31233-ZV5-003 Honda BUSH (M) (Honda Code 3703626).

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 engine
Control of particulate emissions via the Clean Emission Module (CEM)
Applications control system interface
Fault detection and reportingElectronic Control System
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.Application Interface
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.Clean Emissions Module (CEM)
The CEM contains these components:Diesel Particulate Filter (DPF) - A DPF is installed in the exhaust system. The DPF collects soot and ash from the engine exhaust.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).Software - Software in the ECM monitors the DPF.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 Data Link and CAN data link. The electronic service tool must communicate on both data links to service the engine. If a fault is suspected with the Data Link, refer to Troubleshooting, "Data Link - Test".If a fault is suspected with the CAN data link, refer to Troubleshooting, "CAN Data Link - Test".The codes can be displayed on the electronic service tool and optional operator interfaces. Refer to Troubleshooting, "Diagnostic Trouble Codes" for additional information on diagnostic trouble codes and a complete list of codes.Troubleshooting
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 8T-0065 Silicone Sealant. Cover the sealant with two layers of 1P-0810 Electrical Tape.Troubleshooting Associated Codes
Certain systems will display multiple codes for troubleshooting. The "Associated Codes" must be used to troubleshoot the system. The codes should be viewed as separate levels of troubleshooting. For example, a "Diesel Particulate Filter Temperature Is Low" code may be generated. This main code is not the code that requires troubleshooting.The system is designed to display the codes for this separate level of troubleshooting as an "Associated Code". The "Associated Code" is the diagnostic or the event code that needs to have the troubleshooting procedure followed.