Both the master ECM and the slave ECM can indicate active events. The master ECM will diagnose all of the events that are applicable to G3500 engines that have a single ECM. The events that are diagnosed by the slave ECM are a subset of the events that are diagnosed by the master ECM. All of the events that are pertinent to the slave ECM have the same setting conditions and the same conditions for clearing as the master ECM.
Event codes alert the operator that an abnormal engine operating condition such as low oil pressure or high coolant temperature has been detected. Events do not indicate problems with the electronic system. Event codes also indicate the nature of the problem. The Caterpillar Electronic Technician (ET) is designed to run on a personal computer. Event codes may be viewed on a personal computer that has the Cat ET software.
Illustration 1 represents the operating range of an oil temperature sensor. The diagram is a reference. Do not use the diagram to troubleshoot the oil temperature sensor.
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| Illustration 1 | g00791619 |
Typical operating range of an oil temperature sensor (1) In these areas, the output voltage of the sensor is too high or too low. The output is outside of the normal range. The electronic problem will generate a diagnostic code. (2) In this area, the oil temperature above 102 °C (216 °F) is higher than normal. The output voltage of the sensor will generate an event code for a warning or a shutdown for high oil temperature. The sensor does not have an electronic problem. (3) This area represents the normal operating temperature for the engine oil. The normal output voltage of the sensor is between 0.2 and 4.1 volts. | |
The following format is used for event codes:
- "EXXX (X) Description of the code"
The "E" means that the code is an event code. The "XXX" represents a numeric identifier for the event code. The fourth "(X)" represents a numeric identifier for the severity of the code. This is followed by a description of the code. Refer to the following example:
- "E004 (3) Engine Overspeed Shutdown"
The numbers that indicate the severity of the event code are defined below:
Warning (1) - This condition represents a serious problem with engine operation. However, this condition does not require a shutdown.
Shutdown (3) - For this condition, the engine is shut down in order to help prevent possible engine damage.
These responses to certain events may be programmed into the ECM. If the responses are programmed, Cat ET can display the event. If the responses are not programmed, the display will not appear. However, the occurrence of any event will cause the event code to be logged in the ECM that detected the event.
Note: Do not confuse event codes with diagnostic codes. For information on diagnostic codes, see Troubleshooting, "Troubleshooting with a Diagnostic Code".
Perform the following tasks before you troubleshoot the event code:
- Gather enough information about the complaint in order to describe the symptom(s) adequately.
- Verify that the complaint is not due to normal engine operation.
- Repair all active diagnostic codes. See Troubleshooting, "Troubleshooting With A Diagnostic Code".
Troubleshooting
For basic troubleshooting of the engine, perform the following steps first in order to diagnose a malfunction.
- Gather information about the complaint from the operator.
- Verify that the complaint is not due to normal engine operation. Verify that the complaint is not due to error of the operator.
- Perform a visual inspection. Inspect the following items:
- Fuel supply
- Oil level
- Oil supply
- Wiring
- Connectors
- Fuel supply
- Check the diagnostic codes and event codes. Repair any active codes.
If these inspections do not reveal any problems, identify the probable causes with the procedures in this manual that best describe the symptoms. Check each probable cause according to the tests that are recommended.
Be sure to check the connectors. This is specially true for problems that are intermittent. See Troubleshooting, "Inspecting Electrical Connectors".
Narrow the probable cause. Consider the operator information, the conditions of operation, and the history of the engine.
Operator Information
Obtain the following information from the operator:
- The occurrence and the time of the occurrence
- Determine the conditions for the occurrence. The conditions will include the engine rpm and the load.
- Determine if there are any systems that were installed by the dealer or the customer that could cause the symptom.
- Determine whether any other occurrences happened in addition to the symptom.
Diagnostic Codes and Event Codes
Examine the following information regarding any codes:
- The probable cause of the symptom is correlated to the code.
- The code was generated when the symptom occurred.
- Codes that are repeatedly logged
- The complaint is not due to normal engine operation.
Other Symptoms
If other occurrences happened in addition to the symptom, investigate the following conditions:
- The other occurrences are related to the symptom.
- The symptoms have a probable cause that is common.
Active Event Codes
An active event code represents a problem with engine operation. Correct the problem as soon as possible.
Both the master ECM and the slave ECM can indicate active events. When an event code is active, the "Active Alarm" indicator ("Engine Control Alarm Status" on Cat ET) is activated in order to alert the operator. If the condition that generated the code is momentary, the message disappears. The event code will be logged in the memory of the ECM that detected the event.
Active event codes are listed in ascending numerical order on Cat ET. The code with the lowest number is listed first.
Logged Event Codes
The master ECM and the slave ECM can log events. When an ECM generates an event code the ECM logs the code in permanent memory. Each ECM has an internal diagnostic clock. Each ECM will record the following information when a code is generated:
- The hour of the first occurrence of the code
- The hour of the last occurrence of the code
- The number of occurrences of the code
This information can be helpful for troubleshooting intermittent problems. Logged codes can also be used to review the performance of the engine.
A code is cleared from memory when one of the following conditions occur:
- The service technician manually clears the code.
- The code does not recur for 1000 hours.
- A new code is logged and there are already ten codes in memory. In this case, the oldest code is cleared.
Logged events are listed in chronological order. The most recent event code is listed first.
Note: Always clear logged event codes after investigating and correcting the problem which generated the code.