DTC U1283: Driver's MICU Lost Communication With Passenger's 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 to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode.
Wait for at least 6 seconds.
Check for DTCs with the HDS.
Is DTC U1283 indicated?

YES - Go to step 5.

NO - Intermittent failure, the system is OK at this time. Check for loose or poor connections between the driver's MICU and the passenger's MICU.
Measure the voltage between body ground and passenger's under-dash fuse/relay box connector A (38P) terminals No. 14 and No. 35 individually.

Fig 1: Measuring Voltage Between Body Ground And Passenger's Under-Dash Fuse/Relay Box Connector A (38P) Terminals No. 14 And No. 35 Individually
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES - Go to step 7.

NO - Go to step 6.
Check the No. 15 (10 A) fuse in the under-hood fuse/relay box and the No. 12 (7.5 A) fuse in the driver's under-dash fuse/relay box.
Are the fuses OK?

YES - Repair an open or high resistance in the No. 15 (10 A) and/or No. 12 (7.5 A) fuse circuit.

NO - Replace the fuse(s). If the fuse blows again, repair a short to ground in the No. 15(10 A) and/or No. 12 (7.5 A) fuse circuit.

Measure the voltage between body ground and passenger's under-dash fuse/relay box connector A (38P) and E (18P) terminals as shown.

Passenger's under-dash fuse/relay box connector
A36	Body ground
A37
E15

Fig 2: Measuring Voltage Between Body Ground And Passenger's Under-Dash Fuse/Relay Box Connector A (38P) Terminals

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 3: Measuring Voltage Between Body Ground And Passenger's Under-Dash Fuse/Relay Box Connector And E (18P) Terminals With Connector End View

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there less than 0.2 V?

YES - Go to step 8.

NO - Repair an open or high resistance in the ground wire or poor ground (G203), (G401), and/or (G405).

Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
Disconnect passenger's under-dash fuse/relay box connector A (38P).
Disconnect the power window master switch 37P connector.
Check for continuity between passenger's under-dash fuse/relay box connector A (38P) terminals No. 11 and No. 29 and driver's under-dash fuse/relay box connector P (20P) terminals No. 6 and No. 5 respectively.

Fig 4: Checking Continuity Between Passenger's Under-Dash Fuse/Relay Box Connector A (38P) Terminals And Driver's Under-Dash Fuse/Relay Box Connector P (20P) Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Faulty driver's MICU; replace the driver's under-dash fuse/relay box (see DRIVER'S UNDER-DASH FUSE/RELAY BOX (MICU) REMOVAL AND INSTALLATION ).

NO - Repair an open or poor connection in the B-CAN wire between the driver's MICU and the passenger's MICU.