HUB 2D3467 - Caterpillar

The Electronic Control Module (ECM) monitors various systems on the engine. The systems are monitored in order to detect any abnormal operating conditions. Specific functions that are monitored by the ECM include the following items:
Low engine oil pressure
High engine coolant temperature
Engine overspeed
Air inlet restriction
Engine fuel filter restriction
Engine oil filter restriction
Exhaust temperatures
Low coolant pressure
High aftercooler temperature
High crankcase pressure
Low engine oil level
Automatic altitude compensationFor details on the trip points, refer to the engines Troubleshooting manual.Low Engine Oil Pressure
The ECM monitors the engine oil pressure by measuring an electrical signal from the oil pressure sensor. The oil pressure sensor is located on the filter outlet elbow. The filter outlet elbow is located on the front left corner of the engine. The ECM compares the actual engine oil pressure to an oil pressure map. The map is stored in the ECM memory. The map represents the minimum acceptable oil pressure. The map is based upon engine speed. If the oil pressure drops below the minimum acceptable level, the ECM will activate the low oil pressure warning. This warning will be displayed on the monitoring panel. Also, an event will be logged in the ECM memory. Factory passwords are required to clear logged events.High Engine Coolant Temperature
The ECM monitors the engine coolant temperature by measuring an electrical signal from the engine coolant temperature sensor. The coolant temperature sensor is located in the housing for the coolant temperature regulators. The ECM compares actual coolant temperature to the maximum allowable limit. If the temperature of the engine coolant exceeds the trip point, the ECM will send the high coolant temperature warning to the monitoring panel. The warning will remain activated until the coolant temperature drops below the hysteresis. The event is logged in the permanent ECM memory. Factory passwords are required to clear this information.Engine Overspeed
The ECM determines the engine speed by measuring an electrical signal from the speed/timing sensor. The sensor is located on the flywheel housing. The sensor is next to the left camshaft drive gear. If engine speed exceeds the trip point, an operator warning is given. The warning will remain active until the engine speed drops below the hysteresis. The peak engine overspeed is logged in the permanent ECM memory. The peak engine overspeed is logged as a histogram in order to quantify the magnitude of the engine overspeed. The histogram provides information in order to assess the potential level of engine damage. Factory passwords are required to clear this information.Engine Fuel Filter Restriction
The engine utilizes two fuel pressure sensors, one being unfiltered fuel and the other being filtered fuel. The sensors are located in the fuel filter housing. The sensors provide signals to the ECM. The ECM sends a signal to the monitoring panel via the data link. The monitoring panel will warn the operator when the restriction of the fuel filter reaches an unacceptable level. An event will also be logged in the ECM. The event can be viewed with the electronic service tool. The event can also be