MANIFOLD-EXHAUST 1150556 - Caterpillar

Active Diagnostic Trouble Codes
An active diagnostic trouble code indicated that a problem with the electronic control system exists at this time. Correct the problem as soon as possible.When the ECM generates an active diagnostic trouble code, the amber warning lamp is illuminated in order to alert the operator. If the condition that generated the code is momentary, the warning lamp is turned off and the diagnostic trouble code becomes logged.Logged Diagnostic Trouble Codes
When the ECM generates a diagnostic trouble code, the ECM logs the code in permanent memory. The ECM has an internal diagnostic clock. The ECM records 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 codeThis information is a valuable indicator for troubleshooting intermittent problems.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 100 hours.
A new code is logged and there are already ten codes in memory. In this case, the oldest code is cleared.Some diagnostic trouble codes may be easily triggered. Some diagnostic trouble codes may log occurrences that did not result in complaints by the operator. The most likely cause of an intermittent problem is a faulty connection or damaged wiring. The next likely cause is a component failure. The least likely cause is the failure of the control module. Diagnostic trouble codes that are logged repeatedly may indicate a problem that needs special investigation.Note: Always clear logged diagnostic trouble codes after investigating and correcting the problem which generated the code.