Warnings, Indicators, and Messages

Red

Stop Engine*

Indicates a serious fault that requires engine shutdown immediately. The engine protection system will reduce the maximum engine torque and speed, and, if the condition does not improve, will shut down the engine within 30 to 60 seconds.

Safely bring the vehicle to a stop on the side of the road and shut down the engine as soon as the red light is seen. If the engine shuts down while the vehicle is in a hazardous location, turn the key to the OFF position for a few seconds, then restart the engine and move the vehicle to a safer location.

Various

Red

Engine Oil Level Warning

Indicates engine oil is low. Find a safe location to stop and check engine oil level. Top off as needed.

Red

Low Engine Oil Pressure

Indicates the engine oil pressure is below the minimum allowable pressure.

ICUC Warning

Red

Engine Oil Temperature Warning

Red

Low Coolant Level

Red

High Coolant Temperature

Indicates the coolant temperature is above the maximum allowable temperature.

ICUC Warning

Amber

Check Engine*

Indicates an engine condition (low oil pressure, low coolant level, high coolant temperature, high DPF soot level, uncontrolled DPF regeneration, or battery voltage 11.9 volts or less) that requires correction.

Correct the condition as soon as possible. If the condition worsens, the STOP engine lamp will illuminate.

Various

Amber

Engine Malfunction Indicator Lamp (MIL)*

A steadily illuminated amber MIL lamp indicates an engine fault that effects emissions.

Amber

Engine Malfunction Indicator Lamp (MIL)*

Alternate Engine Malfunction Indicator lamp.

A steadily illuminated amber MIL lamp indicates an engine fault that effects emissions.

Amber

Engine Oil Level Caution

Amber

Engine Oil Pressure Caution

Amber

Low Coolant Level Caution

Amber

High Coolant Temperature Caution

Amber

Start Blocked

Indicates that the system is preventing the starter from cranking. This can occur when the ignition switch is turned to START before the gauge sweep has completed.

Turn the ignition switch back to ON, wait for the message to turn off, then turn the ignition switch to START again.

ICUC Notice

Amber

Start Blocked

Alternative Telltale for Start Blocked.

Green

Start Engine

Green

Optimized Idle Active

Indicates optimized idle is active.

Red

Transmission Fluid Level Warning

Indicates low transmission fluid level.

Safely bring the vehicle to a stop as soon as possible.

Amber

Caution Check Transmission

Indicates an undesirable transmission condition.

Amber

Low Transmission Fluid Level Caution

Indicates low transmission fluid level.

Amber

High Transmission Temperature

Indicates transmission is overheating.

ICUC Caution

Red

Low Brake Air Pressure (EPA10 and Newer)

Indicates air pressure in the primary or secondary reservoir has dropped below approximately 70 psi (483 kPa).

Red

Low Brake Air Pressure (EPA10 and Newer)

Alternate low brake air pressure telltale. Indicates air pressure in the primary or secondary reservoir has dropped below approximately 70 psi (483 kPa).

ICUC Warning

Red

Parking Brake Engaged

(EPA10 and Newer)

Indicates the parking brake is engaged.

Red

Parking Brake Engaged

(EPA10 and Newer)

Alternative icon indicating the parking brake is engaged.

Amber

Winch Brake Caution

Amber

Work Brake Caution

Amber

Electronic Stability Control (ESC) Active

Flashing indicates a stability event has been detected, and the ESC system is active.

Solid illumination indicates a problem with the stability system. Repair the ESC system immediately to ensure full stability capability.

Amber

Electronic Stability Program Off

Amber

Tractor Anti-Lock Braking System (ABS)

Momentary illumination indicates the vehicle ABS is engaged.

Solid illumination indicates a problem with the vehicle ABS.

Repair the ABS immediately to ensure full braking capability.

Amber

Trailer Anti-Lock Braking System (ABS)

Momentary illumination indicates the trailer ABS is engaged.

Solid illumination indicates a problem with the trailer ABS.

Repair the ABS immediately to ensure full braking capability.

Amber

Active Brake Assist Active

Indicates Active Brake Assist is engaged.

Amber

Active Brake Assist Unavailable (GHG14 and newer)

Indicates the Active Brake Assist system is not available.

ICUC Caution

ICUC Telltale

Amber

Adaptive Cruise Control Not Available

Indicates that Adaptive Cruise Control (ACC) is not available

ICUC Caution

If ACC is not available, Active Lane Assist (ALA) will not be available.

Amber

Hill Holder Assist Off

Amber

Hill Start Aid Engaged

Grey

Brake Hold Mode Engaged

Indicates that brake hold mode is active.

The service brake remains engaged when the driver takes their foot off the brake pedal.

Brake hold mode is released when the accelerator pedal is pressed, the service brake is set, or the park brake is set.

Green

Descent Cruise Control Mode Engaged

Green

Engine Brake Engaged

Indicates the engine brake is enabled.

Amber

IPPC Error

Green

Adaptive Cruise Control Active

Red

Adaptive Power Steering (APS) Error

An error with APS deactivates Active Lane Assist (ALA).

Amber

Gear Teach Mode in Progress

Green

AERO active

Indicates that aerodynamic height control (AERO) is active.

Amber

Suspension Higher than Normal Ride Height / Axle Lifted

Indicates the current rear suspension height is above the normal ride height.

ICUC Caution

Amber

Suspension Lower Than Normal Ride Height / Axle Dropped

Indicates the current rear suspension height is below the normal ride height.

ICUC Caution

Amber

Suspension Height

Amber

5th Wheel Adjust

Red

Battery Critical

Red

Battery Failure

Amber

Battery Failure

Telltale

Color

Description

Related Messages

Red

Low Tire Pressure Warning

Indicates a notable loss of tire pressure in at least one tire.

If a tire monitoring system is available, the tire(s) with low pressure will be highlighted red.

Amber

Low Tire Pressure Warning

Indicates low tire pressure in at least one tire.

If a tire monitoring system is available, the tire(s) with low pressure will be highlighted amber.

Amber

Automatic Traction Control (ATC) Active

Flashing indicates a wheel spin event has been detected, and the ATC system is active.

Amber

Automatic Traction Control (ATC) Deactivated

Indicates the ATC SPIN button has been pressed to allow wheel slip.

ICUC Caution

Amber

Low Fuel

Indicates low fuel level.

Refill the main fuel tank.

Amber

Water in Fuel Warning

Indicates the fuel may contain water.

Drain any water collected in the fuel/water separators.

Red

Diesel Particulate Filter Critical

Indicates a parked regen is required immediately.

ICUC Warning

Amber

Diesel Particulate Filter (DPF) Status

Solid illumination indicates a regen is required. Change to a more challenging duty cycle (such as highway driving) to raise exhaust temperatures for at least twenty minutes, or perform a parked regen.

Blinking indicates that a parked regen is required immediately. An engine derate and shutdown will occur.

ICUC Caution

Amber

Diesel Particulate Filter Inhibited

Occurs only when the regent inhibit switch is pressed.

Green

Diesel Particulate Filter Regeneration in Progress

Indicates a regen is in progress.

Amber

High Exhaust System Temperature (HEST)*

Slow (10-second) flashing indicates a regeneration (regen) is in progress.

IMPORTANT: When the HEST lamp is illuminated, do not park the vehicle near objects that can be harmed by high temperatures or flammable materials.

Solid illumination indicates high exhaust temperatures at the outlet of the tail pipe when speed is below 5 mph (8 km/h).

Amber

Low Diesel Exhaust Fluid

Indicates low diesel exhaust fluid.

Fill the DEF tank.

See Greenhouse Gas Emissions and Fuel Consumption Standards for an explanation of the after treatment system (ATS) warnings, and actions required to avoid further engine protection steps.

Amber

Low Diesel Exhaust Fluid

Alternative icon to indicate Low Diesel Exhaust Fluid.

Fill the DEF tank.

See Greenhouse Gas Emissions and Fuel Consumption Standards for an explanation of the after treatment system (ATS) warnings, and actions required to avoid further engine protection steps.

Green

Right-Turn Indicator On

Flashing indicates the outside right-turn signal lamps are activated.

Green

Left-Turn Indicator On

Flashing indicates the outside left-turn signal lamps are activated.

Blue

High-Beams On

Indicates the high-beam headlights are on.

Green

Low-Beams On

Indicates the low-beam headlights are on.

Blue

Automatic High-Beams On

Indicates the high-beam headlights have been set to automatic and are on.

Grey

Automatic High-Beams Off

Indicates the high-beam headlights have been set to automatic and are off.

Green

Automatic Low-Beams On

Indicates the low-beam headlights have been set to automatic and are on.

Grey

Automatic Low-Beams Off

Indicates the low-beam headlights have been set to automatic and are off.

Green

Daytime Running Lamps On

Indicates the daytime running lamps are on.

Blue

Auxiliary Drive Lamps On

Indicates the auxiliary drive lamps are on.

Blue

Utility Lamps On

Indicates the utility lamps are on.

Green

Taillights / Marker Lamps On

Indicates the taillights, aka marker lamps, are on.

Red

Unfastened Seat Belt

On some vehicles, activates with an audible alert when the system detects that the parking brake is off and the driver seat belt is not fastened.

On vehicles with a seat occupancy sensor, the seat being occupied, seat belt not fastened, and parking brake off will cause this warning to activate.

On other vehicles, this lamp illuminates for 15 seconds when the ignition is first turned on.

Amber

Supplemental Restraint System (SRS) Error

Illuminates when ignition is turned on and then goes off.

Telltale not illuminating when ignition turns on or remaining lit indicates a malfunction in the restraint system. Restraint system components may be triggered unintentionally or may not deploy as intended during an accident.

Have the restraint system checked and repaired immediately.

White

Snowflake

Indicates ambient air temperature has dropped below 34°F (1°C).

Pay attention to road conditions and watch for ice.

ICUC Caution

Blue

Active Phone Call

Indicates a phone is connected to the ICU and a call is active.

The phone screen in the infotainment section of the ICU will also show an active call, including the number being called and call length.

Red

Primary Air Warning

Red

Secondary Air Warning

Red

Application Air Warning

Amber

Primary Air Caution