Jeep Wrangler: WARNING LIGHTS AND MESSAGES / Yellow Indicator Lights

Tire Pressure Monitoring System (TPMS) Warning Light

The warning light switches on and a message is displayed to indicate that the tire pressure is lower than the recommended value and/or that slow pressure loss is occurring...

4WD Indicator Light — If Equipped

This light alerts the driver that the vehicle is in the four-wheel drive mode, and the front and rear driveshafts are mechanically locked together forcing the front and rear wheels to rotate at the same speed...

Other information:

Jeep Wrangler 2018-2026 Owners Manual: EMISSIONS INSPECTION AND MAINTENANCE PROGRAMS

In some localities, it may be a legal requirement to pass an inspection of your vehicle's emissions control system. Failure to pass could prevent vehicle registration. For states that require an Inspection and Maintenance (I/M), this check verifies the Malfunction Indicator Light (MIL) is functioning and is not on when the engine is running, and that the OBD II system is ready for testing...

Jeep Wrangler 2018-2026 Owners Manual: Additional Maintenance — B6 To B20 Biodiesel

NOTE: Under no circumstances should oil change intervals exceed 8,000 miles (12,875 km) or six months, whichever comes first when using biodiesel blends greater than 5% (B5). The owner is required to monitor mileage for B6-B20 biodiesel, the automatic oil change indicator system does not reflect the use of biofuels...