RING GEAR 8M0777 - Caterpillar

Caterpillar Products:
AllService Magazine SEPD1728, 27 January 2014, "Auto Clearing of Diagnostics and Events from Electronic Control Module (ECM) {1901, 1920, 7610, 7620}". Disregard the information in the article that is listed above. Refer to the information in the following article.Caterpillar products listed above with Electronic Controls Modules (ECMs) have a feature to automatically clear Diagnostic Trouble Codes (DTCs) (diagnostics and events) from the log system if the DTCs are not active within a predetermined period of service meter hours (SMH). The auto clear functionality helps to make sure that the stored DTCs are current enough and ensure that the troubleshooting is still needed. If the DTC is not active in the auto clear time, then the problem may not be still existing. In this case, a technician does not need to spend time to troubleshoot an old problem that has likely already been corrected or is not happening often enough to determine the root cause. All ECUs ( ECMs) store only limited number of unique DTCs in the memory. The limit is generally around 30 DTCs (15 diagnostics and 15 events) but vary by flash file. All the parameters of auto clear are fixed in the ECM flash file.The auto clearing functionality is also required to ensure that the memory is not filled up with old data that could prevent new more relevant data from being stored. When memory allocated for logged events is full, a new event will not be stored as logged event. When memory allocated for diagnostics is full, a new logged diagnostic may overwrite existing logged diagnostics based on priority. Some ECM flash file configurations turn off the auto clear feature in order to store only predetermined number of logged DTCs in the ECM. Auto clearing of DTCs is common within our industries and other related industries.Note: The automatic clear feature is available on all ECMs for all Caterpillar products listed above. However, some products may not have the capability to utilize it.Note: For Tier 4 Engines and some Machines the critical DTCs [such as High Engine Coolant Temperature, Engine over speed and low engine oil pressure] will not Auto Clear. The rest of the DTCs will auto clear if the DTC is not active in the auto clear time.Examples of Auto Clear configurations:
Tier 3 Engine ECM (C15, C18, C27 & C32) is configured to delete logged DTCs if the logged DTCs do not become active within 100 SMH. Engine ECM has memory allocated to store up to 15 logged diagnostics and 15 logged events.
Motor Grader (24M) Tier 3 Machine ECM is configured to delete logged diagnostics if the logged diagnostics do not become active within 150 SMH. Events do not auto clear. Machine ECM has memory allocated to store up