Pinpoint Test AO: DTC B272C

WARNING: This page is about a different car, the 2010 Mercury Milan, 2010 Lincoln MKZ, and 2010 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: When taking measurements at Dual Climate Controlled Seat Module (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 Diagnostic Trouble Codes (DTCs) and system failure. Touching the tip of these connector pins is recommended instead.

NOTE: The air bag warning indicator illuminates when the correct Restraints Control Module (RCM) fuse is removed and the ignition switch is ON.

NOTE: The Supplemental Restraint System (SRS) must be fully operational and free of faults before releasing the vehicle to the customer.

AO1 CHECK FOR DCSM DTCs
- Enter the following diagnostic mode on the scan tool: Self Test - DCSM .
- Was DTC B2729 or B2730 retrieved?

Yes : For DTC B2729, Go To PINPOINT TEST AL . For DTC B2730, Go To PINPOINT TEST AS .
No : GO to AO2.

AO2 MONITOR THE TED TEMPERATURE PIDs
- Enter the following diagnostic mode on the scan tool: DataLogger - DCSM - PIDs.
  - Passenger Cushion Thermal Electric Device (TED) Temperature (PCSHTMP)
  - Passenger Back TED Temperature (PBKTMP)
  - Seat cushion thermal electric device temperature (CSHTEMP)
  - Seat back thermal electric device temperature (BK_TEMP)
    NOTE: Make sure the temperature of the climate controlled seats has stabilized before monitoring the PIDs. Not allowing stabilization can cause incorrect readings and lead to incorrect identification of components that are not faulty.
- Monitor TED temperature PIDs with the climate controlled seats OFF. Compare the PID values of the driver seat to those of the front passenger seat, this can help identify if there is a concern with the driver seat cushion or backrest PID value readings.
- Are both driver seat TED temperature PIDs within 10°C (18°F) of the ambient temperature?

Yes : GO to AO3.
No : If the driver seat cushion PID varies 10°C (18°F) or more from ambient temperature, GO to AO16.
If the driver seat backrest PID varies 10°C (18°F) or more from ambient temperature, GO to AO32.

AO3 CONFIRM THE FAULT IS IN THE SEAT CUSHION OR THE BACKREST
- Ignition OFF.
- Ignition ON.
  NOTE: A crushed seat cushion foam pad or a crushed climate controlled seat manifold may be the cause of the fault. It may be necessary to sit on the seat or place something of reasonable size and weight on the seat to recreate the fault.
  
  NOTE: If the seat shuts down before a 15-minute heat cycle has timed-out, carry out the DCSM self-test and go to the DUAL CLIMATE CONTROLLED SEAT MODULE (DCSM) DTC TABLE to continue diagnostics.
- After cycling the ignition and with the engine running, set the driver seat to high heat (3 indicators illuminated on HVAC module). Allow the seat to heat for at least 15 minutes while monitoring the TED temperature PIDs of the driver seat. If necessary, when the seat times-out after 15 minutes, set the driver seat to high heat once again.
- Do the driver seat cushion TED and backrest TED PIDs vary more than 60°C (108°F) from each other?

Yes : If the driver seat cushion PID is 60°C (108°F) hotter than the backrest PID, GO to AO5.
If the driver seat backrest PID is 60°C (108°F) hotter than the cushion PID, GO to AO20.
No : GO to AO4.

AO4 CHECK THE TEDs COOLING PERFORMANCE
- Check the TEDs cooling performance on the affected seat. Refer to COMPONENT TEST - THERMO-ELECTRIC DEVICE (TED) COOLING PERFORMANCE .
- Did the TEDs pass the component test?

Yes : The DTC may have been set by extreme cabin temperatures or excessive sunload on the seat causing the system to enter recovery mode. Occupant size and weight characteristics can also be a factor. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. If a concern cannot be found or duplicated, RETURN the vehicle to the customer.
No : CHECK the affected seat cushion or backrest for correct installation of the climate controlled seat components (TED , manifold, plenum, air ducts and foam pad). CHECK for airflow restrictions (TED inlets and outlets, TED -to-manifold or plenum connections, filters and ducts) and REPAIR as needed. CHECK for an intermittent wiring fault. REPAIR as needed. REPEAT the self-test. CLEAR the DTCs.

AO5 CHECK FOR CORRECT TED INSTALLATION AND FOR CRUSHED FOAM
- Ignition OFF.
- Remove the seat. Refer to SEAT - FRONT .
- Remove the seat cushion trim cover. Refer to SEAT CUSHION COVER - FRONT .
- Inspect the seat cushion for the following:
  - Is the cushion blower obstructed?
  - Is the blower filter restricted or plugged?
  - Is the TED correctly installed?
  - Is the seat cushion foam pad crushed or restricted?
  - Is the climate controlled seat manifold crushed or restricted?
- Is the TED correctly installed and the foam pad and manifold OK?

Yes : GO to AO6.
No : CORRECTLY install the cushion TED or INSTALL a new seat cushion foam pad and/or climate controlled seat manifold. REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. REPOWER the SRS . REFER to GENERAL PROCEDURES

AO6 CHECK THE BACKREST TED GROUND CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Position the driver seat in the vehicle and connect the seat-to-floor connectors.
- Disconnect: Driver Seat Side Air Bag Module C327.
- Disconnect: Passenger Seat Side Air Bag Module C313.
- Disconnect: DCSM C3305a.
  WARNING: Make sure no one is in the vehicle and there is nothing blocking or placed in front of any air bag module when the battery is connected. Failure to follow these instructions may result in serious personal injury in the event of an accidental deployment.
- Connect the battery ground cable. Refer to BATTERY, MOUNTING AND CABLES .
- Ignition ON.
- Measure the voltage between DCSM C3305a-K, circuit RHS01 (WH/VT), harness side and ground.
  
  Fig 1: Measuring Voltage Between DCSM C3305A-K, Circuit RHS01 (WH/VT), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is any voltage present?

Yes : REPAIR the circuit. REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to GENERAL PROCEDURES
No : GO to AO7.

AO7 CHECK THE BACKREST TED FEED CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between DCSM C3305a-J, circuit CHS01 (GY/VT), harness side and ground.
  
  Fig 2: Measuring Resistance Between DCSM C3305A-J, Circuit CHS01 (GY/VT), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10,000 ohms?

Yes : GO to AO8.
No : REPAIR the circuit. REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to GENERAL PROCEDURES

AO8 CHECK THE RESISTANCE OF THE BACKREST TED AND WIRING
- Measure the resistance between DCSM C3305a-J, circuit CHS01 (GY/VT), harness side and DCSM C3305a-K, circuit RHS01 (WH/VT), harness side.
  
  Fig 3: Checking Resistance Of Backrest TED And Wiring
  Courtesy of FORD MOTOR CO.
- Is the resistance between 0.9 and 10 ohms?

Yes : GO to AO10.
No : GO to AO9.

AO9 CHECK THE RESISTANCE OF THE BACKREST TED
- Disconnect: Backrest TED C3310.
- Measure the resistance between backrest TED C3310 pin 1 and pin 3, component side.
  
  Fig 4: Measuring Resistance Between Backrest TED C3310 Pin 1 And Pin 3, Component Side
  Courtesy of FORD MOTOR CO.
- Is the resistance between 0.9 and 10 ohms?

Yes : REPAIR the circuit(s). REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to GENERAL PROCEDURES
No : INSTALL a new backrest TED . REFER to SEAT BACKREST THERMO-ELECTRIC DEVICE . REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to GENERAL PROCEDURES

AO10 CHECK THE BLOWER MOTOR FEED AND SPEED CONTROL CIRCUITS FOR A SHORT TO VOLTAGE
- Disconnect: DCSM C3305c.
- Ignition ON.
- Measure the voltage between:
  - DCSM C3305c-16, circuit CHS03 (GN/BN), harness side and ground.
  - DCSM C3305c-11, circuit VHS18 (BN/GN), harness side and ground.
  Fig 5: Checking Blower Motor Feed And Speed Control Circuits For Short To Voltage
  Courtesy of FORD MOTOR CO.
- Is voltage present on either circuit?

Yes : GO to AO11.
No : REPAIR the circuit(s). REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to GENERAL PROCEDURES

AO11 CHECK THE BLOWER MOTOR FEED AND SPEED CONTROL CIRCUITS FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between:
  - DCSM C3305c-16, circuit CHS03 (GN/BN), harness side and ground.
  - DCSM C3305c-11, circuit VHS18 (BN/GN), harness side and ground.
  Fig 6: Checking Blower And Speed Control Circuits For Short To Ground
  Courtesy of FORD MOTOR CO.
- Are the resistances greater than 10,000 ohms?

Yes : GO to AO12.
No : REPAIR the circuit(s). REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to GENERAL PROCEDURES

AO12 CHECK THE BLOWER MOTOR AND WIRING
NOTE: The ohmmeter must be connected with the positive lead to DCSM C3305c-16, circuit CHS03 (GN/BN) and the negative lead to DCSM C3305c-15, circuit RHS03 (GY/OG) when measuring. Ohmmeter leads incorrectly connected will result in false readings and lead to incorrect identification of components that are not faulty.
- Measure the resistance between DCSM C3305c-16, circuit CHS03 (GN/BN), harness side and DCSM C3305c-15, circuit RHS03 (GY/OG), harness side.
  
  Fig 7: Checking Blower Motor And Wiring
  Courtesy of FORD MOTOR CO.
- Is the resistance between 4,000 and 10,000 ohms?

Yes : GO to AO14.
No : GO to AO13.

AO13 CHECK THE BLOWER MOTOR RESISTANCE
- Disconnect: Cushion TED C3300.
  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 will result in false readings and lead to incorrect identification of components that are not faulty.
- Measure the resistance between cushion TED C3300 pin 2 and pin 4, component side.
  
  Fig 8: Measuring Resistance Between Cushion TED C3300 Pin 2 And Pin 4, Component Side
  Courtesy of FORD MOTOR CO.
- Is the resistance between 4,000 and 10,000 ohms?

Yes : REPAIR the circuit(s). REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to GENERAL PROCEDURES
No : INSTALL a new cushion TED . REFER to SEAT CUSHION THERMO-ELECTRIC DEVICE . REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to GENERAL PROCEDURES

AO14 CHECK THE BLOWER MOTOR SPEED CONTROL AND CIRCUIT RESISTANCE
NOTE: The ohmmeter must be connected with the positive lead to C3305c-11, circuit VHS18 (BN/GN), harness side and the negative lead to C3305c-15, circuit RHS03 (GY/OG), harness side when measuring. Ohmmeter leads incorrectly connected will result in false readings and lead to incorrect identification of components that are not faulty.
- Measure the resistance between DCSM C3305c-11, circuit VHS18 (BN/GN), harness side and DCSM C3305c-15, circuit RHS03 (GY/OG), harness side.
  
  Fig 9: Checking Blower Motor Speed Control And Circuit Resistance
  Courtesy of FORD MOTOR CO.
- Is the resistance between 240 kohms and 4 megohms?

Yes : GO to AO16.
No : GO to AO15.

AO15 CHECK THE BLOWER MOTOR SPEED CONTROL RESISTANCE
- Disconnect: Cushion TED C3300.
  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 will result in false readings and lead to incorrect identification of components that are not faulty.
- Measure the resistance between cushion TED C3300 pin 7 and pin 4, component side.
  
  Fig 10: Measuring Resistance Between Cushion TED C3300 Pin 7 And Pin 4, Component Side
  Courtesy of FORD MOTOR CO.
- Is the resistance between 240 kohms and 4 megohms?

Yes : REPAIR the circuit(s). REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to GENERAL PROCEDURES
No : INSTALL a new cushion TED . REFER to SEAT CUSHION THERMO-ELECTRIC DEVICE . REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to GENERAL PROCEDURES

AO16 CHECK THE THERMISTOR FEED CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Depower the SRS. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
- Disconnect: Driver Seat Side Air Bag Module C327.
- Disconnect: Passenger Seat Side Air Bag Module C313.
- Disconnect: DCSM C3305b.
  WARNING: Make sure no one is in the vehicle and there is nothing blocking or placed in front of any air bag module when the battery is connected. Failure to follow these instructions may result in serious personal injury in the event of an accidental deployment.
- Connect the battery ground cable. Refer to BATTERY, MOUNTING AND CABLES .
- Ignition ON.
- Measure the voltage between DCSM C3305b-7, circuit VHS26 (VT), harness side and ground.
  
  Fig 11: Measuring Voltage Between DCSM C3305B-7, Circuit VHS26 (VT), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is any voltage present?

Yes : REPAIR the circuit. REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to GENERAL PROCEDURES
No : GO to AO17.

AO17 CHECK THE THERMISTOR FEED CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between DCSM C3305b-7, circuit VHS26 (VT), harness side and ground.
  
  Fig 12: Measuring Resistance Between DCSM C3305B-7, Circuit VHS26 (VT), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10,000 ohms?

Yes : GO to AO18.
No : REPAIR the circuit. REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to GENERAL PROCEDURES

AO18 CHECK THE TED THERMISTOR AND WIRING RESISTANCE AT THE DCSM

Measure the resistance between DCSM C3305b-7, circuit VHS26 (VT), harness side and DCSM C3305b-8, circuit RHS05 (YE/VT), harness side. Note the ambient temperature and compare result to the following table:

TEMPERATURE RESISTANCE REFERENCE TABLE

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 : INSTALL a new DCSM . REFER to DUAL CLIMATE CONTROLLED SEAT MODULE (DCSM) . REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to GENERAL PROCEDURES
No : GO to AO19.

Fig 13: Checking TED Thermistor And Wiring Resistance

Courtesy of FORD MOTOR CO.

AO19 CHECK THE TED THERMISTOR RESISTANCE

Disconnect: Cushion TED C3300.

Measure the resistance between cushion TED pin 5 and pin 8, component side. Note the ambient temperature and compare result to the following table:

TEMPERATURE RESISTANCE REFERENCE TABLE

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

Fig 14: Measuring Resistance Between Cushion TED Pin 5 And Pin 8, Component Side

Courtesy of FORD MOTOR CO.

Is the resistance within the limits indicated?

Yes : REPAIR the circuit(s). REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to GENERAL PROCEDURES
No : INSTALL a new cushion TED . REFER to SEAT CUSHION THERMO-ELECTRIC DEVICE . REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to GENERAL PROCEDURES

AO20 CHECK FOR CORRECT TED INSTALLATION AND FOR CRUSHED FOAM
- Ignition OFF.
- Remove the seat. Refer to SEAT - FRONT .
- Remove the seat backrest trim cover. Refer to SEAT BACKREST COVER - FRONT, WITHOUT FOLD FLAT .
- Inspect the seat backrest for the following:
  - Is the backrest blower obstructed?
  - Is the blower filter restricted or plugged?
  - Is the TED correctly installed?
  - Is the seat backrest foam pad crushed or restricted?
  - Is the climate controlled seat manifold crushed or restricted?
- Is the TED correctly installed and the foam pad and manifold OK?

Yes : GO to AO21.
No : CORRECTLY install the backrest TED or INSTALL a new seat backrest foam pad and/or climate controlled seat manifold. REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. REPOWER the SRS . REFER to GENERAL PROCEDURES

AO21 CHECK THE CUSHION TED GROUND CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Position the driver seat in the vehicle and connect the seat-to-floor connectors.
- Depower the SRS . Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
- Disconnect: Driver Seat Side Air Bag C327.
- Disconnect: Passenger Seat Side Air Bag Module C313.
- Disconnect: DCSM C3305a.
  WARNING: Make sure no one is in the vehicle and there is nothing blocking or placed in front of any air bag module when the battery is connected. Failure to follow these instructions may result in serious personal injury in the event of an accidental deployment.
- Connect the battery ground cable. Refer to BATTERY, MOUNTING AND CABLES .
- Ignition ON.
- Measure the voltage between DCSM C3305a-H, circuit RHS02 (BU/OG), harness side and ground.
  
  Fig 15: Measuring Voltage Between DCSM C3305A-H, Circuit RHS02 (BU/OG), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is any voltage present?

Yes : REPAIR the circuit. REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING
No : GO to AO22.

AO22 CHECK THE CUSHION TED FEED CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between DCSM C3305a-G, circuit CHS02 (YE/BU), harness side and ground.
  
  Fig 16: Measuring Resistance Between DCSM C3305A-G, Circuit CHS02 (YE/BU), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10,000 ohms?

Yes : GO to AO23.
No : REPAIR the circuit. REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING

AO23 CHECK THE RESISTANCE OF THE CUSHION TED AND WIRING
- Measure the resistance between DCSM C3305a-G circuit CHS02 (YE/BU), harness side and DCSM C3305a-H, circuit RHS02 (BU/OG), harness side.
  
  Fig 17: Checking Resistance Of Cushion TED And Wiring
  Courtesy of FORD MOTOR CO.
- Is the resistance between 0.9 and 10 ohms?

Yes : GO to AO25.
No : GO to AO24.

AO24 CHECK THE CUSHION TED RESISTANCE
- Disconnect: Cushion TED C3300.
- Measure the resistance between cushion TED C3300 pin 1 and pin 3, component side.
  
  Fig 18: Measuring Resistance Between Cushion TED C3300 Pin 1 And Pin 3, Component Side
  Courtesy of FORD MOTOR CO.
- Is the resistance between 0.9 and 10 ohms?

Yes : REPAIR the circuit(s). REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING
No : INSTALL a new cushion TED. REFER to SEAT CUSHION THERMO-ELECTRIC DEVICE . REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING

AO25 CHECK THE BLOWER MOTOR FEED AND SPEED CONTROL CIRCUITS FOR A SHORT TO VOLTAGE
- Disconnect: DCSM C3305c.
- Ignition ON.
- Measure the voltage between:
  - DCSM C3305c-16, circuit CHS03 (GN/BN), harness side and ground.
  - DCSM C3305c-12, circuit VHS16 (BU/GN), harness side and ground.
  Fig 19: Checking Blower Motor Feed And Speed Control Circuits For Short To Voltage
  Courtesy of FORD MOTOR CO.
- Is voltage present on either circuit?

Yes : REPAIR the circuit(s). REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING
No : GO to AO26.

AO26 CHECK THE BLOWER MOTOR AND SPEED CONTROL FEED CIRCUITS FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between:
  - DCSM C3305c-16, circuit CHS03 (GN/BN), harness side and ground.
  - DCSM C3305c-12, circuit VHS16 (BU/GN), harness side and ground.
  Fig 20: Checking Blower Motor And Speed Control Feed Circuits For Short To Ground
  Courtesy of FORD MOTOR CO.
- Are the resistances greater than 10,000 ohms?

Yes : GO to AO27.
No : REPAIR the circuit(s). REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING

AO27 CHECK THE BLOWER MOTOR AND WIRING RESISTANCE
NOTE: The ohmmeter must be connected with the positive lead to DCSM C3305c-16, circuit CHS03 (GN/BN) and the negative lead to DCSM C3305c-15, circuit RHS03 (GY/OG) when measuring. Ohmmeter leads incorrectly connected will result in false readings and lead to incorrect identification of components that are not faulty.
- Measure the resistance between DCSM C3305c-16, circuit CHS03 (GN/BN), harness side and DCSM C3305c-15, circuit RHS03 (GY/OG), harness side.
- Is the resistance between 4,000 and 10,000 ohms?

Yes : GO to AO29.
No : GO to AO28.

Fig 21: Checking Blower Motor And Wiring Resistance

Courtesy of FORD MOTOR CO.

AO28 CHECK THE BLOWER MOTOR RESISTANCE
- Disconnect: Backrest TED C3310.
  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 will result in false readings and lead to incorrect identification of components that are not faulty.
- Measure the resistance between backrest TED C3310 pin 2 and pin 4, component side.
  
  Fig 22: Measuring Resistance Between Backrest TED C3310 Pin 2 And Pin 4, Component Side
  Courtesy of FORD MOTOR CO.
- Is the resistance between 4,000 and 10,000 ohms?

Yes : REPAIR the circuit(s). REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING
No : INSTALL a new backrest TED . REFER to SEAT BACKREST THERMO-ELECTRIC DEVICE . REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING

AO29 CHECK THE BLOWER MOTOR SPEED CONTROL AND CIRCUIT RESISTANCE
NOTE: The ohmmeter must be connected with the positive lead to C3305c-12, circuit VHS16 (BU/GN), harness side and the negative lead to C3305c-15, circuit RHS03 (GY/OG), harness side when measuring. Ohmmeter leads incorrectly connected will result in false readings and lead to incorrect identification of components that are not faulty.
- Measure the resistance between DCSM C3305c-12, circuit VHS16 (BU/GN), harness side and DCSM C3305c-15, circuit RHS03 (GY/OG), harness side.
  
  Fig 23: Checking Blower Motor Speed Control And Circuit Resistance
  Courtesy of FORD MOTOR CO.
- Is the resistance between 240 kohms and 4 megohms?

Yes : GO to AO31.
No : GO to AO30.

AO30 CHECK THE BLOWER MOTOR SPEED CONTROL RESISTANCE
- Disconnect: Backrest TED C3310.
  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 will result in false readings and lead to incorrect identification of components that are not faulty.
- Measure the resistance between backrest TED C3310 pin 7 and pin 4, component side.
  
  Fig 24: Checking Blower Speed Control Resistance
  Courtesy of FORD MOTOR CO.
- Is the resistance between 240 kohms and 4 megohms?

Yes : REPAIR the circuit(s). REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING
No : INSTALL a new backrest TED. REFER to SEAT BACKREST THERMO-ELECTRIC DEVICE . REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING

AO31 CHECK THE THERMISTOR FEED CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: DCSM C3305b.
- Ignition ON.
- Measure the voltage between DCSM C3305b-9, circuit VHS35 (VT/OG), harness side and ground.
  
  Fig 25: Measuring Voltage Between DCSM C3305B-9, Circuit VHS35 (VT/OG), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is any voltage present?

Yes : REPAIR the circuit. REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING
No : GO to AO32.

AO32 CHECK THE THERMISTOR FEED CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Depower the SRS . Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
- Disconnect: Driver Seat Side Air Bag Module C327.
- Disconnect: Passenger Seat Side Air Bag Module C313.
- Disconnect: DCSM C3305b.
- Measure the resistance between DCSM C3305b-9, circuit VHS35 (VT/OG), harness side and ground.
  
  Fig 26: Measuring Resistance Between DCSM C3305B-9, Circuit VHS35 (VT/OG), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10,000 ohms?

Yes : GO to AO33.
No : REPAIR the circuit. REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING

AO33 CHECK THE TED THERMISTOR AND WIRING RESISTANCE

Measure the resistance between DCSM C3305b-9, circuit VHS35 (VT/OG), harness side and DCSM C3305b-10, circuit RHS15 (GY/BN), harness side. Note the ambient temperature and compare result to the following table:

TEMPERATURE RESISTANCE REFERENCE TABLE

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

Fig 27: Checking TED Thermistor And Wiring Resistance

Courtesy of FORD MOTOR CO.

Is the resistance within the limits indicated?

Yes : INSTALL a new DCSM . REFER to DUAL CLIMATE CONTROLLED SEAT MODULE (DCSM) . REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING
No : GO to AO34.

AO34 CHECK THE TED THERMISTOR RESISTANCE

Disconnect: Backrest TED C3310.

Measure the resistance between backrest TED pin 5 and pin 8, component side. Note the ambient temperature and compare result to the following table:

TEMPERATURE RESISTANCE REFERENCE TABLE

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

Fig 28: Measuring Resistance Between Backrest TED Pin 5 And Pin 8, Component Side

Courtesy of FORD MOTOR CO.

Is the resistance within the limits indicated?

Yes : REPAIR the circuit(s). REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING
No : INSTALL a new backrest TED . REFER to SEAT BACKREST THERMO-ELECTRIC DEVICE . REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327. CONNECT passenger seat side air bag module C313. REPOWER the SRS . REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING