BOLT-SPECIAL 2026450 - Caterpillar

Diagnostic Codes
Refer to Electronic Troubleshooting for an explanation of each diagnostic code.Active Diagnostic Codes
Diagnostic codes are used by the ECM in order to warn the vehicle operator of a problem. The diagnostic codes also indicate the nature of the problem to the service technician. Some codes are only used to record an event. These codes do not indicate problems that need repair.An "ACTIVE" diagnostic code represents a problem. The problem should be investigated and the problem should be corrected as soon as possible. Repairing the cause of an "ACTIVE" code will cause the code to be cleared.If an "ACTIVE" code is generated, the diagnostic lamp will turn on and the diagnostic lamp will remain on. The diagnostic lamp will blink at 5 second intervals. If the condition that generates the fault only occurs for a brief moment, the diagnostic lamp will turn off after five seconds. In this situation, the code will be logged.Some diagnostic codes cause the ECM to make major changes in the engine operation or limits. The major changes occur as a result of the code that was generated.Logged Diagnostic Codes and Events
When the ECM generates a diagnostic code, the ECM usually logs the code in permanent memory within the ECM. The ECM has an internal diagnostic clock. The ECM records the time when a code is logged. Knowing the time and the frequency of the code can be a valuable tool to a technician that is troubleshooting intermittent problems. Logged codes can be downloaded or erased with an electronic service tool.Diagnostic Codes that are logged repeatedly may indicate a problem that needs special investigation. Codes that are logged a few times may not need any attention until a scheduled maintenance interval if the codes do not result in complaints from the driver.Refer to Electronic Troubleshooting, "Troubleshooting Diagnostic Codes" in order to troubleshoot a logged diagnostic code. If symptoms continue, refer to Electronic Troubleshooting, "Troubleshooting Without a Diagnostic Code".Note: The most likely cause of an intermittent problem is a faulty connection or damaged wiring. The next likely cause is a component failure (sensor or switch for example). The least likely cause is the ECM.Certain diagnostic codes only record an event. These events are not a performance problem. In these cases, troubleshooting is not required.Electronic Service Tools
Caterpillar electronic service tools are designed to help the service technician perform the following tasks:
Identify faults.
Diagnose system problems.
Calibrate timing.
Program parameters.
Read trip data.
Read sensor outputs.
Read switch status.Refer to Electronic Troubleshooting for a list of service tools and procedures.