Pinpoint Test Ab : The SCMB (Passenger Front Seat Module) Does Not Respond To The Diagnostic Scan Tool

WARNING: This page is about a different car, the 2020 Lincoln Corsair. However, it is still accessible from the selected car via links, so may be relevant.

Refer to MODULE COMMUNICATIONS NETWORK for schematic and connector information. Refer to POWER SEATS for schematic and connector information.
Normal Operation and Fault Conditions

The SCMB communicates on the MS-CAN.

Possible Sources
- Fuse
- Wiring, terminals and connector
- SCMB
Visual Inspection and Pre-checks
- Verify BJB fuse 31 (30A) is OK.

AB1 CHECK THE SCMB (PASSENGER FRONT SEAT MODULE) VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

Ignition OFF.

Disconnect: SCMB C342A.

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C342A-2	Courtesy of FORD MOTOR COMPANY	Ground

Is the voltage greater than 11 volts?

Yes

GO to AB2

No	VERIFY BJB fuse 31 (30A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the OEM ELECTRICAL WIRING DIAGRAM INTRODUCTION to identify the possible causes of the circuit short.

AB2 CHECK THE SCMB (PASSENGER FRONT SEAT MODULE) GROUND CIRCUIT FOR AN OPEN

Ignition OFF.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C342A-5	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance less than 3 ohms?

Yes

GO to AB3

No	REPAIR the circuit.

AB3 CHECK THE MS-CAN (MEDIUM SPEED-CONTROLLER AREA NETWORK) CIRCUITS BETWEEN THE SCMB (PASSENGER FRONT SEAT MODULE) AND THE GWM (GATEWAY MODULE A) FOR AN OPEN

Disconnect: GWM C2431.

Disconnect SCMB C342D.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C342D-5	Courtesy of FORD MOTOR COMPANY	C2431-23
C342D-15	Courtesy of FORD MOTOR COMPANY	C2431-22

Are the resistances less than 3 ohms?

Yes

GO to AB4

No	REPAIR the circuit in question.

AB4 CHECK FOR CORRECT SCMB (PASSENGER FRONT SEAT MODULE) OPERATION

Ignition OFF.

Disconnect and inspect all the SCMB 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 SCMB 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, 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 SCMB. 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.