PLUNGER 6P8848 - Caterpillar

Illustration 1 g01873681
Temperature conditions for typical temperature sensors determine when an ECM activates an event code and/or a diagnostic code for the sensor circuit.
Event codes are activated by an ECM when a transmission system condition is detected that is outside of the expected normal system range. The detected condition is within the operational range of the sensor that is being used to monitor the system.When the ECM detects a sensor signal that is out of the sensor operational range, a diagnostic code will be activated. Generally, a diagnostic code and an event code will not be activated at the same time for the system and the sensor. If an event and a diagnostic code are both activated on a sensor, resolve the cause of the diagnostic code before troubleshooting the active event. Resolving the cause of the diagnostic code could also cause the event to clear.The circuit or sensor is often not the cause of an active event as the signal is still within the sensor operational range. The most likely cause of the active event will be machine conditions that result in an abnormal system condition. For a subsystem that is monitored by a temperature sensor, an active high temperature event could be caused by various conditions. Conditions such as low coolant levels, dirty filters, clogged intakes, or cooling fan problems. When an event is activated and a diagnostic code is not active for the involved sensor, always investigate the machine conditions. Suspect machine conditions causing the problem before suspecting the sensor as the cause of the problem.When a control module activates an event code, the operator or the technician will be alerted by an error message on the display. The message and / or an audible alarm will indicate the severity of the problem. All the active events will be logged by the ECM. The active events and the logged events can be viewed on the Monitoring System Display or Caterpillar Electronic Technician (Cat ET). Up to 127 logged event codes can be stored by the ECM.Warning Levels
The ECM will assign one of three warnings levels to an active event code according to the severity of the abnormal system condition. Each warning level requires a specific response from the operator. The warning levels and required operator response are listed below.Level 1
An active warning level 1 event alerts the operator that a machine system could require attention. Level 1 events are logged, not displayed. If a Level 1 event is repeatedly activated, investigate the possible cause of the problem at the first opportunity. Check the involved system condition or perform maintenance on the involved system.Level 2
An active warning level 2 event can require a change in the operation of the machine to correct a problem. A warning level 2 event can indicate the need for a maintenance procedure. A level 2 warning that remains active or is repeatedly activated should be investigated at the earliest opportunity. Failure to correct the problem may result in the problem becoming more