Refer to Systems Operation, "Electronic Control System Components" for diagnostic codes and for diagnostic code information. For an explanation of each diagnostic code, refer to Troubleshooting.
Diagnostic codes are used by the engine system to warn the operator of a problem. Also, diagnostic codes are used by the engine system to indicate the nature of a problem to the service technician. Some codes are used only to record an event. These codes do not indicate problems that need repair.
An "ACTIVE" diagnostic code represents a problem that should be investigated promptly. The problem should be corrected as soon as possible. Repairing the cause of an "ACTIVE" code will cause the code to be cleared.
When an "ACTIVE" code is generated, the diagnostic lamp will turn on and the diagnostic lamp will remain on. While the diagnostic lamp is turned on, the diagnostic lamp will blink at five second intervals. This is called the flash code. If the condition that generates the fault occurs for only a brief moment, the lamp will turn off after five seconds. In this situation, the code will be logged.
Logged Diagnostic Codes And Events
When the ECM generates a diagnostic code, the code will be active and the code will be logged in memory within the ECM. The ECM has an internal diagnostic clock and the ECM will record the time for the fault logging. Knowing the time and frequency of the code can be a valuable indication when a technician is troubleshooting intermittent problems. Logged codes can be downloaded or erased with an electronic service tool. These logged codes can also be a valuable indication when a technician is troubleshooting intermittent problems.
In most cases, it is not necessary to stop the engine because of an intermittent code. However, the operator should retrieve the code. The operator should reference the appropriate information that will identify the nature of the event. The operator should note the circumstances that are involved during the time that the light was on.
Certain fault codes and/or event codes cause the system to make major changes in the following parameters:
- engine speed
- engine speed limits
These changes result from the generation of the code.
Note: The most likely cause of an intermittent problem is a faulty connection or damaged wiring. The next most likely cause of an intermittent problem is a component failure. A sensor or a switch are typical examples of components that could fail. The least likely cause of an intermittent problem is the ECM.
The Caterpillar electronic service tools for the electronic control systems are designed to help the service technician analyze diagnostic codes and problems within the system. Also, the Caterpillar electronic service tools for the electronic control systems are designed to help the service technician locate diagnostic codes and problems within the system. The electronic service tool is required to perform sensor calibrations and the electronic service tool is required in order to monitor programmable parameters of the engine. Also, the electronic service tool is required in order to change programmable parameters of the engine. For a list of service tools and procedures, refer to Troubleshooting.