BLOCK 5T0967 - Caterpillar

The diagnostic troubleshooting information contained in this manual is Generic by design and is not specific to any machine. Use this manual with the most current engineering schematic for your machine.The diagnostics for the Machine ECM may be accessed through the Plus+1 Service Tool for Caterpillar in combination with the Cat® Electronic Technician (Cat ET) Service Tool. The diagnostics for the Engine ECM may be accessed through the Cat® Electronic Technician (Cat ET) Service Tool. Refer to Special Instruction, REHS7696, "Software Installation Instructions of the Plus+1 Service Tool for Caterpillar" for details. Certain diagnostics for the Machine ECM and Engine ECM can alternatively be viewed through the Operator Monitoring System. In order to troubleshoot the electronic control system of the machine, additional information is required from the Service Manual of the machine. The following list contains some of the required support materials:
Operations Manual
Test and Adjust
Electrical Schematic
Hydraulic Schematic
Operation and Maintenance
Operations/Test and AdjustWhen the troubleshooting procedure instructs you to “REPAIR THE HARNESS OR REPLACE THE HARNESS”, use the Electrical System Schematic for the machine that is being serviced to trace the circuit. Perform continuity checks at the harness connectors in order to locate harness failures. At the connectors of the components, always check the ground circuit. Less than 5 ohms of resistance is required between the ground contacts of the connector and the frame ground. The power circuits of the ECM should have less than 2 ohms of resistance between the contacts of the ground connector and the frame ground. Less than 5 ohms of resistance is required for signal circuits for normal operation. Excessive ground resistance that is greater than 5 ohms can cause incorrect diagnosing of problems.During troubleshooting, inspect all connections before any component is replaced. If these connections are not clean and tight, permanent electrical problems or intermittent electrical problems can result. Check that the wires are pushed into the connectors completely. Make sure that the connections are tight before other tests are made.Failure of an electrical component can cause the failure of other components. Also, failure of an electrical component can be caused by the failure of other components. Always attempt to correct the cause of an electrical system failure before you replace a component.