BASE 2386710 - Caterpillar

Basic Troubleshooting Practices
Poor and Intermittent Connections
Poor connections are the most likely cause of a problem in an electrical circuit. When a problem is identified in a particular circuit, examine the wiring connections. Verify that each connection point is clean and secure. Check for frayed connections that can cause short circuits or poor continuity. Pins and sockets can become loose in the connectors. Make sure that the pins and sockets have a good connection to the wire and remain seated in the connectors. Gently pulling on the wires and wiggling the connectors is a good practice for exposing weak connection points. Weak connections and poor mounting of components can be causes of intermittent connections. Refer to the Electrical Schematic for all of the connection points in a particular circuit. Each harness connection creates an opportunity for a weak connection in a circuit.Checking Components
Components with moving parts can wear over time. You can check components by verifying the operational range. Refer to the Systems Operation section for the operational range information of a component. Components can still function properly outside of the operational range. However, the performance should be monitored and the component replaced if machine performance is limited. Prior to replacement, perform any necessary calibration procedures for a component if poor machine performance is experienced. Verify that the machine is experiencing poor performance continually before replacing the component.Check for Software Updates and Parameter Selections
New software updates can be issued to correct repeated diagnostic codes. Always ensure that a machine is operating on the current software version before proceeding with repairs. Refer to Troubleshooting, "Electronic Control Module - Flash Program" for the procedure to download current software. Machine performance is also affected by parameter selections. Verify that a machine has the correct parameter settings to match the desired machine performance.Check ECM Operation
An ECM failure is an unlikely scenario. An ECM can fail if the ECM is not grounded properly and a welder is connected to the machine. Improper software configurations are commonly misdiagnosed as ECM failures. Do not replace an ECM until the Dealer Solution Network (DSN) has been consulted. The DSN will provide additional guidance in diagnosing and performing repairs. Disconnecting a suspected component or shorting the circuit wires at the ECM can change the active status of a diagnostic code. A successful attempt to change the status of a diagnostic code is a clear indication of proper ECM operation. Some of the troubleshooting procedures provide instruction on performing this type of test. Refer to the procedure for the appropriate diagnostic code for instructions on checking the operation of the ECM.Using Service Manuals to Find Electrical Information
The diagnostic codes contain a miniature schematic at the beginning of the procedure. The miniature schematic is a condensed drawing that may not include all of the connectors in a circuit. The purpose of the miniature schematic is to provide a point of reference for the involved component and the wires in the circuit. Do not use the miniature schematic in place of