DTC B12F0

DTC B12F0 : Power control unit lost communication with electric steering lock

DTC Description	DTC
B12F0 Power control unit lost communication with electric steering lock

DTC (Power Control Unit)

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A .

Problem verification 1

-1. Clear the DTCs with the HDS.

Clear DTCs

-2. Do this procedure ten times: Press the engine start/stop switch to select the OFF (LOCK), ACCESSORY, ON, and OFF (LOCK) mode.

-3. Check for DTCs with the HDS.

DTC Description	DTC
B12F0 Power control unit lost communication with electric steering lock

Is DTC B12F0 indicated?

YES

Go to step 2.

Intermittent failure, the system is OK at this time. Check for loose or poor connections.

Open wire check (+B SMART line)

-1. Turn the vehicle to the OFF (LOCK) mode.

-2. Disconnect the following connector.

Electric steering lock 12P connector

-3. Measure the voltage between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode Electric steering lock 12P connector: disconnected
Test point 1	Electric steering lock 12P connector (female terminals) No. 3:
Test point 2	Body ground

Courtesy of HONDA, U.S.A., INC.

Is there battery voltage?

YES

The +B SMART wire is OK. Go to step 3.

Repair an open or high resistance in the wire.

Open wire check (PGND line)

-1. Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode Electric steering lock 12P connector: disconnected
Test point 1	Electric steering lock 12P connector (female terminals) No. 7:
Test point 2	Body ground

Courtesy of HONDA, U.S.A., INC.

Is there continuity?

YES

The PGND wire is OK. Go to step 4.

Repair an open or high resistance in the ground wire or poor ground (G401).

Shorted wire check (IGN TRX line)

-1. Disconnect the following connector.

Keyless access/TPMS control unit connector C (20P)

-2. Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode Electric steering lock 12P connector: disconnected Keyless access/TPMS control unit connector C (20P): disconnected
Test point 1	Electric steering lock 12P connector (female terminals) No. 6:
Test point 2	Body ground

Courtesy of HONDA, U.S.A., INC.

Is there continuity?

YES

Repair a short to ground in the wire.

The IGN TRX wire is not shorted. Go to step 5.

Open wire check (IGN TRX line)

-1. Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode Electric steering lock 12P connector: disconnected Keyless access/TPMS control unit connector C (20P): disconnected
Test point 1	Electric steering lock 12P connector (female terminals) No. 6:
Test point 2	Keyless access/TPMS control unit connector C (20P) No. 3

Courtesy of HONDA, U.S.A., INC.

Is there continuity?

YES

The IGN TRX wire is OK. Go to step 6.

Repair an open or high resistance in the wire.

Keyless access system check:
-1. Reconnect these items:
- Electric steering lock 12P connector
- Keyless access/TPMS control unit connector C (20P)
-2. With driver's power window open, turn the vehicle to the OFF (LOCK) mode.

-3. Do the 12 volt battery terminal disconnection procedure .

-4. Wait for at least 10 seconds to clear the DTCs.

-5. Do the 12 volt battery terminal reconnection procedure .

-6. Turn the vehicle to the ON mode then the OFF (LOCK) mode.

-7. Remove all the keyless remotes from inside the vehicle. Hold them outside the open driver's window, at least 20 cm (8.0 in) away from the vehicle.

-8. Close all doors, then press the engine start/stop switch.

-9. Bring all keyless remotes back inside the vehicle and close all doors.

-10. Touch the engine start/stop switch with the keyless remote. The buttons on the keyless remote should be facing you.

-11. Press the engine start/stop switch, and turn the vehicle to the ON mode.

Does the mode change to ON?

YES

Go to step 7.

NO

Go to step 8.

Problem verification 2

-1. Clear the DTCs with the HDS.

Clear DTCs

-2. Do this procedure ten times: Press the engine start/stop switch to select the OFF (LOCK), ACCESSORY, ON, and OFF (LOCK) mode.

-3. Check for DTCs with the HDS.

DTC Description	DTC
B12F0 Power control unit lost communication with electric steering lock

Is DTC B12F0 indicated?

YES

Replace the steering lock .

Intermittent failure, the system is OK at this time. Check for loose or poor connections.

Electric steering lock communication status check

-1. Select COMMUNICATION STATUS in the INSPECTION MENU with the HDS.

One-Push - KEYLESS ACCESS CONTROL UNIT - STATUS LOG

One-Push - BACKUP CONTROL UNIT - STATUS LOG

-2. Check the value of STATUS with ELECTRICAL STEERING LOCK, STATUS with KEYLESS ACCESS CONTROL UNIT, and STATUS with BACKUP CONTROL UNIT with the HDS.

	HDS Description	Value
Status with ESL	MTR CUT1 (Cont) Status	1
	MTR CUT2 (IG) Status	1
	IG1 Input State of ESL	1
	MTRCONT Status of ESL	1
	ESL Motor Status	1
	Switch D detection for Unlock Status	1
	Switch C detection for Unlock Status	1
	Switch B detection for Unlock Status	1
Status with KEYLESS ACCESS CONTROL UNIT	FOB KEY Authentication Result	1
Status with BACKUP CONTROL UNIT	FOB KEY Authentication Result	1

NOTE: The parameters are displayed only when the vehicle cannot be turned to the ON mode.

Are only Status with ELECTRICAL STEERING LOCK 1 values indicated?

YES

Replace the steering lock .

Replace the keyless access/TPMS control unit .