RETAINER 1U0725 - Caterpillar

Self-Diagnostics
The electronic control system has the ability to detect problems. When a problem is detected, a diagnostic trouble code is generated and the amber warning lamp is illuminated. In most cases, the code is also logged in the Engine Control Module (ECM).Some codes indicate that there is a problem with the control system. Open circuits or short circuits are examples of these types of problems. Some codes provide information about an undesirable engine operating condition. Low oil pressure or low temperature at the inlet of the Diesel Particulate Filter (DPF) are examples of these types of problems.When codes occur, the codes are active. Active codes indicate that a problem of some kind currently exists. Always troubleshoot active codes before any other work is performed. If a truck is brought in with an active code, find the code in this manual and proceed to diagnose the cause of the code.Codes that are stored in the ECM are logged. Logged codes do not necessarily indicate that something needs to be repaired. The problem may have been temporary, or the problem may have been repaired since the problem was logged. Logged codes may result from intermittent problems.Some codes require passwords in order to be cleared from memory. Codes that do not require passwords to be cleared from memory are automatically deleted after 100 hours of engine operation.Refer to Troubleshooting, "Diagnostic Trouble Code List" for a complete list of the codes that apply to these engines.Engine Snapshot Data
Whenever most codes occur, the ECM records the time in engine hours of the occurrence. Also, the ECM records the operating parameters of the engine for nine seconds before the code and three seconds after the code. This is called a snapshot. The operating parameters of the engine that are recorded are similar to the operating parameters of the engine that are displayed in the status screens of the Caterpillar Electronic Technician (ET). Not all of the status screens of Cat ET or parameters are recorded.A snapshot can also be triggered from the cruise control's "Set/Resume" switch. In order to trigger a snapshot from the cruise control's "Set/Resume" switch, quickly toggle the switch to the SET position. Then, quickly toggle the switch to the RESUME position. You can also toggle the cruise control's "Set/Resume" switch from the RESUME position to the SET position.A snapshot can also be triggered from Cat ET.