If the service engine soon indicator remainson, have your vehicle serviced at the firstavailable opportunity. Although somemalfunctions detected by the OBD-II may nothave symptoms that are apparent, continueddriving with the service engine soon indicatoron can result in increased emissions, lowerfuel economy, reduced engine andtransmission smoothness and lead to morecostly repairs.
Readiness for Inspection andMaintenance (I/M) Testing
Some state and provincial and localgovernments may haveInspection/Maintenance (I/M) programs toinspect the emission control equipment onyour vehicle. Failure to pass this inspectioncould prevent you from getting a vehicleregistration.
If the service engine soon indicatoris on or the bulb does not work,your vehicle may need service.See On-Board Diagnostics.
Your vehicle may not pass the I/M test if theservice engine soon indicator is on or notworking properly (bulb is burned out), or ifthe OBD-II system has determined that someof the emission control systems have notbeen properly checked. In this case, thevehicle is not ready for I/M testing.
If the vehicle’s engine or transmission hasjust been serviced, or the battery hasrecently run down or been replaced, theOBD-II system may indicate that the vehicleis not ready for I/M testing. To determine ifthe vehicle is ready for I/M testing, turn theignition key to the on position for 15 secondswithout cranking the engine. If the serviceengine soon indicator blinks eight times, itmeans that the vehicle is not ready for I/Mtesting; if the service engine soon indicatorstays on solid, it means that your vehicle isready for I/M testing.
The OBD-II system checks the emissioncontrol system during normal driving. Acomplete check may take several days.
If the vehicle is not ready for I/M testing, youcan perform the following driving cycleconsisting of mixed city and highway driving:
1. 15 minutes of steady driving on anexpressway or highway followed by 20minutes of stop-and-go driving with atleast four 30-second idle periods.
2.Allow your vehicle to sit for at least eighthours with the ignition off. Then, start thevehicle and complete the above drivingcycle. The vehicle must warm up to itsnormal operating temperature. Oncestarted, do not turn off the vehicle untilthe above driving cycle is complete.
If the vehicle is still not ready for I/M testing,you need to repeat the above driving cycle.
174
MKT (TP4) , enUSA, Edition date: 201803, Second-Printing
Engine Emission Control
