Ram Trucks 2015 ProMaster Commercial - Owner Manual - Manual (Page 136)

Operation of the Brake Warning Light can be checked by
turning the ignition switch from the OFF position to the
ON/RUN position. The light should illuminate for ap-
proximately two seconds. The light should then turn off
unless the parking brake is applied or a brake fault is
detected. If the light does not illuminate, have the light
inspected by an authorized dealer.
The light also will turn on when the parking brake is
applied with the ignition switch in the ON/RUN position.
NOTE:
This light shows only that the parking brake is
applied. It does not show the degree of brake application.
16. Malfunction Indicator Light (MIL)
The Malfunction Indicator Light (MIL) is part
of an onboard diagnostic (OBDII) system
which monitors the emissions and engine con-
trol system. If the vehicle is ready for emissions
testing, the light will come on when the ignition is first
turned on and remain on, as a bulb check, until the
engine is started. If the vehicle is not ready for emissions
testing, the light will come on when the ignition is first
turned on and remain on for 15 seconds, then blink for
five seconds, and remain on until the vehicle is started. If
the bulb does not come on during starting, have the
condition investigated promptly.
If this light comes on and remains on while driving, it
suggests a potential engine control problem and the need
for system service.
Although your vehicle will usually be drivable and not
need towing, see your authorized dealer for service as
soon as possible.
134 UNDERSTANDING YOUR INSTRUMENT PANEL