SHIELD AS 4539232 - Caterpillar

standard instrument cluster has a diagnostic LED and alarm. The optional instrument cluster has diagnostic display screens. Some operational symptom will be present when there is a problem with the system . On machines equipped with the standard instrument cluster, Caterpillar ET must be used in order to access any diagnostic and event information.On machines equipped with the optional instrument cluster, diagnostic and event information can be accessed either through Caterpillar ET or through the instrument cluster.Troubleshooting the ECM may require additional information from the machine Service Manual. The following items may be required.
Electrical System Schematic
Parts Manual
Operation and Maintenance ManualThe diagnostics for the ECM can be accessed through one of the following tools: the Operator Monitoring System and Cat® Electronic Technician (Cat ET). 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:
Operation and Maintenance Manual , SEBU8691, "272/299D SSL/CTL OMM"
Operation and Maintenance Manual , SEBU9084, "236/242/246/262/257/259/272/277/279/287/289/297/299D SSL/MTL/CTL OMM"
Systems Operation, UENR2679, "272D SSL/299D CTL MONITORING SYSTEM"
Electrical Schematic, UENR2335, "272D SKID STEER LOADER AND 299D COMPACT TRACK LOADER ELECTRICAL SYSTEM"
Electrical Schematic , UENR3962, "236D, 242D, 262D, 246D, 257D, 277D, 287D, 259D, 279D AND 289D (LRC) SKID STEER LOADER, MULTI TERRAIN LOADER AND COMPACT TRACK LOADER ELECTRICAL SYSTEM"
Electrical Schematic , UENR3963, "236D, 242D, 262D, 246D, 257D, 277D, 287D, 259D, 279D AND 289D (HRC) SKID STEER LOADER, MULTI TERRAIN LOADER AND COMPACT TRACK LOADER ELECTRICAL SYSTEM"
Electrical Schematic, UENR3966, "272D, 272D XHP SKID STEER LOADER AND 299D, 299D XHP COMPACT TRACK LOADER ELECTRICAL SYSTEM"
Electrical Schematic, UENR5959, "272D2, 272D2 XHP, 297D2, 297D2 XHP, 299D2 AND 299D2 XHP SKID STEER LOADER ELECTRICAL SYSTEM"
Electrical Schematic , UENR6684, "232D SKID STEER LOADER, 239D AND 249D COMPACT TRACK LOADER (LRC) ELECTRICAL SYSTEM"
Electrical Schematic , UENR6685, "226D AND 232D SKID STEER LOADER, 239D AND 249D COMPACT TRACK LOADER (T4F) ELECTRICAL SYSTEM"
Hydraulic Schematic, UENR2334, "272 SKID STEER LOADER AND 299D COMPACT TRACK LOADER HYDRAULIC SYSTEM"
Hydraulic Schematic, UENR3964, "236D, 242D, 246D, 262D, 272D, 272D XHP SSL / 257D, 277D, 287D MTL/ 259D, 279D, 289D, 299D CTL"
Hydraulic Schematic, UENR4731, "236D, 242D, 262D, 246DSSL/ 257D, 277D, 287D MTL/ 259D, 279D, 289D CTL HYDRAULIC SYSTEM"
Hydraulic Schematic, UENR4732, "236D, 242D, 246D, 262D SSL/257D, 277D, 287D MTL/259D, 279D, 289D, 299D XHP CTL HYDRAULIC SYSTEM"
Hydraulic Schematic, UENR6683, "226D AND 232D SKID STEER LOADER, 239D AND 249D COMPACT TRACK LOADER HYDRAULIC SYSTEM"As a guide, a simplified system schematic is at the end of this manual. For a complete electrical system schematic, see the Electrical System Schematic in the machine Service Manual.When the troubleshooting procedure instructs you to REPAIR THE HARNESS, use the Electrical System Schematic in the machine Service Manual in order to trace the circuit. Perform continuity checks at the connectors in order to locate harness failures. At component connectors, always check the ground circuit. Less than 5 ohms of resistance is required between the connector ground contacts and frame ground. Resistance that is greater than 5 ohms can cause an incorrect diagnosis of problems. During