Pinpoint Test AK : B2730

NOTE: When taking measurements at DCSM harness connectors, do not insert the electrical probes into the female connector pins. Inserting the probes into connector pins can cause intermittent or open electrical connections after reassembly resulting in DTCs and system failure. Touching the tip of these connector pins is recommended instead.

AK1 CHECK THE DCSM FOR ON-DEMAND DTCs
- Start the vehicle and set the driver seat to HIGH heat.
- Using a diagnostic scan tool, perform DCSM self-test.
Was DTC B2730 retrieved on-demand during the self-test?

Yes GO to AK2.

No GO to AK5.

AK2 CHECK THE DRIVER SEAT BACKREST TED 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 Seat Side Air Bag C3051 and Passenger Seat Side Air Bag C339 .

Disconnect: DCSM C3265B .

Disconnect: Driver Seat Backrest TED C3034 .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3265B-9	Courtesy of FORD MOTOR COMPANY	Ground
C3265B-10	Courtesy of FORD MOTOR COMPANY	Ground

Are the resistances greater than 10, 000 ohms?

Yes	GO to AK3.
No	REPAIR the circuit(s). GO to AK22.

AK3 CHECK THE DRIVER SEAT BACKREST TED THERMISTOR AND WIRING

Connect: Driver Seat Backrest TED C3034 .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3265B-9	Courtesy of FORD MOTOR COMPANY	C3265B-10

Ambient Temperature	Resistance
0 ° C (32 ° F) to 10 ° C (50 ° F)	2, 782 to 1, 663 ohms
10 ° C (50 ° F) to 20 ° C (68 ° F)	1, 837 to 1, 140 ohms
20 ° C (68 ° F) to 30 ° C (86 ° F)	1, 250 to 806 ohms
30 ° C (86 ° F) to 40 ° C (103.9 ° F)	893 to 570 ohms
40 ° C (103.9 ° F) to 50 ° C (121.9 ° F)	630 to 428 ohms

Is the resistance within the limits indicated?

Yes	GO to AK18.
No	GO to AK4.

AK4 CHECK THE DRIVER SEAT BACKREST TED THERMISTOR

Disconnect: Driver Seat Backrest TED C3034 .

Measure the component side resistance:

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

Ambient Temperature	Resistance
0 ° C (32 ° F) to 10 ° C (50 ° F)	2, 782 to 1, 663 ohms
10 ° C (50 ° F) to 20 ° C (68 ° F)	1, 837 to 1, 140 ohms
20 ° C (68 ° F) to 30 ° C (86 ° F)	1, 250 to 806 ohms
30 ° C (86 ° F) to 40 ° C (103.9 ° F)	893 to 570 ohms
40 ° C (103.9 ° F) to 50 ° C (121.9 ° F)	630 to 428 ohms

Is the resistance within the limits indicated?

Yes	REPAIR circuit VHS35 (VT/OG)/CHS14 (GN) or RHS15 (GY/BN)/CHS29 (WH/BU) for an open or high resistance. GO to AK22.
No	INSTALL a new driver seat backrest TED. Refer to Seat Backrest Thermo-Electric Device (TED) . GO to AK22.

AK5 CONFIRM THE FAULT WHILE MONITORING THE DCSM SEAT BACK THERMAL ELECTRIC DEVICE TEMPERATURE (BK_TEMP) AND SEAT CUSHION THERMAL ELECTRIC DEVICE TEMPERATURE (CSHTEMP) PIDs

Set the driver seat to OFF.

Using a diagnostic scan tool, clear DCSM DTCs.

Using a diagnostic scan tool, view DCSM PIDs.
- Seat Cushion TED Temperature (CSHTEMP)
- Seat Back TED Temperature (BK_TEMP)

NOTE: A crushed seat backrest foam pad or a crushed climate controlled seat manifold 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.

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

Yes	Fault not present at this time. Fault may have been set due to a past failure, incorrect use of the climate controlled seat system by repeated switching between heat and cool modes or due to excessive passenger compartment temperature. CLEAR the DTCs. REPEAT the self-test.
No	If the BK_TEMP PID increases incrementally and is greater than 15 °C (27 °F) of the CSHTEMP PID, GO to AK6. If the BK_TEMP PID increases quickly (temperature "jumps" and does not increase incrementally) and is greater than 15 °C (27 °F) of the CSHTEMP PID, GO to AK16.

AK6 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 TED and compare it to the airflow exhausting from the passenger seat backrest TED.

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

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

Yes	GO to AK7.
No	If the airflow exhausting from the driver seat backrest TED is not comparable to the airflow exhausting from the passenger seat backrest TED, GO to AK8. If the driver seat backrest TED blower operation changed while carrying out the wiggle test, IDENTIFY and REPAIR the wiring fault. CLEAR the DTCs. REPEAT the self-test.

AK7 COMPARE OPERATION OF THE DRIVER AND PASSENGER SEATS WHILE OCCUPIED

Note the airflow exhausting from the driver seat backrest TED with the driver seat occupied and compare it to the airflow exhausting from the passenger seat backrest TED with the passenger seat occupied.

Is the airflow exhausting from the driver seat backrest TED comparable to the airflow exhausting from the passenger seat backrest TED ?

Yes	GO to AK16.
No	INSTALL a new driver seat backrest foam pad and/or climate controlled seat manifold. CLEAR the DTCs. REPEAT the self-test.

AK8 CHECK THE DRIVER SEAT BACKREST BLOWER FOR AN OBSTRUCTION OR RESTRICTED FILTER

Ignition OFF.

Inspect the blower of the driver seat backrest TED 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 filter. CLEAR the DTCs. REPEAT the self-test.
No	GO to AK9.

AK9 CHECK THE DRIVER SEAT BACKREST BLOWER SPEED CONTROL CIRCUIT FOR AN OPEN

Ignition OFF.

Disconnect: Driver Seat Side Air Bag C3051 and Passenger Seat Side Air Bag C339 .

Disconnect: DCSM C3265C .

Disconnect: Driver Seat Backrest TED C3034 .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3265C-12	Courtesy of FORD MOTOR COMPANY	C3034-7

Is the resistance less than 3 ohms?

Yes	GO to AK10.
No	REPAIR the circuit. GO to AK22.

AK10 CHECK THE DRIVER SEAT BACKREST BLOWER CIRCUIT FOR A SHORT TO VOLTAGE

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3265C-15	Courtesy of FORD MOTOR COMPANY	Ground

Is any voltage present?

Yes	REPAIR the circuit. GO to AK22.
No	GO to AK11.

AK11 CHECK THE DRIVER SEAT BACKREST BLOWER CIRCUIT FOR A SHORT TO GROUND

Ignition OFF.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3265C-16	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance greater than 10, 000 ohms?

Yes	GO to AK12.
No	REPAIR the circuit. GO to AK22.

AK12 CHECK THE DRIVER SEAT BACKREST BLOWER CIRCUITS FOR AN OPEN

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3265C-15	Courtesy of FORD MOTOR COMPANY	C3034-4
C3265C-16	Courtesy of FORD MOTOR COMPANY	C3034-2

Are the resistances less than 3 ohms?

Yes	GO to AK13.
No	REPAIR the circuit(s). GO to AK22.

AK13 CHECK THE DRIVER SEAT BACKREST BLOWER RESISTANCE

NOTE: The ohmmeter must be connected with the positive lead to pin 2 and the negative lead to pin 4 when measuring. Ohmmeter leads incorrectly connected can result in false readings and lead to incorrect identification of components that are not damaged.

Measure the component side resistance:

Positive Lead	Measurement / Action	Negative Lead
Driver Seat Backrest TED C3034-2, Component Side	Courtesy of FORD MOTOR COMPANY	Driver Seat Backrest TED C3034-4, Component Side

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

Yes	GO to AK14.
No	INSTALL a new driver seat backrest TED. Refer to Seat Backrest Thermo-Electric Device (TED) . GO to AK22.

AK14 CHECK THE DRIVER SEAT BACKREST BLOWER SPEED CONTROL RESISTANCE

NOTE: Connect the ohmmeter with the positive lead to pin 7 and the negative lead to pin 4 when measuring. Ohmmeter leads incorrectly connected can result in false readings and lead to incorrect identification of components that are not damaged.

Measure the component side resistance:

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

Is the resistance between 240K ohms and 420K ohms?

Yes	GO to AK15.
No	INSTALL a new driver seat backrest TED. Refer to Seat Backrest Thermo-Electric Device (TED) . GO to AK22.

AK15 CHECK THE DRIVER SEAT BACKREST TED INSTALLATION AND FOR CRUSHED SEAT BACKREST

Ignition OFF.

Remove the seat. Refer to Seat .

Remove the seat cushion cover. Refer to Seat Backrest Cover .

Inspect the driver seat backrest.
- Is the driver seat backrest TED correctly installed?
- Is the driver seat backrest seat backrest foam pad crushed or restricted?
- Is the driver seat backrest climate controlled seat manifold crushed or restricted?

Is the TED correctly installed and are the foam pad and manifold free of damage?

Yes	INSTALL the driver seat backrest cover and seat and GO to AK18.
No	CORRECTLY install the driver seat backrest TED or INSTALL a new driver seat backrest foam pad and/or climate controlled seat manifold. CONNECT the battery ground cable. GO to AK22.

AK16 CHECK THE DRIVER SEAT BACKREST TED THERMISTOR AND WIRING

Ignition OFF.

Disconnect: Driver Seat Side Air Bag C3051 and Passenger Seat Side Air Bag C339 .

Disconnect: DCSM C3265B .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3265B-9	Courtesy of FORD MOTOR COMPANY	C3265B-10

Ambient Temperature	Resistance
0 ° C (32 ° F) to 10 ° C (50 ° F)	2, 782 to 1, 663 ohms
10 ° C (50 ° F) to 20 ° C (68 ° F)	1, 837 to 1, 140 ohms
20 ° C (68 ° F) to 30 ° C (86 ° F)	1, 250 to 806 ohms
30 ° C (86 ° F) to 40 ° C (103.9 ° F)	893 to 570 ohms
40 ° C (103.9 ° F) to 50 ° C (121.9 ° F)	630 to 428 ohms

Is the resistance within the limits indicated?

Yes	GO to AK18.
No	GO to AK17.

AK17 CHECK THE DRIVER SEAT BACKREST TED THERMISTOR

Measure the component side resistance:

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

Ambient Temperature	Resistance
0 ° C (32 ° F) to 10 ° C (50 ° F)	2, 782 to 1, 663 ohms
10 ° C (50 ° F) to 20 ° C (68 ° F)	1, 837 to 1, 140 ohms
20 ° C (68 ° F) to 30 ° C (86 ° F)	1, 250 to 806 ohms
30 ° C (86 ° F) to 40 ° C (103.9 ° F)	893 to 570 ohms
40 ° C (103.9 ° F) to 50 ° C (121.9 ° F)	630 to 428 ohms

Is the resistance within the limits indicated?

Yes	REPAIR circuit VHS35 (VT/OG)/CHS14 (GN) or RHS15 (GY/BN)/CHS29 (WH/BU) for an open or high resistance. GO to AK22.
No	INSTALL a new driver seat backrest TED. Refer to Seat Backrest Thermo-Electric Device (TED) . GO to AK22.

AK18 CHECK THE DRIVER SEAT BACKREST TED HEATING/COOLING CIRCUITRY CURRENT DRAW

Connect: All DCSM, TED and body harness-to-seat harness connectors.

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 Vehicle Measurement Module available for use with IDS. If these are unavailable, the inductive current probe feature from a battery tester may be substituted.

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.

Place an inductive current probe around circuit CHS01 (GY/VT) near DCSM C3265A-J and monitor the current draw.

Start the vehicle and set the driver seat to HIGH heat.

Is the current draw less than 11 amps?

Yes	GO to AK19.
No	INSTALL a new driver seat backrest TED. Refer to Seat Backrest Thermo-Electric Device (TED) . GO to AK22.

AK19 CHECK RESISTANCE OF THE DRIVER SEAT BACKREST TED AND WIRING

Ignition OFF.

Disconnect: DCSM C3265A .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3265A-J	Courtesy of FORD MOTOR COMPANY	C3265A-K

Is the resistance between 0.9 and 10 ohms?

Yes	GO to AK21.
No	GO to AK20.

AK20 CHECK THE RESISTANCE OF THE DRIVER SEAT BACKREST TED

Disconnect: Driver Seat Backrest TED C3034 .

Measure the component side resistance:

Positive Lead	Measurement / Action	Negative Lead
Driver Seat Backrest TED C3034-1, Component Side	Courtesy of FORD MOTOR COMPANY	Driver Seat Backrest TED C3034-3, 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 AK22.
No	INSTALL a new driver seat backrest TED. Refer to Seat Backrest Thermo-Electric Device (TED) . GO to AK22.

AK21 CHECK FOR CORRECT DCSM OPERATION

Inspect the DCSM and driver seat backrest TED harness and component side connectors and the body harness-to-seat harness connectors for:

corrosion

damaged pins

pushed-out pins

Connect: All DCSM, TED and Body Harness-to-Seat Harness Connectors.

Make sure the connectors are seated correctly.

Start the engine.

Set the driver seat to OFF.

Enter the following diagnostic mode on the scan tool: Clear DTCs - DCSM.

Attempt to recreate the fault. With the engine still running set the driver seat to HIGH heat for at least 15 minutes.

Is the concern still present?

Yes	CHECK OASIS for any applicable TSBs. If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no TSBs address this concern, INSTALL a new DCSM. Refer to Dual Climate Controlled Seat Module (DCSM) . GO to AK22.
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 AK22.

AK22 CHECK FOR SRS DTCs

Ignition OFF.

Connect: Driver Seat Side Air Bag C3051 .

Connect: Passenger Seat Side Air Bag C339 .

Connect: DCSM C3265A , C3265B or C3265C (if previously disconnected).

Connect: Driver Seat Backrest TED C3034 (if previously disconnected).

Ignition ON.

Using a diagnostic scan tool, clear the RCM DTCs.

Cycle the ignition OFF then ON.

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

Are any RCM DTCs retrieved during self-test?

Yes	REFER to Supplemental Restraint System for pinpoint test direction.
No	The repair is complete. RETURN the vehicle to the customer.

Yes	GO to AK2.
No	GO to AK5.