Jeep Wrangler 2018 User Manual page 82

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 sys-
tem is now ready.
Regardless of whether your vehicle's OBD II
system is ready or not, if the MIL is illumi-
nated during normal vehicle operation you
should have your vehicle serviced before go-
ing to the I/M station. The I/M station can fail
your vehicle because the MIL is on with the
engine running.
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