Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Level)

DIESEL EXHAUST FLUID (DEF) WARNING STRATEGY (DEF LEVEL)
(Vehicles With VIN L, RPO LGH Only)

An adequate on-board supply of Diesel Exhaust Fluid (DEF) is critical for the reduction of exhaust Oxides of Nitrogen (NOx) levels within the Selective Catalyst Reduction (SCR) stage. This vehicle provides the driver with an elaborate series of prompts and warnings that are initiated when the DEF level falls below a calibrated value.

The Engine Control Module (ECM) monitors the DEF level and consumption rate in order to calculate an estimated range in miles remaining until the DEF reservoir is empty. DEF levels are detected by the 3-position solid-state DEF level sensor. Typically, DEF warnings begin once the estimated mileage falls below 1,609 km (1,000 mi). Once initiated, DEF warnings grow increasingly more serious as the remaining mileage decreases without a DEF refill. The vehicle's current DEF warning level is displayed on the scan tool as Reductant Level Warning Indicator Command Level 1 through Level 9.

Warning Level 1
Warning Level 1 is triggered when the DEF level falls below the top-most position of the DEF Level Sensor and the estimated range remaining is greater than 1609 km (1000 mi). No prompts or warnings are presented to the driver.

Warning Level 2
Warning Level 2 is triggered when the estimated range remaining falls below 1,609 km (1,000 mi) based on current DEF consumption rates. The Driver Information Center displays the message Exhaust Fluid Range X MI, where X is the estimated range remaining in miles. This message remains on the Driver Information Center until acknowledged by the driver.

Warning Level 3
Warning Level 2 automatically advances to Warning Level 3 when the ECM detects an ignition ON to ignition OFF event. A level 3 warning remains active as long as the estimated range remaining is greater than 483 km (300 mi) based on current DEF consumption rates. No prompts or warnings are presented to the driver.

Warning Level 4
Warning Level 4 is triggered when the estimated range remaining falls below 483 km (300 mi) based on current DEF consumption rates. The message Exhaust Fluid Range X MI, where X is the estimated range remaining in miles is displayed on the Driver Information Center. This message is also displayed at the beginning of each ignition cycle. This message remains on the Driver Information Center until acknowledged by the driver.

Warning Level 5
Warning Level 5 is triggered when the estimated range remaining is less than approximately 121 km (75 mi) based on current DEF consumption rates. The message Exhaust Fluid Low - Speed Limited Soon, is displayed on the Driver Information Center. This message is also displayed at the beginning of each ignition cycle. This message remains on the Driver Information Center until acknowledged by the driver.

Warning Level 6
Warning Level 6 is triggered when the estimated range remaining is less than approximately 0 km (0 mi) based on current DEF consumption rates. The driver will hear 4 chimes on entering Warning Level 6. The Driver Information Center displays the following messages:

• Exhaust Fluid Empty Refill Now
• 89 km/h (55 mph) Max Speed Upon Restart

The messages are also displayed at the beginning of each ignition cycle. The Exhaust Fluid Empty Refill Now message remains on the Driver Information Center until acknowledged by the driver. The 89 km/h (55 mph) Max Speed Upon Restart message is not acknowledgeable.

At the next ignition ON event, the system will advance from Warning Level 6 to Warning Level 7. If fuel is added to the vehicle without an ignition cycle the system will advance to Warning Level 8.

In the event of a refill, the scan tool may show that fluid has been added, but the vehicle may not release from the warning level unless it is driven greater than 6 mph (10 km/h) for approximately 5 minutes.

Warning Level 7
Warning Level 7 is active at the next ignition ON event. The driver will hear 4 chimes on entering Warning Level 7. The 4 chimes are repeated 3 more times during this ignition cycle. The Driver Information Center displays the following messages:

• Exhaust Fluid Empty Refill Now
• Speed Limited to 89 km/h (55 mph)

The messages are alternately displayed every 5 seconds on the Driver Information Center. Both messages remain on the Driver Information Center until acknowledged by the driver; however, the Speed Limited to 89 km/h (55 mph), remains locked on the Driver Information Center.

The DEF Indicator in the instrument panel flashes continuously. Warning Level 7 remains active until a refueling event is detected.

Vehicle speed is now limited to 89 km/h (55 mph) maximum.

In the event of a refill, the scan tool may show that fluid has been added, but the vehicle may not release from the warning level unless it is driven greater than 6 mph (10 km/h) for approximately 5 minutes.

Warning Level 8
Warning Level 8 is triggered when the ECM detects that additional fuel was added without a refill of the DEF reservoir. The driver will hear 4 chimes on entering Warning Level 8. The 4 chimes will repeat 2 more times during this ignition cycle. The Driver Information Center displays the following messages:

• Exhaust Fluid Empty Refill Now
• Speed Limited to 89 km/h (55 mph)
• 6 km/h (4 mph) Max Speed Next Fuel Fill

The messages are alternately displayed every 5 seconds on the Driver Information Center. The three messages remain on the Driver Information Center until acknowledged by the driver. Once acknowledged, the Speed Limited to 89 km/h (55 mph), and 6 km/h (4 mph) Max Speed at Next Fuel Fill, remain locked on the Driver Information Center.

The DEF Indicator in the instrument panel flashes continuously. The vehicle remains in Warning Level 8 until the DEF reservoir is refilled or a second refueling event is detected.

Vehicle speed is limited to 89 km/h (55 mph) maximum.

In the event of a refill, the scan tool may show that fluid has been added, but the vehicle may not release from the warning level unless it is driven greater than 6 mph (10 km/h) for approximately 5 minutes.

Warning Level 9
Warning Level 9 is triggered on the next ignition cycle following a second refueling event without a refill of the DEF reservoir. The driver will hear 4 chimes on entering Warning Level 9. The 4 chimes will repeat every 3 minutes until the DEF reservoir is refilled. The Driver Information Center displays the following messages:

• Exhaust Fluid Empty Refill Now
• Speed Limited to 6 km/h (4 mph)

The messages are alternately displayed every 5 seconds on the Driver Information Center. Both messages remain on the Driver Information Center until acknowledged by the driver; however, the Speed Limited to 6 km/h (4 mph) Max, message remains locked on the Driver Information Center.

The DEF Indicator in the instrument panel flashes continuously. The vehicle remains in Warning Level 9 until the DEF reservoir is refilled.
Vehicle speed is limited to 6 km/h (4 mph) maximum.