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DTC B1080: Power Supply Circuit (IG1 Line) Input Error for Relay Control Module and MICU

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).
  1. Clear the DTC with the HDS.
  2. Turn the ignition switch to LOCK (0) and then back to ON (II).
  3. Wait for at least 6 seconds.
  4. Check for DTCs with the HDS.

    Is DTC B1080 indicated? 

    YES  -Go to step 5.

    NO  -Intermittent failure, check for loose or poor connections at under-hood fuse/relay box connector J (10P) and driver's under-dash fuse/relay box connector D(17P). If the connections are OK, check the battery condition (see BATTERY TEST ) and the charging system.

  5. Check the MICU IG1 power supply No. 21 (10 A) fuse in the driver's under-dash fuse/relay box.

    Is the fuse OK? 

    YES  -Go to step 6.

    NO  -Replace the fuse, and recheck for DTCs.

  6. Turn the ignition switch to LOCK (0).
  7. Disconnect under-hood fuse/relay box connector J (10P), check for loose or poor connections. If the terminals are bent, loose or corroded, repair them as necessary and recheck the system.
  8. Reconnect under-hood fuse/relay box connector J (10P).
  9. Turn the ignition switch to ON (II).
  10. Measure the voltage between the No. 8 terminal of the under-hood fuse/relay box connector J (10P) and body ground.
    Fig 1: Measuring Voltage Between No. 8 Terminal Of Under-Hood Fuse/Relay Box Connector J (10P) And Body Ground
    G06162692Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Go to step 11.

    NO  -Open, or loose connection, in the wire between the under-hood fuse/relay box and the driver's under-dash fuse/relay box. Repair the wire, and recheck for DTCs.

  11. Measure the voltage between the No. 10 terminal of under-hood fuse/relay box connector J (10P) and body ground.
    Fig 2: Measuring Voltage Between No. 10 Terminal Of Under-Hood Fuse/Relay Box Connector J (10P) And Body Ground
    G06162693Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there less than 0.1 V? 

    YES  -Faulty relay control module; replace the under-hood fuse/relay box.

    NO  -Repair open in the wire between the under-hood fuse/relay box and G301. If the wire is OK, inspect the G301.