TURBOCHARGER GP 3621622 - Caterpillar

Important Safety Information
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 in order 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.Overview
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 Selective Catalyst Reduction (SCR) system
Fault detection and reportingClean Emissions Module (CEM)
The CEM contains these components:Selective Catalyst Reduction (SCR) System - The SCR system is used to reduce NOx emissions from the engine. The SCR system is installed after the DPF partial flow in the exhaust.Partial Flow DPF - The partial flow DPF helps to remove soot from the exhaust stream prior to the exhaust entering the SCR Catalyst.Fault Detection and Reporting
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 two data links. The data links are the Cat Data Link (CDL) and J1939. Caterpillar Electronic Technician (ET) must communicate on both data links in order to service the engine. If a problem is suspected with one of the data links, refer to Troubleshooting, "Data Link - Test".The codes can be displayed on Cat ET and optional operator interfaces. Refer to Troubleshooting, "Diagnostic Trouble Codes" for additional information on diagnostic trouble codes and a complete list of codes.Troubleshooting
As a reference, simplified schematics for each of the engine subsystems are included with each of the circuit tests that are in this manual. For an accurate representation of the entire electrical schematic that is for your application, refer to the Electrical System Schematic.During troubleshooting, inspect all harness connections before any component is replaced. If these connections are not clean and tight, continuous 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 may