CASE-DIFF. 2K5058 - Caterpillar

Important Safety Information
Do not perform any procedures in this Troubleshooting Guide until you have read the Operation and Maintenance Manual and you understand this information. Use only proper tools and observe all precautions that pertain to the use of those tools. Failure to follow these procedures can result in personal injury. The following procedures should also be observed.Work safely. Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs.A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools in order to perform these functions properly.Safety precautions and warnings are provided in this publication and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons. Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard.Therefore, the warnings in this publication and the warnings that are on the product are not all inclusive.Overview
These engines are equipped with an electronic control system. The system consists of a computer, sensors, and software. The system performs these functions:
Control of the engine
Applications control system interface
Fault detection and reportingElectronic Control System
The Electronic Control Module (ECM) is a computer that controls the operation of the engine.The ECM contains a flash file. The flash file is the software for the ECM. The flash file contains the operating maps. The operating maps define the following characteristics of the engine:
Horsepower
Torque curves
Engine speed (rpm)Refer to Troubleshooting, "System Overview" for additional information on the electronic control system.Application Interface
The ECM interfaces with the machine via software and an electrical connector on the ECM. The software can be configured.The application control system provides inputs to the electrical connector on the ECM in order to indicate the status of switches. Correctly configure the ECM in order to interpret the inputs. The ECM provides outputs for the application control system via the electrical connector in order to control lamps, solenoids, and other devices. Correctly configure the ECM in order for the outputs to match the configuration of the application control system.Fault Detection and Reporting
The ECM monitors inputs from the sensors and inputs from the applications control system. Software in the ECM interprets the inputs. The software determines if the inputs are operating correctly. A diagnostic trouble code is activated when the software detects a problem with an input.The ECM broadcasts the codes on two data links. The data links are the Data Link and CAN data link. The electronic service tool must communicate on both data links in order to service the engine. If a fault is suspected with the Data Link, refer to Troubleshooting, "Data Link - Test".If a fault is suspected with the CAN data link, refer to Troubleshooting, "CAN Data Link - Test".The codes can be displayed on the electronic service tool and optional operator interfaces. Refer to Troubleshooting, "Diagnostic Trouble Codes" for additional