Pinpoint Test V : The DSM (Driver Front Seat Module) Does Not Respond To The Diagnostic Scan Tool

WARNING: This page is about a different car, the 2019 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.

Refer to OEM WIRING DIAGRAMS FOR MODULE COMMUNICATIONS NETWORK - CELL 14 for schematic and connector information. Refer to OEM WIRING DIAGRAMS FOR Climate Controlled Seats - CELL 119 for schematic and connector information. Refer to OEM WIRING DIAGRAMS FOR MEMORY SEATS - CELL 123 for schematic and connector information.
Normal Operation and Fault Conditions

The DSM communicates on the MS-CAN.

Possible Sources
- Fuse
- Wiring, terminals and connector
- DSM
Visual Inspection and Pre-checks
- Verify BJB fuses 74 (30A) and 77 (30A) (with climate controlled seats) are OK.

V1 CHECK THE DSM (DRIVER FRONT SEAT MODULE) VOLTAGE SUPPLY CIRCUITS FOR AN OPEN

Ignition OFF.

Disconnect: DSM C341B.

Ignition ON.

Measure:

All Vehicles

Positive Lead	Measurement / Action	Negative Lead
C341B-3	Courtesy of FORD MOTOR COMPANY	Ground
C341B-6	Courtesy of FORD MOTOR COMPANY	Ground

Vehicles with Climate controlled seats

Positive Lead	Measurement / Action	Negative Lead
C341B-2	Courtesy of FORD MOTOR COMPANY	Ground
C341B-5	Courtesy of FORD MOTOR COMPANY	Ground

Are the voltages greater than 11 volts?

Yes

GO to V2

No	VERIFY BJB fuse 74 (30A) or 77 (30A) (with climate controlled seats) is OK. If OK, REPAIR the circuit in question. If not OK, REFER to the Wiring Diagrams service information to identify the possible causes of the circuit short.

V2 CHECK THE DSM (DRIVER FRONT SEAT MODULE) GROUND CIRCUIT FOR AN OPEN

Ignition OFF.

Disconnect: DSM C341C.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C341C-3	Courtesy of FORD MOTOR COMPANY	Ground
C341C-4	Courtesy of FORD MOTOR COMPANY	Ground
C341C-5	Courtesy of FORD MOTOR COMPANY	Ground
C341C-6	Courtesy of FORD MOTOR COMPANY	Ground

Are the resistances less than 3 ohms?

Yes

GO to V3

No	REPAIR the circuit.

V3 CHECK THE MS-CAN (MEDIUM SPEED-CONTROLLER AREA NETWORK) CIRCUITS BETWEEN THE DSM (DRIVER FRONT SEAT MODULE) AND THE GWM (GATEWAY MODULE A) FOR AN OPEN

Disconnect DSM C341F.

Disconnect GWM C2431.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C341F-8	Courtesy of FORD MOTOR COMPANY	C2431-23
C341F-7	Courtesy of FORD MOTOR COMPANY	C2431-22

Are the resistances less than 3 ohms?

Yes	CONNECT the GWM. GO to V4

No	REPAIR the circuit in question.

V4 CHECK FOR CORRECT DSM (DRIVER FRONT SEAT MODULE) OPERATION

Ignition OFF.

Disconnect and inspect all the DSM 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 DSM 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 the service article instructions. If no service articles address this concern, INSTALL a new DSM. REFER to: Driver Front Seat Module (DSM) .

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.