DTC Troubleshooting: C1120-14

DTC C1120-14: Electric Parking Brake Switch Circuit Malfunction

NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description	DTC	Freeze Frame
C1120-14 Electric Parking Brake Switch Circuit Malfunction

Problem verification:

Problem verification

?1.	Turn the vehicle to the ON mode.

?2.	Clear the DTC with the HDS.

?3.	Turn the vehicle to the OFF (LOCK) mode, then to the ON mode.

?4.

Check for DTCs with the HDS.

DTC Description	DTC	Freeze Frame
C1120-14 Electric Parking Brake Switch Circuit Malfunction

Is DTC C1120-14 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. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.?

Electric parking brake switch check:

Electric parking brake switch check

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

?2.	Check the electric parking brake switch.

Is the electric parking brake switch OK?


	YES

Go to step 3.


	NO

Replace the electric parking brake/automatic brake hold switch.?

Shorted wire check (SW lines):

Shorted wire check (SW lines)

?1.

Disconnect the following connectors.

VSA modulator-control unit 46P connector

Electric parking brake/automatic brake hold switch 12P connector

?2.

Check for continuity between the following test points and body ground individually.

Test condition	Vehicle OFF (LOCK) mode
	VSA modulator-control unit 46P connector: disconnected
	Electric parking brake/automatic brake hold switch 12P connector: disconnected

Connector	Test circuit	Test point 1	Test point 2
VSA modulator-control unit 46P connector	SW1	No. 9	Body ground
	SW3	No. 24
	SW4	No. 10
	SW6	No. 25

Is there continuity?


	YES

Repair a short to body ground in the wires between the VSA modulator-control unit and the electric parking brake/automatic brake hold switch.?


	NO

The SW wires are not shorted. Go to step 4.

Open wire check (SW lines):

Open wire check (SW lines)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	VSA modulator-control unit 46P connector: disconnected
	Electric parking brake/automatic brake hold switch 12P connector: disconnected
Test circuit 1
Test point 1	VSA modulator-control unit 46P connector No. 9
Test point 2	Electric parking brake/automatic brake hold switch 12P connector (female terminals) No. 4:

Test circuit 2
Test point 1	VSA modulator-control unit 46P connector No. 24
Test point 2	Electric parking brake/automatic brake hold switch 12P connector (female terminals) No. 1:

Test circuit 3
Test point 1	VSA modulator-control unit 46P connector No. 10
Test point 2	Electric parking brake/automatic brake hold switch 12P connector (female terminals) No. 2:

Test circuit 4
Test point 1	VSA modulator-control unit 46P connector No. 25
Test point 2	Electric parking brake/automatic brake hold switch 12P connector (female terminals) No. 3:

Is there continuity?


	YES

The SW wires are OK. Check for loose terminals and poor connections in the VSA modulator-control unit 46P connector. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting. If they are OK, replace the VSA modulator-control unit.?


	NO

Repair an open in the wires between the VSA modulator-control unit and the electric parking brake/automatic brake hold switch.?