Pinpoint Test M : The DACMC (Digital Audio Control Module C) Does Not Respond To The Scan Tool

WARNING: This page is about a different car, the 2018 Ford Focus. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Failure to disconnect the battery when instructed will result in false resistance readings.

M1 CHECK THE DACMC (DIGITAL AUDIO CONTROL MODULE C) VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

Ignition OFF.

Disconnect: DACMC C3521B

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3521B-8	Courtesy of FORD MOTOR COMPANY	Ground

Is the voltage greater than 11 volts?

Yes

GO to M2

No	VERIFY RJB fuse 22 (10A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the OEM ELECTRICAL WIRING DIAGRAM INTRODUCTION (EXCEPT ELECTRIC) to identify the possible causes of the circuit short.

M2 CHECK THE DACMC (DIGITAL AUDIO CONTROL MODULE C) GROUND CIRCUIT FOR AN OPEN

Ignition OFF.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3521B-1	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance less than 3 ohms?

Yes

GO to M3

No	REPAIR the circuit.

M3 CHECK THE HS-CAN (HIGH-SPEED CONTROLLER AREA NETWORK) CIRCUITS BETWEEN THE DACMC (DIGITAL AUDIO CONTROL MODULE C) AND THE DLC (DATA LINK CONNECTOR) FOR AN OPEN

Disconnect DACMC C3521A .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3521A-10	Courtesy of FORD MOTOR COMPANY	C251-6
C3521A-20	Courtesy of FORD MOTOR COMPANY	C251-14

Are the resistances less than 3 ohms?

Yes

GO to M4

No	REPAIR the circuit in question.

M4 CHECK FOR CORRECT DACMC (DIGITAL AUDIO CONTROL MODULE C) OPERATION

Ignition OFF.

Disconnect and inspect the DACMC connector and related in-line connectors.

Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary

Reconnect the DACMC connector and related in-line connectors. Make sure it seats and latches correctly.

Operate the system and determine if the concern is still present.

Is the concern still present?

Yes	CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new DACMC.

No	The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.