VSA DTC Troubleshooting: 51-12
DTC 51-12: Motor Power Source Circuit Malfunction
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.

DTC Description
DTC
Freeze Frame
51-12 Motor Power Source Circuit Malfunction
    

1.
Problem verification:

Problem verification
?1.
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

?2.
Clear the DTC with the HDS.


?3.
Turn the ignition switch to LOCK (0), then turn it to ON (II) again, or select the OFF mode, then the ON mode.

?4.
Check for DTCs with the HDS.
DTC Description
DTC
Freeze Frame
51-12 Motor Power Source Circuit Malfunction
    

Is DTC 51-12 indicated?

     
YES
     
     
     
The failure is duplicated. Go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Refer to intermittent failures troubleshooting.?
2.
Fuse check:

Fuse check
?1.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Check the following fuse.
Fuse
No. A2-7 (30 A)
Location
Under-hood fuse/relay box

Is the fuse OK?

     
YES
     
     
     
The fuse is OK. Reinstall the fuse, then go to step 5.
     
NO
     
     
     
Go to step 3.
3.
Shorted wire check (+B ABS/VSA MTR line):

Shorted wire check (+B ABS/VSA MTR line)
?1.
Disconnect the following connector.

?2.
Check for continuity between test points 1 and 2.
Test condition
IG LOCK (0) or OFF mode
 
VSA modulator-control unit 21P connector: disconnected
Test circuit
+B ABS/VSA MTR
Test point 1
VSA modulator-control unit 21P connector No. 4 (RED)
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Repair a short to body ground in the wire between the No. A2-7 (30 A) fuse in the under-hood fuse/relay box and the VSA modulator-control unit.?
     
NO
     
     
     
The +B ABS/VSA MTR wire is OK. Install a new No. A2-7 (30 A) fuse in the under-hood fuse/relay box, then go to step 4.
4.
VSA modulator-control unit check:

VSA modulator-control unit check
?1.
Reconnect the following connector.

?2.
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

?3.
Clear the DTC with the HDS.


?4.
Turn the ignition switch to LOCK (0), then turn it to ON (II) again, or select the OFF mode, then the ON mode.

?5.
Check for DTCs with the HDS.
DTC Description
DTC
Freeze Frame
51-12 Motor Power Source Circuit Malfunction
    

Is DTC 51-12 indicated?

     
YES
     
     
     
Go to step 5.
     
NO
     
     
     
The troubleshooting is complete.?
5.
Open wire check (+B ABS/VSA MTR line):

Open wire check (+B ABS/VSA MTR line)
?1.
Disconnect the following connector.

?2.
Measure the voltage between test points 1 and 2.
Test condition
IG LOCK (0) or OFF mode
 
VSA modulator-control unit 21P connector: disconnected
Test circuit
+B ABS/VSA MTR
Test point 1
VSA modulator-control unit 21P connector No. 4 (RED)
Test point 2
Body ground


Is there battery voltage?

     
YES
     
     
     
The +B ABS/VSA MTR wire is OK. Go to step 6.
     
NO
     
     
     
Repair an open in the wire between the No. A2-7 (30 A) fuse in the under-hood fuse/relay box and the VSA modulator-control unit.?
6.
VSA modulator-control unit check (update):

VSA modulator-control unit check (update)
?1.
Reconnect the following connector.

?2.
Update the VSA modulator-control unit if it does not have the latest software.

?3.
Turn the ignition switch to LOCK (0), then turn it to ON (II) again, or select the OFF mode, then the ON mode.

?4.
Check for DTCs with the HDS.
DTC Description
DTC
Freeze Frame
     

Is DTC 51-12 indicated?

     
YES
     
     
     
Check for loose terminals in the VSA modulator-control unit 21P connector. If the VSA modulator-control unit was updated and the symptom/indication is still present, replace the VSA modulator-control unit.?
     
NO
     
     
     
Troubleshooting is complete. If any other DTCs are indicated, go to the indicated DTCs troubleshooting.?