DTC 51-12: Motor Drive Circuit Malfunction

WARNING: This page is about a different car, the 2013 Honda Fit, 2012 Honda Fit, 2011 Honda Fit, 2010 Honda Fit, and 2009 Honda Fit. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information. (See General Troubleshooting Information ).

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Turn the ignition switch to LOCK (0), then turn it to ON (II) again.
Check for DTCs with the HDS.
Is DTC 51-12 indicated?

YES - Go to step 5.

NO - Intermittent failure, the system is OK at this time. Refer to intermittent failures troubleshooting (see INTERMITTENT FAILURES ).
Turn the ignition switch to LOCK (0).
Check the No. 58 (30 A) fuse in the under-dash fuse/relay box.
Is the fuse blown?

YES - Go to step 7.

NO - Reinstall the checked fuse, then go to step 14.
Disconnect the ABS modulator-control unit 25P connector (see step 3 ).
Check for continuity between ABS modulator-control unit 25P connector terminal No. 9 and body ground.
Is there continuity?

YES - Repair short to body ground in the wire between the No. 58 (30 A) fuse; in the under-dash fuse/relay box and the ABS modulator-control unit.

NO - Install a new No. 58 (30 A) fuse in the under-dash fuse/relay box, then go to step 9.

Fig 1: Checking Continuity Between ABS Modulator-Control Unit 25P Connector Terminal No. 9 & Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Reconnect the ABS modulator-control unit 25P connector.
Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Turn the ignition switch to LOCK (0), then back to ON (II) again.
Check for DTCs with the HDS.
Is DTC 51-12 indicated?

YES - Replace the ABS modulator-control unit (see ABS MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION ).

NO - The system is OK at this time.
Disconnect the ABS modulator-control unit 25P connector (see step 3 ).
Measure the voltage between ABS modulator-control unit 25P connector terminal No. 9 and body ground.
Is there battery voltage?

YES - Check for loose terminals in the ABS modulator-control unit 25P connector. If necessary, substitute a known-good ABS modulator-control unit (see ABS MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION ) and retest.

NO - Repair open in the wire between the No. 58 (30 A) fuse in the under-dash fuse/relay box and the ABS modulator-control unit.

Fig 2: Checking Voltage Between ABS Modulator-Control Unit 25P Connector Terminal No. 9 & Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.