HOUSING A 9G9159 - Caterpillar

diagnostics for the ECM of a system may be accessed through the operator display. Diagnostics may also be accessed through Cat® Electronic Technician (Cat ET). Troubleshooting a system may require the following media:
Service Manual
Testing and Adjusting
Electrical Schematic
Parts Manual
Operation and Maintenance ManualA simplified system schematic is included at the end of this manual. For additional details, see the machine Electrical Schematic.When the troubleshooting procedure instructs you to "Repair or replace the harness", use the machine Electrical Schematic to trace the circuit. Perform continuity checks at the harness connectors to locate harness failures. At the connectors of the components, check the ground circuit. There must be less than 5 ohms of resistance between any system ground and the frame ground. Excessive ground resistance greater than 5 ohms can cause incorrect diagnosing of problems.Inspect all connections before any component is replaced. Permanent or intermittent electrical problems can result if the connections are not clean and tight. Verify that the wires are pushed into the connectors completely and the connections are tight before other tests are made.If wire insulation is punctured, repair the damage. Seal the damaged wires with 8T-0065 RTV Silicone Sealant. Cover the sealant with two layers of 1P-0810 Tape .Failure of an electrical component may cause the failure of other components. Always attempt to correct the cause of an electrical system failure before you replace a component.When removing the harness from an ECM, use the single screw in the center of the harness connector.