Warning and Indicator Lights
The ICU has three or four rows of warning and indicator lights with icon symbols, depending on the ICU configuration. The positions of the lights may vary, but the telltales are standard for all applications. See Table. for a listing of standard and commonly used warning and indicator lamps.
Warning and indicator lamps illuminate in red (danger), amber (caution), green (status advisory), or blue (high-beam headlights active).
Important: Depending upon local jurisdictional emissions guidelines, vehicles and/or engines that are domiciled outside of the U.S. and Canada may not be compliant with EPA10 or GHG21 regulations. Noncompliant vehicles may not be equipped with all of the warning and indicator lamps shown in Table..
Table 1, Common Warning and Indicator Lamps
|
Common Warning and Indicator Lamps |
|||
|
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 (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, mid-GHG14) |
Indicates air pressure in the primary or secondary reservoir has dropped below approximately 70 psi (483 kPa). |
— |
 |
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 (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 |
 |
Check Transmission |
Indicates an undesirable transmission condition. |
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. 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 |
 |
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 |
 |
High-Beam Headlights |
Indicates the high-beam headlights are on. |
Blue |
Table 1, Common Warning and Indicator Lamps
* See Fig. for an explanation of the aftertreatment system (ATS) warning indicators, and actions required to avoid further engine protection steps.
Engine Protection System
Warning: When the red STOP engine lamp illuminates, most engines are programmed to shut down automatically within 30 seconds. The driver must immediately move the vehicle to a safe location at the side of the road to prevent causing a hazardous situation that could cause bodily injury, property damage, or severe damage to the engine.
See Fig. for an explanation of the aftertreatment system (ATS) warning indicators, and actions required to avoid further engine protection steps.
The STOP engine lamp illuminates when the engine protection system is activated in one of two ways. On some engines, the engine protection system will derate the engine, allowing it to run at lower rpm and slower vehicle speed. Drive the vehicle to a safe location or to a service facility.
Fig. 1, ATS Warning Lamps
Important: 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.
On other engines, the engine protection system will shut down the engine. It will first derate the engine, then shut it down completely 30 to 60 seconds after the indicator illuminates (depending on the critical fault type) if the condition does not improve. Bring the vehicle to a stop on the side of the road before the engine shuts down.
Some vehicles may have a shutdown-override switch, which may be used to momentarily override the shutdown sequence. See Engine Starting Procedure for detailed information regarding the shutdown process.
Important: Do not attempt to restart the engine while the vehicle is moving. Bring the vehicle to a safe stop, then restart the engine.
To restart the engine, turn the ignition to OFF, leave it there a few seconds, then turn the ignition to START. The engine will run for a short period and shut down again if the condition does not improve.