19297-ZY3-000 Honda COVER, L. RELIEF VALVE (Honda Code 6991053).

Laptop Does Not Connect
If the laptop does not connect to the DCU, ensure the following:
Check if a VPN on the laptop is active. The laptop will not connect to the DCU if a VPN is active. Deactivate the VPN on the laptop and check the connection.
Check the DHCP server on the DCU. The DHCP server must be turned on to establish a connection with the laptop. Use the following steps to enable the server.
Press and hold "Home" to bring up the menu.
Press the "Settings" option and then select "Connect to PC".
Press "Enable". Confirm that the box next to the option is checked. Select "OK".
Unplug the Ethernet cable from the laptop and plug the cable back into the appropriate slot. The laptop should connect to the DCU.New Sensor Not Appearing on the DCU
In the DCU "Troubleshooting" screens, verify that the newly installed sensor is appearing in the appropriate list and showing a value. The sensor should appear under the "Voltage Sensor" troubleshooting menu.If the sensor is not displayed in the list, refer to the Programming Guide, LEBM0063, "Cat A&P Controls Programming Guide".SPN Displayed With No Description
If the alarm list displays an SPN number without a description, ensure the following:
Check that the DCU firmware is up-to-date. If the DCU has outdated firmware, download the latest firmware on SIS web (sisweb.cat.com).
Check if the device has an unrecognized SPN. If a device has been added to the engine or genset with an unrecognized SPN, the customer can submit a request through the Dealer Solutions Network(DSN) to add a new SPN to the DCU firmware.New DCU Configuration File Does Not Appear
If a new DCU configuration file has been loaded and does not appear after rebooting, update the firmware on the DCU. The configuration file was built on firmware that is newer than what is on the DCU.DCU Displays Different Screens or Missing Information
If the DCU displays different screens or is missing information, check the configuration file on the DCU. If the customer has a genset, the configuration file could be a prop file. The same applies to a prop engine. If a genset configuration file has been uploaded to the DCU instead of a prop file, the display will have incorrect or missing information. Use the following steps to find the configuration file on the DCU.
Illustration 1 g06034909
Finding the configuration file
From the "Menu" screen, select the "Help" option.
Select "Version Information". The configuration file will be the bottom line. Refer to Illustration 1.New J1939 Device Does Not Appear on the DCU
Check the DCU programming if a new J1939 device has been added but is not appearing on the DCU. The DCU must be programmed for each J1939 device. Refer to the Programming Guide, LEBM0063, "Cat A&P Controls Programming Guide" for information on programming the DCU.DCU Widgets Display Blank Information
If only some widgets are displaying "- - - -", ensure the following are broadcasting J1939 information
The engine ECM
The connected device will produce dashes to indicate that the device is not on the bus.
If most widgets are displaying "- - - -" and the alarm shows "J1939 Bus Disabled", do the following:
Acknowledge the alarm to reset the DCU. Recheck the widgets.Jacket Water Heater Control Does Not Work
If the engine speed is greater than 0 rpm, the jacket water heater should be off.
Ensure that the HTC Expansion Water Tank Level is closing. With a multimeter, ensure that there is 24V from X1.1.16 and X1.1.17Note: Make sure that the relays at schematic locations 5K28 and 8K9 are closed. The relays must be closed to enable the jacket water heater.Check for any damaged or disconnected wiring.The DCU Modbus Register Does Not Activate
If the DCU Modbus Register does not activate for a J1939 DM1 alarm, check the following:
There are two Modbus Registers for alarms
19xx registers only show DCU configured alarms.
50xx registers show DM1 alarms. These registers must be used to trigger DM1 alarms.
Check the installation drawings for modbus assignments if the modbus is incorrect.DCU Shows No Information on the Generator Screen
Check the following if the DCU does not show information on the generator screen:
The PAM is only powered by the generator. No information will be available if the genset is not running or generating voltage. Ensure that the genset is running.
Ensure that the PAM is connected to the panel properly if there is no information displayed on the DCU.The DCU Display Does Not Sleep
Ensure the following if the DCU display does not go to sleep in "Off" mode.
Check for active alarms. The DCU will not go into sleep mode if active alarms have not been acknowledged.
Check the DCU configuration. Ensure that the configuration has been set for sleep mode. Refer to the Programming Guide, LEBM0063, "Cat A&P Controls Programming Guide".
Check for damaged or disconnected wiring between the ECS and terminal 4 on the DCU.DCU Primary and Secondary Power Supply Alarm Diagnostics Active
The DCU will generate these alarms if power is lost on one supply and the other keeps the system running. When the DCU loses primary power, two alarms will appear. These alarms are "Primary Power Failure" and "Power Source Change". Secondary power failure results in the alarm "Secondary Power Failure".
Illustration 2 g06044354
Ensure that the panel isolation breakers are not tripped (Schematic - Primary 4F2, Secondary 4F4).
Check the power at the customer supplied power terminals. The primary and secondary power lines at X1.1:1 and X1.1:3 should have 24V (+) and X1.1:2 and X1.1:4 should have 0V (-).
Check the voltage from the ship power supply. Checking involves circuit breakers and wiring.
Check the connectors on the back of the DCU. Ensure that the connectors are pushed securely and both tabs are clicked inwards.RIO 410 Communication Error with the DCU
Check the following if the RIO 410 cannot communicate with the DCU:
Ensure that the RIO has power and is properly connected.
Ensure that each RIO has a unique address if multiple RIOs are on the bus.