
damage to the emission control system.
It could also affect fuel economy and
drivability.

Service Vehicle Soon Light

This light comes on briefly when the engine
control switch is in the ON position, but the
engine is not running, as a check to show
the light is working. It should go out when
the engine is started.
If the light stays on, or comes on while
driving, the vehicle control system may be
malfunctioning. Take the vehicle to your
dealer for service as soon as possible.

Brake System Warning Light

(Parking Brake Light)
This light should come on briefly when the
engine control switch is turned to the ON
position, and then should go out after the
engine is started.