General Information

Common Warning and Indicator Lamps and ICU Messages

Lamp Description

Color

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.

Red

High Coolant Temperature

Indicates the coolant temperature is above the maximum allowable temperature.

Red

Low Air Pressure (EPA07)

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

Red

Low Air Pressure (EPA10 and Newer)

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

Red

Low Air Pressure (ICU4Me only)

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

NOTE: On EPA 2016 and newer vehicles, this text pop-up warning appears on the ICU4Me screen and an audible warning buzzer sounds. However, the low air pressure warning telltale under the ICU4Me screen does not illuminate.

–

Low Engine Oil Pressure

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

Red

Transmission Overheat

Indicates high transmission temperature.

Red

Transmission Fluid Level

Indicates low transmission fluid level. Safely bring the vehicle to a stop as soon as possible.

Red

Parking Brake (EPA07)

Indicates the parking brake is engaged, or hydraulic brake fluid pressure is low. An audible alert activates when the vehicle is moving over 2 mph (3 km/h) with the parking brake set.

Red

Parking Brake (EPA10 and Newer)

Indicates the parking brake is engaged.

Red

Low Battery Voltage

Indicates that battery voltage is 11.9 volts or less.

Red

Unfastened Seat Belt

Activates with an audible alert when the system detects that the parking brake is off and the driver seat belt is not fastened on some vehicles. On other vehicles, this lamp illuminates for 15 seconds when the ignition is first turned on.

Red

Check ECAS

Indicates Electronically Controlled Air Suspension (ECAS) active fault.

Red

CHECK Engine^*

Indicates an engine condition (low oil pressure, low coolant level, high coolant temperature, high DPF soot level, or uncontrolled DPF regeneration) that requires correction. Correct the condition as soon as possible. If the condition worsens, the STOP engine lamp will illuminate.

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 flammable material.

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

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.

Amber

Malfunction Indicator Lamp (MIL)

Indicates an emissions-related fault. See the engine operation manual for details.

Amber

Vehicle 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 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

No Charge

Indicates the alternator is not properly powering the electrical system.

Amber

Water in Fuel

Indicates the fuel may contain water. Drain any water collected in the fuel/water separators.

Amber

Fuel Filter Restriction

Indicates the fuel filter is clogged and requires service.

Amber

Optimized Idle

Indicates optimized idle is enabled.

Amber

Check Transmission

Indicates an undesirable transmission condition.

Amber

Wait To Start (EPA07/EPA10)

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, or if the starter has overheated.

Turn the ignition switch back to ON, wait for the lamp to go out, then turn the ignition switch to START again.

Amber

Start Blocked (GHG14 only)

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, or if the starter has overheated.

NOTE: Illumination of the Start Blocked lamp does not indicate a problem with the starter.

Turn the ignition switch back to ON, wait for the lamp to go out, then turn the ignition switch to START again.

Amber

Wheel Spin (pre-EPA16)

Flashing indicates the ATC system is active, or the ATC button has been pressed to allow wheel slip.

Solid illumination indicates ATC is shut off or unavailable due to a system fault. In the event of a system fault, repair the ATC system immediately to ensure full braking capability.

Amber

Stability Event (EPA16 and newer)

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

ATC Deactivated (EPA16 and newer)

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

Solid illumination indicates ATC is shut off or unavailable due to a system fault. In the event of a system fault, repair the ATC system immediately to ensure full braking capability.

Amber

Roll Stability (pre-EPA16)

Momentary illumination indicates that a stability event has occurred.

On vehicles that are also equipped with ATC, flashing indicates the ATC button has been pressed to allow wheel slip.

Solid illumination indicates ATC is shut off or unavailable due to a system fault. In the event of a system fault, repair the ATC system immediately to ensure full braking capability.

Amber

Hill Start Aid (HSA) Override

Indicates the HSA switch has been pressed to override the hill start assist feature.

Amber

Outside Normal Ride Height

Indicates the current rear suspension height is not at the normal ride height. This light will turn off once the vehicle returns to normal ride height.

Amber

Bulb Out (optional)

Indicates that a bulb is not functioning in the headlights, tail lights, parking lights, or marker lights.

Amber

Engine Brake

Indicates the engine brake is enabled.

Green

Left-Turn Signal

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

Green

Right-Turn Signal

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

Green

Cruise Control

Indicates the cruise control is enabled.

NOTE: The ICU4Me does not have a green cruise control telltale.

Green

Active Brake Assist (GHG14 and newer)

Indicates the Active Brake Assist system is not available.

Amber

Lane Departure Warning

Indicates that lane departure warning is disabled due to minimum speed, no lane markings, or system not available.

NOTE: Only on vehicles equipped with Detroit Assurance radar.

Amber

High-Beam Headlights

Indicates the high-beam headlights are on.

Blue