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 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.
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 reporting
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.
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 to indicate the status of switches. Correctly configure the ECM to interpret the inputs.
The ECM provides outputs for the application control system via the electrical connector 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.
The CEM contains this component:
Diesel Oxidation Catalyst (DOC) - A DOC is installed in the exhaust system. The DOC oxidizes hydrocarbons (HC), carbon monoxide (CO), odor causing compounds, and soluble organic fractions (SOF).
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 the CAN data link. The electronic service tool must communicate on the CAN data link to service the engine. If a fault is suspected with the CAN data link, refer to Troubleshooting, "CAN Data Link - Test".
Up to six codes can be displayed on the electronic service tool and optional operator interfaces. If six codes are displayed, older codes must be cleared before new codes can be seen. Refer to Troubleshooting, "Diagnostic Trouble Codes" for additional information on diagnostic trouble codes and a complete list of codes.
During troubleshooting, refer to the Electrical System Schematic for the application.
During troubleshooting, inspect all harness connections before any component is replaced. If these connections are not clean and secure, continuous electrical faults or intermittent electrical faults 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 may cause the failure of other components. Always attempt to correct the cause of an electrical failure before you replace a component. If wire insulation is punctured, repair the damage. Seal the damaged wires with a suitable silicone sealant. Cover the sealant with two layers of a suitable electrical tape.