Black plate (18,1)Cadillac Escalade EXT Owner Manual - 20125-18 Instruments and Controls. The OBD II (On-BoardDiagnostics) system determinesthat critical emission controlsystems have not beencompletely diagnosed. Thevehicle would be considered notready for inspection. This canhappen if the 12-volt battery hasrecently been replaced or rundown. The diagnostic system isdesigned to evaluate criticalemission control systems duringnormal driving. This can takeseveral days of routine driving.If this has been done and thevehicle still does not pass theinspection for lack of OBD IIsystem readiness, your dealercan prepare the vehicle forinspection.Brake System WarningLightWith the ignition on, the brakesystem warning light comes onwhen the parking brake is set. If thevehicle is driven with the parkingbrake engaged, a chime soundswhen the vehicle speed is greaterthan 5 km/h (3 mph).The vehicle brake system consistsof two hydraulic circuits. If onecircuit is not working, the remainingcircuit can still work to stop thevehicle. For normal brakingperformance, both circuits need tobe working.If the warning light comes on and achime sounds there could be abrake problem. Have the brakesystem inspected by your dealer.This light can also come on due tolow brake fluid. See Brake Fluid onpage 10‑25 for more information.Metric EnglishThis light comes on briefly when theignition is turned to ON/RUN. If itdoes not, have it fixed so it will beready to warn if there is a problem.If the light comes on while driving,pull off the road and stop carefully.The pedal could be harder to pushor could go closer to the floor. It cantake longer to stop. If the light is stillon, have the vehicle towed forservice. See Towing the Vehicle onpage 10‑80.