Pinpoint Test S: The DSP (Audio Digital Signal Processing Module) Does Not Respond To The Diagnostic Scan Tool

Refer to Module Communications Network for schematic and connector information. Refer to Audio System/Navigation for schematic and connector information.
Normal Operation and Fault Conditions

The DSP communicates on the HS-CAN3.

Possible Sources
- Fuse
- Wiring, terminals and connector
- DSP
Visual Inspection and Pre-checks
- Verify BCM fuse 5 (20A) and fuse 28 (20A) are OK.

S1 CHECK THE DSP (AUDIO DIGITAL SIGNAL PROCESSING MODULE) VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

Ignition OFF.

Disconnect: DSP C4326C (mid-level) or C4452D (high-level)

Ignition ON.

Measure:

Mid-Level

Positive Lead	Measurement / Action	Negative Lead
C4326C-4	Courtesy of FORD MOTOR COMPANY	Ground
C4326C-8	Courtesy of FORD MOTOR COMPANY	Ground

High-Level

Positive Lead	Measurement / Action	Negative Lead
C4452D-6	Courtesy of FORD MOTOR COMPANY	Ground
C4452D-12	Courtesy of FORD MOTOR COMPANY	Ground

Are the voltages greater than 11 volts?

Yes

GO to S2

No	VERIFY BCM fuse 5 (20A) or fuse 28 (20A) is OK. If OK, REPAIR the circuit. If not OK, REFER to OEM Electrical Wiring Diagram Introduction to identify the possible causes of the circuit short.

S2 CHECK THE AUDIO DSP (AUDIO DIGITAL SIGNAL PROCESSING MODULE) GROUND CIRCUIT FOR AN OPEN

Ignition OFF.

Measure:

Mid-Level

Positive Lead	Measurement / Action	Negative Lead
C4326C-1	Courtesy of FORD MOTOR COMPANY	Ground
C4326C-5	Courtesy of FORD MOTOR COMPANY	Ground

High-Level

Positive Lead	Measurement / Action	Negative Lead
C4452D-3	Courtesy of FORD MOTOR COMPANY	Ground
C4452D-9	Courtesy of FORD MOTOR COMPANY	Ground

Are the resistances less than 3 ohms?

Yes

GO to S3

No	REPAIR the circuit.

S3 CHECK THE HS-CAN3 (HIGH-SPEED CONTROLLER AREA NETWORK 3) CIRCUITS BETWEEN THE AUDIO DSP (AUDIO DIGITAL SIGNAL PROCESSING MODULE) AND THE GWM (GATEWAY MODULE A) FOR AN OPEN

Disconnect: GWM C2431.

Measure:

Mid-Level

Positive Lead	Measurement / Action	Negative Lead
C4326C-2	Courtesy of FORD MOTOR COMPANY	C2431-16
C4326C-3	Courtesy of FORD MOTOR COMPANY	C2431-15

High-Level

Positive Lead	Measurement / Action	Negative Lead
C4452D-4	Courtesy of FORD MOTOR COMPANY	C2431-16
C4452D-5	Courtesy of FORD MOTOR COMPANY	C2431-15

Are the resistances less than 3 ohms?

Yes	CONNECT the GWM, GO to S4

No	REPAIR the circuit in question.

S4 CHECK FOR CORRECT AUDIO DSP (AUDIO DIGITAL SIGNAL PROCESSING MODULE) OPERATION

Ignition OFF.

Disconnect and inspect the audio DSP 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 audio DSP connectors. Make sure they seat and latch 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, GSB, SSM or FSA If a service article exists for this concern, DISCONTINUE this test and FOLLOW service article instructions. If no service articles address this concern, INSTALL a new DSP. REFER to: Audio Digital Signal Processing (DSP) Module

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.