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 ).

Clear the DTCs with the HDS.
Turn the ignition switch OFF, and then back ON (II).
Check for DTCs with the HDS.
Is DTC B1080 indicated?
1. YES - Go to step 4.
2. NO - Intermittent failure, check for loose or poor connections at the relay control module connector J (10P) and at under-dash fuse/relay box connector D (17P). If the connections are OK, check the battery condition (see BATTERY TEST ) and the charging system.
Check the MICU IG1 power supply No. 21 (7.5 A) fuse in the under-dash fuse/relay box.
Is the fuse OK?
1. YES - Go to step 5.
2. NO - Replace the fuse and recheck for DTCs.
Turn the ignition switch OFF,
Disconnect the underhood fuse/relay box connector J (10P), and inspect for loose or bent pins.
Reconnect the underhood fuse/relay box connector J (10P).
Turn the ignition switch ON (II).
Measure voltage between the No. 2 terminal of the underhood fuse/relay box connector J (10P) and body ground.

Fig 1: Measuring Voltage Between No. 2 Terminal Of Under-Hood Fuse/Relay Box Connector J And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?
1. YES - Go to step 10.
2. NO - Repair an open in the wire between the underhood fuse/relay box and the under-dash fuse/relay box.
Check the voltage between the No. 9 and No. 10 terminals of the underhood fuse/relay box connector J (10P) and body ground.

Fig 2: Checking Voltage Between No. 9 And No. 10 Terminals Of Under-Hood Fuse/Relay Box Connector J And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there less than 1 V?
1. YES - Faulty relay control module; replace the underhood fuse/relay box.
2. NO - Repair an open in the wires between the underhood fuse/relay box and G202. If the wires is OK, inspect G202.