DTC Troubleshooting: P16C4 (V6: A/T) - Honda Accord CR/CT 2012-2017

DTC Troubleshooting: P16C4

DTC P16C4: Engine Mount Actuator Control Power Circuit Stuck OFF

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshots, and review the general troubleshooting information.

DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
P16C4 Engine Mount Actuator Control Power Circuit Stuck OFF

Problem verification:

Problem verification

?1.	Turn the vehicle to the ON mode.

?2.	Clear the DTC with the HDS.

?3.

Check for pending or confirmed DTCs with the HDS.

DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
P16C4 ENGINE MOUNT ACTUATOR CONTROL POWER CIRCUIT STUCK OFF

Is DTC P16C4 indicated?


	YES

Go to step 2.


	NO

Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the engine mount control unit and the active control engine mount (ACM) control relay.?

Fuse check:

Fuse check

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

?2.

Check the following fuses.

Fuse	Location
No. C3 (20 A)	Under-dash sub fuse box

?3.	Inspect the No. C3 (20 A) fuse in the under-dash sub fuse box.

Is the fuse OK?


	YES

Go to step 4.


	NO

Go to step 3.

Shorted wire check (ACM RLY OUT line):

Shorted wire check (ACM RLY OUT line)

?1.

Disconnect the following connector.

Engine mount control unit 16P connector

?2.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
Test condition	Engine mount control unit 16P connector: disconnected
Test circuit	ACM RLY OUT
Test point 1	Engine mount control unit 16P connector No. 6 (YEL)
Test point 2	Body ground

Is there continuity?


	YES

Repair a short in the ACM RLY OUT wire between engine mount control unit 16P connector terminal No. 6 and active control engine mount (ACM) control relay 4P socket No. 2. Also replace the No. C3 (20 A) fuse.?


	NO

Check the active control engine mount (ACM) control relay, and replace it if needed. Also replace the No. C3 (20 A).?

Relay check:

Relay check

?1.	Test the active control engine mount (ACM) control relay in the under-dash relay holder C.

Is the relay OK?


	YES

Go to step 5.


	NO

Replace the active control engine mount (ACM) control relay.?

Open wire check (+B ACM line):

Open wire check (+B ACM line)

?1.	Turn the vehicle to the ON mode.

?2.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode
Test condition	Active control engine mount (ACM) control relay: disconnected
Test circuit	+B ACM
Test point 1	Active control engine mount (ACM) control relay 4P socket No. 1 (ORN)
Test point 2	Body ground

Is there battery voltage?


	YES

Go to step 6.


	NO

Repair an open in the +B ACM wire between the No. C3 (20 A) fuse in the under-dash sub fuse box and active control engine mount (ACM) control relay 4P socket No. 1.?

Open wire check (IG1 ACG line):

Open wire check (IG1 ACG line)

?1.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode
Test condition	Active control engine mount (ACM) control relay: disconnected
Test circuit	IG1 ACG
Test point 1	Active control engine mount (ACM) control relay 4P socket No. 3 (PNK)
Test point 2	Body ground

Is there battery voltage?


	YES

Go to step 7.


	NO

Repair an open in the IG1 ACG wire between the No. B13 (15 A) fuse in the under-dash fuse/relay box and active control engine mount (ACM) control relay 4P socket No. 3.?

Open wire check (ACM SOL RLY line):

Open wire check (ACM SOL RLY line)

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

?2.

Disconnect the following connector.

Engine mount control unit 16P connector

?3.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Engine mount control unit 16P connector: disconnected
	Active control engine mount (ACM) control relay: disconnected
Test circuit	ACM SOL RLY
Test point 1	Engine mount control unit 16P connector No. 16 (LT BLU)
Test point 2	Active control engine mount (ACM) control relay 4P socket No. 4 (LT BLU)

Is there continuity?


	YES

Go to step 8.


	NO

Repair an open in the ACM SOL RLY wire between engine mount control unit 16P connector terminal No. 16 and active control engine mount (ACM) control relay 4P socket No. 4.?

Open wire check (ACM RLY OUT line):

Open wire check (ACM RLY OUT line)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Engine mount control unit 16P connector: disconnected
	Active control engine mount (ACM) control relay: disconnected
Test circuit	ACM RLY OUT
Test point 1	Engine mount control unit 16P connector No. 6 (YEL)
Test point 2	Active control engine mount (ACM) control relay 4P socket No. 2 (YEL)

Is there continuity?


	YES

Replace the engine mount control unit.?


	NO

Repair an open in the ACM RLY OUT wire between engine mount control unit 16P connector terminal No. 6 and active control engine mount (ACM) control relay 4P socket No. 2.?