ENGINE OPERATION - Emergency - What To Do If sudden loss of coolant. Follow these steps if the engine is overheating. 1 Debris blocking air flow through the cooling module (radiator) Check Engine Lamp - Turns on when a problem exists, but the vehicle can still be safely driven. Vehicle should be serviced to correct the problem but the situation should not be considered an emergency. If the engine coolant temperature warning lamp comes on and the audible alarm sounds showing an overheat condition, or if you have any other reason to suspect the engine may be overheating, DO NOT TURN OFF THE ENGINE unless a low water warning device indicates a loss of coolant. Follow these steps:
CAUTION The lamp will also illuminate when a DPF regeneration or addition of diesel exhaust fluid (DEF) is required. For PACCAR PX Engines, this icon may also illuminate if the crankcase breather element needs attention. Another function of the check engine lamp is to warn the operator of an impending idle shutdown. When the idle shutdown timer is 30 seconds from expiring, the ECM begins flashing the check engine warning lamp once per second. When the timer expires, the ECM will turn off the warning lamp and shut down the engine. The cooling system may overheat if the engine coolant is at the minimum level.
A sudden loss of coolant, caused by a split hose or broken hose clamp could also lead to an overheat condition. Always inspect to ensure hoses and clamps are not cracked, worn, or loose. Failure to comply may result in equipment or property dam- age. Follow these steps if the engine coolant temperature is rising, or the temperature is already above normal, and there are no other warning alarms displayed in the instrument cluster. 1. Reduce engine speed, or stop. When stopped, place the transmission in neutral (N) and set the parking brake. Keep the engine running. See the vehicle operator's manual for instructions on transmission shifting and parking brake information.
NOTE Engine is Overheating The system may also temporarily over- heat during severe operating condi- tions such as: The cooling system may overheat if the coolant level is below normal or if there is Climbing a hill on a hot day Stopping after high-speed/high- load driving Y53-1183-1E1 (04/16/18) 13