Pinpoint Test O : DTC B1154:4B

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.

O1 CHECK THE SCME (FRONT SEAT CLIMATE CONTROL MODULE) FOR ON-DEMAND DIAGNOSTIC TROUBLE CODES (DTCS)
- Start the vehicle and set the driver seat to HIGH heat.
- Using a diagnostic scan tool, perform the SCME self-test.
Was DTC B1154:4B retrieved on-demand during the self-test?

Yes GO to O2

No GO to O5

O2 CHECK THE DRIVER SEAT BACKREST BLOWER MOTOR THERMISTOR CIRCUITS FOR A SHORT TO GROUND

WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.

Ignition OFF.

Disconnect: Driver Side Airbag In-line C3368 .

Disconnect: DSM C341E .

Disconnect: Driver Backrest Blower Motor C3034 .

Disconnect: Driver Cushion Blower Motor C3035 .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C341E-5	Courtesy of FORD MOTOR COMPANY	Ground
C341E-1	Courtesy of FORD MOTOR COMPANY	Ground

Are the resistances greater than 10, 000 ohms?

Yes

GO to O3

No	REPAIR the affected circuit. GO to O22

O3 CHECK THE DRIVER SEAT BACKREST BLOWER MOTOR THERMISTOR AND WIRING

Connect: Driver Backrest Blower Motor C3034 .

Connect: Driver Cushion Blower Motor C3035 .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C341E-5	Courtesy of FORD MOTOR COMPANY	C341E-1

Compare the measured resistance value with the following table:

Ambient Temperature	Resistance
0-10 ° C (32-50 ° F)	2, 782-1, 663 ohms
10-20 ° C (50-68 ° F)	1, 837-1, 140 ohms
20-30 ° C (68-86 ° F)	1, 260-806 ohms
30-40 ° C (86-104 ° F)	893-570 ohms
40-50 ° C (104-122 ° F)	630-428 ohms

Is the resistance within the limits indicated?

Yes

GO to O18

GO to O4

O4 CHECK THE DRIVER SEAT BACKREST BLOWER MOTOR THERMISTOR

Disconnect: Driver Backrest Blower Motor C3034 .

Measure the component side resistance between:

Positive Lead	Measurement / Action	Negative Lead
Courtesy of FORD MOTOR COMPANY C3034-5, Component Side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C3034-8, Component Side

Compare the measured resistance value with the following table:

Ambient Temperature	Resistance
0-10 ° C (32-50 ° F)	2, 782-1, 663 ohms
10-20 ° C (50-68 ° F)	1, 837-1, 140 ohms
20-30 ° C (68-86 ° F)	1, 260-806 ohms
30-40 ° C (86-104 ° F)	893-570 ohms
40-50 ° C (104-122 ° F)	630-428 ohms

Is the resistance within the limits indicated?

Yes	REPAIR circuit CHS14 (GN) or CHS29 (WH/BU)/ RHS05 (YE/VT) for an open or high resistance. GO to O22

No	INSTALL a new driver seat backrest blower motor. REFER to: Front Seat Backrest Blower Motor . GO to O22

O5 CONFIRM THE FAULT WHILE MONITORING THE SCME (FRONT SEAT CLIMATE CONTROL MODULE) SEAT BACK TEMPERATURE - DRIVER (SEAT_BK_TMP_D) AND SEAT CUSHION TEMPERATURE - DRIVER (SEAT_CSH_TMP_D) PARAMETER IDENTIFICATIONS (PIDS)

Set the passenger seat to OFF.

Using a diagnostic scan tool, clear the SCME Diagnostic Trouble Codes (DTCs).

Using a diagnostic scan tool, monitor the SCME SEAT_BK_TMP_D and SEAT_CSH_TMP_D.

NOTE: A crushed seat backrest foam pad may be the cause of the fault making it necessary to occupy the seat to recreate and identify the fault.

Attempt to recreate the fault. Start the vehicle and set the driver seat to HIGH heat for at least 15 minutes while occupying the seat.

Do the Parameter Identifications (PIDs) increase incrementally (gradually) and stay within 15 ° C (27 ° F) of each other?

Yes	The fault is not present at this time. The fault may have been set due to a past concern, incorrect use of the climate controlled seat system by repeated switching between heat and cool modes or due to excessive passenger compartment temperature.

If the SEAT_BK_TMP_D PID increases incrementally and is greater than 15 ° C (27 ° F) difference from the SEAT_CSH_TMP_D PID, GO to O6If the SEAT_BK_TMP_D PID increases quickly (temperature "jumps" and does not increase incrementally) and is greater than 15 ° C (27 ° F) from the SEAT_CSH_TMP_D PID, GO to O16

O6 COMPARE OPERATION OF THE DRIVER AND PASSENGER SEATS

With the engine running, set both front seats to HIGH cool.

Note the airflow exhausting from the driver seat backrest blower motor and compare it to the airflow exhausting from the passenger seat backrest blower motor.

Carry out a wiggle test of the wire harnesses between the DSM and the driver seat backrest blower motor while monitoring blower operation. The blower should operate consistently and not change speeds.

Is the airflow exhausting from the driver seat backrest blower motor comparable to the airflow exhausting from the passenger seat backrest blower motor with no change in operation when carrying out the wiggle test?

Yes

GO to O7

If the airflow exhausting from the driver seat backrest blower motor is not comparable to the airflow exhausting from the passenger seat backrest blower motor, GO to O8
If the driver seat backrest blower motor operation changed while carrying out the wiggle test, IDENTIFY and REPAIR the wiring fault.

O7 COMPARE OPERATION OF THE DRIVER AND PASSENGER SEATS WHILE OCCUPIED
- Note the airflow exhausting from the driver seat backrest blower motor with the driver seat occupied and compare it to the airflow exhausting from the passenger seat backrest blower motor with the passenger seat occupied.
Is the airflow exhausting from the driver seat backrest blower motor comparable to the airflow exhausting from the passenger seat backrest blower motor?

Yes GO to O16

No INSTALL a new driver seat backrest foam pad.

O8 CHECK THE DRIVER SEAT BACKREST BLOWER FOR AN OBSTRUCTION OR RESTRICTED FILTER
- Ignition OFF.
- Inspect the blower of the driver seat backrest blower motor assembly for an obstruction or for a restricted filter.
Is the blower obstructed or the filter restricted?

Yes REMOVE the obstruction or INSTALL a new seat backrest blower motor. REFER to: Front Seat Backrest Blower Motor .

No GO to O9

O9 CHECK THE DRIVER SEAT BACKREST BLOWER SPEED CONTROL CIRCUIT FOR AN OPEN

WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.

Ignition OFF.

Disconnect: Driver Side Airbag In-line C3368 .

Disconnect: DSM C341E .

Disconnect: Driver Backrest Blower Motor C3034 .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C341E-10	Courtesy of FORD MOTOR COMPANY	C3034-7

Is the resistance less than 3 ohms?

Yes

GO to O10

No	REPAIR the circuit. GO to O22

O10 CHECK THE DRIVER SEAT BACKREST BLOWER CIRCUIT FOR A SHORT TO VOLTAGE

Ignition OFF.

Disconnect: DSM C341D .

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C341D-9	Courtesy of FORD MOTOR COMPANY	Ground

Is any voltage present?

Yes	REPAIR the circuit. GO to O22

GO to O11

O11 CHECK THE DRIVER SEAT BACKREST BLOWER CIRCUIT FOR A SHORT TO GROUND

Ignition OFF.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C341D-4	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance greater than 10, 000 ohms?

Yes

GO to O12

No	REPAIR the circuit. GO to O22

O12 CHECK THE DRIVER SEAT BACKREST BLOWER CIRCUITS FOR AN OPEN

Measure:

Positive Lead	Measurement / Action	Negative Lead
C341D-4	Courtesy of FORD MOTOR COMPANY	C3034-3
C341D-9	Courtesy of FORD MOTOR COMPANY	C3034-4

Are the resistances less than 3 ohms?

Yes

GO to O13

No	REPAIR the affected circuit. GO to O22

O13 CHECK THE DRIVER SEAT BACKREST BLOWER RESISTANCE

NOTE: The ohmmeter must be connected with the positive lead to pin 3 and the negative lead to pin 4 when measuring. Ohmmeter leads incorrectly connected results in false readings and leads to incorrect identification of components that are not faulty.

Measure the component side resistance between:

Positive Lead	Measurement / Action	Negative Lead
Courtesy of FORD MOTOR COMPANY C3034-3, Component Side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C3034-4, Component Side

Is the resistance between 4, 000 and 10, 000 ohms?

Yes

GO to O14

No	INSTALL a new driver seat backrest blower motor. REFER to: Front Seat Backrest Blower Motor . GO to O22

O14 CHECK THE DRIVER SEAT BACKREST BLOWER SPEED CONTROL RESISTANCE

NOTE: The ohmmeter must be connected with the positive lead to pin 7 and the negative lead to pin 4 when measuring. Ohmmeter leads incorrectly connected results in false readings and leads to incorrect identification of components that are not faulty.

Measure the component side resistance between:

Positive Lead	Measurement / Action	Negative Lead
Courtesy of FORD MOTOR COMPANY C3034-7, Component Side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C3034-4, Component Side

Is the resistance between 240K and 400K ohms?

Yes

GO to O15

No	INSTALL a new driver seat backrest blower motor. REFER to: Front Seat Backrest Blower Motor . GO to O22

O15 CHECK THE DRIVER SEAT BACKREST BLOWER MOTOR INSTALLATION AND FOR CRUSHED SEAT BACKREST
- Ignition OFF.
- Remove the driver seat backrest cover. REFER to: Front Seat Backrest Cover .
- Inspect the driver seat backrest for the following:
  - Blower motor correctly installed
  - Backrest foam pad crushed or restricted
Is the driver seat backrest blower motor correctly installed and are there no signs of damage to the foam pad?

Yes INSTALL the driver seat backrest cover and seat. GO to O18

No Correctly INSTALL the driver seat backrest blower motor or INSTALL a new driver seat backrest foam pad. GO to O22

O16 CHECK THE DRIVER SEAT BACKREST BLOWER MOTOR THERMISTOR AND WIRING

WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.

Ignition OFF.

Disconnect: Driver Side Airbag In-line C3368 .

Disconnect: DSM C341E .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C341E-5	Courtesy of FORD MOTOR COMPANY	C341E-1

Compare the measured resistance value with the following table:

Ambient Temperature	Resistance
0-10 ° C (32-50 ° F)	2, 782-1, 663 ohms
10-20 ° C (50-68 ° F)	1, 837-1, 140 ohms
20-30 ° C (68-86 ° F)	1, 260-806 ohms
30-40 ° C (86-104 ° F)	893-570 ohms
40-50 ° C (104-122 ° F)	630-428 ohms

Is the resistance within the limits indicated?

Yes

GO to O18

GO to O17

O17 CHECK THE DRIVER SEAT BACKREST BLOWER MOTOR THERMISTOR

Measure the component side resistance between:

Positive Lead	Measurement / Action	Negative Lead
Courtesy of FORD MOTOR COMPANY C3034-5, Component Side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C3034-8, Component Side

Compare the measured resistance value with the following table:

Ambient Temperature	Resistance
0-10 ° C (32-50 ° F)	2, 782-1, 663 ohms
10-20 ° C (50-68 ° F)	1, 837-1, 140 ohms
20-30 ° C (68-86 ° F)	1, 260-806 ohms
30-40 ° C (86-104 ° F)	893-570 ohms
40-50 ° C (104-122 ° F)	630-428 ohms

Is the resistance within the limits indicated?

Yes	REPAIR circuit CHS14 (GN) or CHS29 (WH/BU)/ RHS05 (YE/VT) for an open or high resistance. GO to O22

No	INSTALL a new driver seat backrest blower motor. REFER to: Front Seat Backrest Blower Motor . GO to O22

O18 CHECK THE DRIVER SEAT BACKREST BLOWER MOTOR HEATING/COOLING CIRCUITRY CURRENT DRAW
- Connect all DSM, blower motor and body harness-to-seat harness connectors.
- NOTE: It may be necessary to open the seat wire harness conduit to allow placing the inductive current probe around the circuit as described in the following step. Care must be taken when opening up the wire harness so as not to damage any wiring or connectors. Do not damage any wiring or induce stress on any wiring or connectors. Close up the wire harness once repairs to the seat are complete.
  
  NOTE: Use a commercially available inductive current probe (such as Electronic Specialties Current Probe/Multimeter 685 or a Fluke I410 [used with a digital multimeter]) or the low current probe from the VMM available for use with IDS. If these are unavailable, the inductive current probe feature from a battery tester may be substituted.
  
  Place an inductive current probe around circuit CHS01 (GY/VT) near DSM C341D-5 and monitor the current draw.
- Start the engine and set the driver seat to HIGH heat.
Is the current draw less than 11 amps?

Yes GO to O19

No INSTALL a new driver seat backrest blower motor. REFER to: Front Seat Backrest Blower Motor . GO to O22

O19 CHECK RESISTANCE OF THE DRIVER SEAT BACKREST BLOWER MOTOR AND WIRING

Ignition OFF.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C341D-5	Courtesy of FORD MOTOR COMPANY	C341D-15

Are the resistances between 0.9 and 10 ohms?

Yes

GO to O21

GO to O20

O20 CHECK THE RESISTANCE OF THE DRIVER SEAT BACKREST BLOWER MOTOR

Disconnect: Driver Backrest Blower Motor C3034 .

Measure the component side resistance between:

Positive Lead	Measurement / Action	Negative Lead
Courtesy of FORD MOTOR COMPANY C3034-1, Component Side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C3034-2, Component Side

Is the resistance between 0.9 and 10 ohms?

Yes	REPAIR circuit CHS01 (GY/VT) or RHS01 (WH/VT) for an open or high resistance. GO to O22

No	INSTALL a new driver seat backrest blower motor. REFER to: Front Seat Backrest Blower Motor . GO to O22

O21 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 C3368 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 Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new DSM. REFER to: Driver Front Seat Module (DSM) . GO to O22

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 O22

O22 CHECK FOR SRS (SUPPLEMENTAL RESTRAINT SYSTEM) DIAGNOSTIC TROUBLE CODES (DTCS)
- WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.
  
  Ignition OFF.
- Connect: Driver Side Airbag In-line C3368 .
- Connect all previously disconnected connectors.
- Ignition ON.
- Using a diagnostic scan tool, clear the RCM Diagnostic Trouble Codes (DTCs).
- Cycle the ignition OFF then ON.
- Using a diagnostic scan tool, perform RCM self-test.
Are any RCM Diagnostic Trouble Codes (DTCs) retrieved during self-test?

Yes REFER to: Supplemental Restraint System (Hybrid/Energi) .

No Repair is complete. RETURN the vehicle to the customer.