Pinpoint Test Z : The Rear Audio Control Module (RACM) Does Not Respond To The Diagnostic Scan Tool

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

Z1 CHECK THE RACM (REAR AUDIO CONTROL MODULE) VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

Ignition OFF.

Disconnect: RACM C3077 .

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3077-1	Courtesy of FORD MOTOR COMPANY	Ground

Is the voltage greater than 11 volts?

Yes

GO to Z2

No	VERIFY the BCM fuse 33 (20A) is OK. If OK, REPAIR the circuit. If not OK, Refer to the Wiring Diagram Information to identify the possible causes of the circuit short.

Z2 CHECK THE RACM (REAR AUDIO CONTROL MODULE) GROUND CIRCUIT FOR AN OPEN

Ignition OFF.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3077-8	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance less than 3 ohms?

Yes

GO to Z3

No	REPAIR the circuit.

Z3 CHECK THE HS-CAN3 (HIGH-SPEED CONTROLLER AREA NETWORK 3) CIRCUITS BETWEEN THE RACM (REAR AUDIO CONTROL MODULE) AND THE GWM (GATEWAY MODULE A) FOR AN OPEN

Disconnect GWM C2431 .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3077-6	Courtesy of FORD MOTOR COMPANY	C2431-16
C3077-5	Courtesy of FORD MOTOR COMPANY	C2431-15

Are the resistances less than 3 ohms?

Yes

GO to Z4

No	REPAIR the circuit in question.

Z4 CHECK FOR CORRECT RACM (REAR AUDIO CONTROL MODULE) OPERATION

Ignition OFF.

Disconnect and inspect all the RACM connector.

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 RACM connector. 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 service articles: TSB, General Service Bulletin (GSB), SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new RACM. REFER to: Rear Audio Control Module (RACM) .

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.