Diesel Exhaust Fluid (DEF) Warning Strategy (Emission Control)

Engine Controls and Fuel - 3.0L LM2 Diesel | Description and Operation | Document ID: 5190599 Diesel Exhaust Fluid (DEF) Warning Strategy (Emission Control) The reductant system supplies the Selective Catalyst Reduction (SCR) stage of the vehicle’s exhaust aftertreatment system with the Diesel Exhaust Fluid (DEF) required to reduce exhaust Oxides of Nitrogen (NOx) levels. The Engine Control Module (ECM) continuously monitors the performance of the emission system during operation When the conditions associated with a fault in the emission system operation are detected, the ECM activates the emission control feature and presents the driver with a series of prompts and warnings. Once initiated, emission control warnings grow increasingly more serious as the vehicle continues to be driven. The vehicle’s current warning status is not displayed on the scan tool. The series emission control warnings alert the driver that EGR/SCR system service is urgently needed.

Note

The Emission Control warning strategy is not used in model year 2014 and newer emergency vehicles.

Note

Performing this procedure will clear the Driver Information message for the applicable system. — If no DTC or symptom exists Perform the scan tool control function: Reductant System Tamper Service Bay Test — Perform only when the following warning message is displayed: Service Emission System / Service Exhaust Fluid System Warning Level 1 Warning Level 1 is triggered when the ECM first detects an EGR or SCR dosing inhibit fault. The Driver Information Center (DIC) displays the following messages: Service Emission System See Owner’s Manual Now 282 km (175 miles) until 105 km/h (65 mph) Max Speed The messages alternate every 5 seconds and remain in the DIC until acknowledged by the driver, however the mileage countdown remains displayed in the DIC. Warning Level 2 Warning Level 2 is triggered after the first mileage countdown expires without vehicle service. The driver will hear 4 chimes on entering Warning Level 2. The DIC displays the following messages: Service Emission System See Owner’s Manual Now Transitioning to 105 km/h (65 mph) Max Speed The messages alternate every 5 seconds in the DIC until acknowledged by the driver. Warning Level 3 Warning Level 2 automatically advances to Warning Level 3 after speed limit ramp down is complete or a key Off for at least 2 minutes. The driver will hear 4 chimes on entering Warning Level 3. The DIC displays the following messages: Service Emission System See Owner’s Manual Now Speed Limited to 105 km/h (65 mph) 120 km (75 miles) Until 89 km/h (55 mph) Max Speed The messages alternate every 5 seconds until acknowledged by the driver; however, the Speed Limited to 105 km/h (65 mph), remains displayed in the DIC. Vehicle speed is limited to 105 km/h (65 mph). Warning Level 4 Warning Level 4 is not used. Warning Level 5 Warning Level 5 is not used. Warning Level 6 Warning Level 6 is triggered when the second mileage countdown expires without vehicle service. The driver will hear 4 chimes on entering Warning Level 6. The DIC displays the following messages: Service Emission System See Owner’s Manual Now Transitioning to 89 km/h (55 mph) Max Speed The messages alternate every 5 seconds until acknowledged by the driver. Warning Level 7 Warning Level 6 automatically advances to Warning Level 7 after speed limit ramp down is complete or a key Off for at least 2 minutes. The driver will hear 4 chimes upon entering Warning Level 7. The series of 4 chimes will repeat every 3 minutes until the vehicle is serviced. The DIC displays the following messages: Service Emission System See Owner’s Manual Now Speed Limited to 89 km/h (55 mph) The messages alternate every 5 seconds until acknowledged by the driver, however, the Speed Limited to 89 km/h (55 mph), remains displayed in the DIC.