Pinpoint Test M : The Left Heated Seat Is Inoperative - With Heated/Ventilated Seats

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.

WARNING: Incorrect repair techniques or actions can cause an accidental Supplemental Restraint System (SRS) deployment. Never compromise or depart from these instructions. Failure to precisely follow all instructions could result in serious personal injury from an accidental deployment.

M1 CHECK THE FCIM (FRONT CONTROLS INTERFACE MODULE) HEATED SEAT CONTROL SWITCH PID (PARAMETER IDENTIFICATION)
- Start the engine.
- Using a diagnostic scan tool, monitor the FCIM CC_SW_D_HSEATS PID while pressing and releasing the driver heated seat control switch.
Did the PID change when the driver heated seat control switch was pressed and released?

Yes GO to M2

No INSTALL a new FCIM. Refer to the appropriate Information and Entertainment Systems article for the procedure.

M2 CHECK FOR SCME (FRONT SEAT CLIMATE CONTROL MODULE) DIAGNOSTIC TROUBLE CODES (DTCS)

Ignition OFF.

Ignition ON.

Using a diagnostic scan tool, perform SCME self-test.

Are any SCME Diagnostic Trouble Codes (DTCs) present?

Yes	For DTC B1156:01, B1156:11, B1156:12, B1156:13 or B1156:1A, GO to M4For DTC B1153:4B, B1208:01, B1208:11 or B1208:15, GO to M6 For all other Diagnostic Trouble Codes (DTCs), REFER to DTC Chart: SCME .

GO to M3

M3 CHECK THE HEATED SEAT VOLTAGE SUPPLY CIRCUITS FOR AN OPEN

REFER to: Supplemental Restraint System (SRS) Depowering .

Disconnect: Driver Side Airbag In-line C3518 .

Disconnect: DSM C341B .

Ignition ON.

Measure:

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 M4

No	REPAIR the affected circuit. GO to M15

M4 CHECK THE HEATER ELEMENT POWER CIRCUIT FOR A SHORT TO VOLTAGE

REFER to: Supplemental Restraint System (SRS) Depowering .

Disconnect: Driver Side Airbag In-line C3518 (if not previously disconnected).

Disconnect: DSM C341D and C341E .

Disconnect: Left Front Seat Cushion Heater C3005 .

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3005-1	Courtesy of FORD MOTOR COMPANY	Ground

Is any voltage present?

Yes	REPAIR the circuit. GO to M15

GO to M5

M5 CHECK THE HEATER ELEMENT POWER CIRCUIT FOR AN OPEN OR SHORT TO GROUND

Ignition OFF.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3005-1	Courtesy of FORD MOTOR COMPANY	Ground

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3005-1	Courtesy of FORD MOTOR COMPANY	C341D-5
C3005-1	Courtesy of FORD MOTOR COMPANY	C341D-12

Are the resistances greater than 10, 000 ohms between the driver seat cushion heater mat and ground; and less than 3 ohms between the driver seat cushion heater mat and the DSM?

Yes

GO to M9

No	REPAIR the affected circuit. GO to M15

M6 CHECK THE HEATED SEAT TEMPERATURE SENSOR CIRCUIT FOR AN OPEN OR SHORT TO GROUND

REFER to: Supplemental Restraint System (SRS) Depowering .

Disconnect: Driver Side Airbag In-line C3518 .

Disconnect: DSM C341D and C341E .

Disconnect: Left Front Seat Cushion Heater C3005 .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3005-2	Courtesy of FORD MOTOR COMPANY	Ground

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3005-2	Courtesy of FORD MOTOR COMPANY	C341E-6

Is the resistance greater than 10, 000 ohms between the driver seat cushion heater mat and ground; and less than 3 ohms between the driver seat cushion heater mat and the DSM?

Yes

GO to M7

No	REPAIR the circuit. GO to M15

M7 CHECK THE HEATED SEAT TEMPERATURE SENSOR RETURN CIRCUIT FOR AN OPEN OR SHORT TO GROUND

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3005-3	Courtesy of FORD MOTOR COMPANY	Ground

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3005-3	Courtesy of FORD MOTOR COMPANY	C341E-1

Is the resistance greater than 10, 000 ohms between the driver seat cushion heater mat and ground; and less than 3 ohms between the driver seat cushion heater mat and the DSM?

Yes

GO to M8

No	REPAIR the open circuit or REFER to the Wiring Diagrams information to identify the possible causes of the circuit short. GO to M15

M8 CHECK THE HEATED SEAT TEMPERATURE SENSOR CIRCUIT FOR A SHORT TO VOLTAGE

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3005-2	Courtesy of FORD MOTOR COMPANY	Ground

Is any voltage present?

Yes	REPAIR the circuit. GO to M15

GO to M13

M9 CHECK THE HEATER ELEMENT GROUND CIRCUIT FOR AN OPEN

Disconnect: Left Front Seat Backrest Heater C3850 .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3850-2	Courtesy of FORD MOTOR COMPANY	C341D-15
C3850-2	Courtesy of FORD MOTOR COMPANY	C341D-16

Are the resistances less than 3 ohms?

Yes

GO to M10

No	REPAIR the circuit in question. GO to M15

M10 CHECK THE CUSHION HEATED SEAT MAT FOR AN OPEN OR SHORT TO GROUND

Measure the component side resistance between:

Positive Lead	Measurement / Action	Negative Lead
Courtesy of FORD MOTOR COMPANY C3005-1, Component Side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C3005-4, Component Side
Courtesy of FORD MOTOR COMPANY C3005-1, Component Side	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance between 0.6 and 2 ohms between pins 1 and 4; and greater than 10, 000 ohms between pin 1 and ground?

Yes

GO to M11

No	INSTALL a new driver seat cushion heater mat. GO to M15

M11 CHECK THE BACKREST HEATED SEAT MAT FOR AN OPEN OR SHORT TO GROUND

Measure the component side resistance between:

Positive Lead	Measurement / Action	Negative Lead
Courtesy of FORD MOTOR COMPANY C3850-1, Component Side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C3850-2, Component Side
Courtesy of FORD MOTOR COMPANY C3850-2, Component Side	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance between 0.6 and 2 ohms between pins 1 and 2; and greater than 10, 000 ohms between pin 2 and ground?

Yes

GO to M12

No	INSTALL a new driver seat backrest heater mat. GO to M15

M12 CHECK THE CIRCUIT BETWEEN THE CUSHION HEATER MAT AND BACKREST HEATER MAT FOR AN OPEN AND SHORT TO GROUND

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3005-4	Courtesy of FORD MOTOR COMPANY	Ground

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3005-4	Courtesy of FORD MOTOR COMPANY	C3850-1

Is the resistance greater than 10, 000 ohms between the driver seat cushion heater mat and ground; and less than 3 ohms between the driver seat cushion heater mat and the backrest heater mat?

Yes

GO to M14

No	REPAIR the circuit. GO to M15

M13 CHECK THE HEATED SEAT TEMPERATURE SENSOR FOR AN OPEN OR SHORT TO GROUND

Measure the component side resistance between:

Positive Lead	Measurement / Action	Negative Lead
Courtesy of FORD MOTOR COMPANY C3005-2, Component Side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C3005-3, Component Side
Courtesy of FORD MOTOR COMPANY C3005-2, Component Side	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance between 300 and 300, 000 ohms between pins 2 and 3; and greater than 10, 000 ohms between pin 2 and ground?

Yes

GO to M14

No	INSTALL a new driver seat cushion heater mat. GO to M15

M14 CHECK THE SCME (FRONT SEAT CLIMATE CONTROL MODULE) OPERATION

Ignition OFF.

Disconnect and inspect all of the DSM connectors.

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

Reconnect the DSM connectors. Make sure they seat and latch correctly.

NOTE: Do not reconnect Driver Side Airbag In-line C3518 at this time.

Reconnect all previously disconnected connectors.

Ignition ON.

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 SCME. Refer to: Driver Front Seat Module (DSM) .GO to M15

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. GO to M15

M15 VERIFY THE SRS (SUPPLEMENTAL RESTRAINT SYSTEM) PROVES OUT SUCCESSFULLY
- REFER to: Supplemental Restraint System (SRS) Depowering .
- Connect: Driver Side Airbag In-line C3518 .
- Connect all previously disconnected connectors.
- REFER to: Supplemental Restraint System (SRS) Repowering .
Did the SRS prove out successfully?

Yes Repair is complete. RETURN the vehicle to the customer.

No REFER to: Airbag Supplemental Restraint System (SRS) .