Jeep Gladiator 2021 Owner's Manual page 140

138 GETTING TO KNOW YOUR INSTRUMENT PANEL
3. Approximately 15 seconds later, one of two
things will happen:
The MIL will flash for about 10 seconds

and then return to being fully illuminated
until you turn OFF the ignition or start the
engine. This means that your vehicle's
OBD II system is not ready and you
should not proceed to the I/M station.
The MIL will not flash at all and will

remain fully illuminated until you place
the ignition in the off position or start the
engine. This means that your vehicle's
OBD II system is ready and you can
proceed to the I/M station.
If your OBD II system is not ready, you should
see an authorized dealer or repair facility. If your
vehicle was recently serviced or had a battery
failure or replacement, you may need to do
nothing more than drive your vehicle as you
normally would in order for your OBD II system
to update. A recheck with the above test routine
may then indicate that the system is now ready.
Regardless of whether your vehicle's OBD II
system is ready, if the MIL is illuminated during
normal vehicle operation you should have your
vehicle serviced before going to the I/M station.
The I/M station can fail your vehicle because
the MIL is on with the engine running.