DTC 51: Motor Lock

Check the ABS MOTOR (30 A) fuse in the main under-hood fuse/relay box, and reinstall the fuse if it is OK.
Is the fuse OK?
1. YES - Go to step 2.
2. NO - Replace the fuse, and recheck.
Disconnect the ABS modulator-control unit 25P connector.
Measure the voltage between the ABS modulator-control unit 25P connector terminal No. 9 and body ground.

Fig 1: Measuring Voltage Between ABS Modulator-Control Unit 25P Connector Terminal And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?
1. YES - Go to step 4.
2. NO - Repair open in the wire between the ABS MOTOR (30 A) fuse and the ABS modulator-control unit.
Connect the ABS modulator-control unit 25P connector.
Turn the ignition switch ON (II).
Measure the voltage on terminals No. 24 and No. 25 at the ABS modulator-control unit 25P connector.

Fig 2: Measuring Voltage On Terminals At ABS Modulator-Control Unit 25P Connector
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there 0.3 V or less?
1. YES - Go to step 7.
2. NO - Check for poor connection between the ABS modulator-control unit 25P connector and body ground G303.
Clear the DTC (see HOW TO CLEAR DTCS ).
Test-drive the vehicle at 6 mph (10 km/h) or more.
Does the ABS indicator come on, and is DTC 51 indicated?
1. YES - Check for loose terminals at the ABS modulator-control unit 25P connector. If connections are good, replace the ABS modulator-control unit.
2. NO - The system is OK at this time.