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Home >> Mercury >> 2008 >> Milan Base, 2.3 Z, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 1394 (Seat System - Seating) >> Diagnostic Tests >> Seats >> Pinpoint Tests >> Pinpoint Test AB: DTC B272C - Driver Differential Temperature Fault >> Pinpoint Test Ab: DTC B272C - Driver Differential Temperature Fault

Pinpoint Test Ab: DTC B272C - Driver Differential Temperature Fault

WARNING: This page is about a different car, the 2009 Mercury Milan, 2009 Lincoln MKZ, and 2009 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
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.
  1. AB1 CHECK THE DCSM FOR DTCs 
    • Connect the diagnostic tool.
    • Enter the following diagnostic mode on the diagnostic tool: Self-Test/DCSM Retrieve DTCs
    • Was DTC B2729 or B2730 retrieved during the self-test or as a continuous DTC? 
    1. YES  : For DTC B2729, go to Pinpoint Test Y . For DTC B2730, go to Pinpoint Test AD .
    2. NO  : Go to  AB2.
  2. AB2 MONITOR THE DCSM TED TEMPERATURE PIDs 
    • Enter the following diagnostic mode on the diagnostic tool: DataLogger/DCSM
      • 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 the 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? 
    1. YES  : Go to  AB3.
    2. NO  : If the driver seat cushion PID varies 10°C (18°F) or more from ambient temperature, go to  AB16.

      If the driver seat backrest PID varies 10°C (18°F) or more from ambient temperature, go to  AB32.

  3. AB3 CONFIRM THE FAULT IS IN THE SEAT CUSHION OR THE BACKREST 
    • Key in OFF position.
    • Key in ON position.
    • 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 CHART  to continue diagnostics.
    • After cycling the ignition switch and with the engine running, set the driver seat to high heat (3 LEDs 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? 
    1. YES  : If the driver seat cushion PID is 60°C (108°F) hotter than the backrest PID, go to  AB5.

      If the driver seat backrest PID is 60°C (108°F) hotter than the cushion PID, go to  AB20.

    2. NO  : Go to  AB4.
  4. AB4 CHECK THE TEDs COOLING PERFORMANCE 
    1. 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.
    2. 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.
  5. AB5 CHECK THE TED INSTALLATION AND FOR A CRUSHED SEAT CUSHION 
    • Key in OFF position.
    • 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 are there no signs of damage to the foam pad and manifold? 
    1. YES  : Go to  AB6.
    2. 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 SUPPLEMENTAL RESTRAINT SYSTEM article.

  6. AB6 CHECK THE BACKREST TED- CIRCUIT FOR SHORT TO VOLTAGE 
    • Key in OFF position.
    • 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 in the General Procedures portion of SUPPLEMENTAL RESTRAINT SYSTEM article.
    • Disconnect the driver seat side air bag module C327.
    • Disconnect the 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 article.
    • Key in ON position.
    • Fig 1: Checking Backrest TED- Circuit For Short To Voltage
      GF0021413Courtesy of FORD MOTOR CO.
    • Measure the voltage between DCSM C3305a-K, circuit RHS01 (WH/VT), harness side and ground.
    • Is the voltage less than 0.5 volt? 
    1. YES  : Go to  AB7.
    2. 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 article.

  7. AB7 CHECK THE BACKREST TED+ CIRCUIT FOR SHORT TO GROUND 
    • Key in OFF position.
    • Fig 2: Checking Backrest TED+ Circuit For Short To Ground
      GF0021414Courtesy of FORD MOTOR CO.
    • Measure the resistance between DCSM C3305a-J, circuit CHS01 (GY/VT), harness side and ground.
    • Is the resistance greater than 10,000 ohms? 
    1. YES  : Go to  AB8.
    2. 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 article.

  8. AB8 CHECK RESISTANCE OF THE BACKREST TED AND WIRING 
      Fig 3: Checking Resistance Of Backrest TED And Wiring
      GF0021383Courtesy of FORD MOTOR CO.
    • Measure the resistance between DCSM C3305a-J, circuit CHS01 (GY/VT), harness side and DCSM C3305a-K, circuit RHS01 (WH/VT), harness side.
    • Is the resistance between 0.9 and 10 ohms? 
    1. YES  : Go to  AB10.
    2. NO  : Go to  AB9.
  9. AB9 CHECK RESISTANCE OF THE BACKREST TED 
    • Disconnect: Backrest TED C3310
    • Fig 4: Checking Resistance Of Backrest TED
      GF0021381Courtesy of FORD MOTOR CO.
    • Measure the resistance between backrest TED C3310 pin 1 and pin 3, component side.
    • Is the resistance between 0.9 and 10 ohms? 
    1. YES  : REPAIR the affected 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 article.

    2. 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 article.

  10. AB10 CHECK BLOWER CIRCUIT CHS03 (GN/BN) AND SPEED CONTROL CIRCUIT VHS18 (BN/GN) FOR A SHORT TO VOLTAGE 
    • Disconnect: DCSM C3305c
    • Key in ON position.
    • Fig 5: Measuring Voltage
      GF0021415Courtesy of FORD MOTOR CO.
    • Measure the voltage between DCSM C3305c-16, circuit CHS03 (GN/BN), harness side and ground and between DCSM C3305c-11, circuit VHS18 (BN/GN), harness side and ground.
    • Are the voltages less than 1 volt? 
    1. YES  : Go to  AB11.
    2. 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 article.

  11. AB11 CHECK THE BLOWER AND SPEED CONTROL CIRCUITS FOR A SHORT TO GROUND 
    • Key in OFF position.
    • Fig 6: Checking Blower & Speed Control Circuits For A Short To Ground
      GF0021416Courtesy of FORD MOTOR CO.
    • Measure the resistance between DCSM C3305c-16, circuit CHS03 (GN/BN), harness side and ground and between DCSM C3305c-11, circuit VHS18 (BN/GN), harness side and ground.
    • Are the resistances greater than 10,000 ohms? 
    1. YES  : Go to  AB12.
    2. 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 article.

  12. AB12 CHECK THE BLOWER AND WIRING 
      Fig 7: Checking Blower & Wiring
      GF0021417Courtesy of FORD MOTOR CO.
      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 6K ohms and 9K ohms? 
    1. YES  : Go to  AB14.
    2. NO  : Go to  AB13.
  13. AB13 CHECK THE BLOWER 
    • Disconnect: Cushion TED C3300
    • Fig 8: Checking Blower Resistance
      GF0021401Courtesy of FORD MOTOR CO.
      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.
    • Is the resistance between 6K ohms and 9K ohms? 
    1. YES  : REPAIR the affected 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 article.

    2. 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 article.

  14. AB14 CHECK THE BLOWER SPEED CONTROL AND CIRCUIT 
      Fig 9: Checking Blower Speed Control And Circuit
      GF0021418Courtesy of FORD MOTOR CO.
      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.
    • Is the resistance between 290K ohms and 420K ohms? 
    1. YES  : Go to  AB16.
    2. NO  : Go to  AB15.
  15. AB15 CHECK THE BLOWER SPEED CONTROL 
    • Disconnect: Cushion TED C3300
    • Fig 10: Checking Blower Speed Control
      GF0021397Courtesy of FORD MOTOR CO.
      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.
    • Is the resistance between 290K ohms and 420K ohms? 
    1. YES  : REPAIR the affected 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 article.

    2. 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 article.

  16. AB16 CHECK THE THERMISTOR CIRCUIT FOR A SHORT TO VOLTAGE 
    • Key in OFF position.
    • Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the General Procedures portion of SUPPLEMENTAL RESTRAINT SYSTEM article.
    • Disconnect the driver seat side air bag module C327.
    • Disconnect the 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 article.
    • Key in ON position.
    • Fig 11: Checking Thermistor Circuit For A Short To Voltage
      GF0021420Courtesy of FORD MOTOR CO.
    • Measure the voltage between DCSM C3305b-7, circuit VHS26 (VT), harness side and ground.
    • Is the voltage less than 0.5 volt? 
    1. YES  : Go to  AB17.
    2. 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 article.

  17. AB17 CHECK THE THERMISTOR CIRCUIT FOR A SHORT TO GROUND 
    • Key in OFF position.
    • Fig 12: Checking Thermistor Circuit For A Short To Ground
      GF0021421Courtesy of FORD MOTOR CO.
    • Measure the resistance between DCSM C3305b-7, circuit VHS26 (VT), harness side and ground.
    • Is the resistance greater than 10,000 ohms? 
    1. YES  : Go to  AB18.
    2. 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 article.

  18. AB18 CHECK THE THERMISTOR AND WIRING 
      Fig 13: Checking Thermistor & Wiring
      GF0021422Courtesy of FORD MOTOR CO.
    • 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 refer to the following 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? 
    1. YES  : INSTALL a new DCSM and CARRY OUT programmable module installation (PMI). 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 article.

    2. NO  : Go to  AB19.
  19. AB19 CHECK THE THERMISTOR 
    • Disconnect: Cushion TED C3300
    • Fig 14: Checking Blower Speed Control
      GF0021397Courtesy of FORD MOTOR CO.
    • Measure the resistance between cushion TED pin 5 and pin 8, component side. Note the ambient temperature and refer to the following 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? 
    1. YES  : REPAIR the affected 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 article.

    2. 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 article.

  20. AB20 CHECK THE TED INSTALLATION AND FOR A CRUSHED SEAT BACKREST 
    • Key in OFF position.
    • 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 are there no signs of damage to the foam pad and manifold? 
    1. YES  : Go to  AB21.
    2. 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 SUPPLEMENTAL RESTRAINT SYSTEM article.

  21. AB21 CHECK CUSHION TED CIRCUIT RHS02 (BU/OG) FOR A SHORT TO VOLTAGE 
    • Key in OFF position.
    • 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 in the General Procedures portion of SUPPLEMENTAL RESTRAINT SYSTEM article.
    • Disconnect the driver seat side air bag module C327.
    • Disconnect the 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 article.
    • Key in ON position.
    • Fig 15: Measuring Voltage
      GF0021423Courtesy of FORD MOTOR CO.
    • Measure the voltage between DCSM C3305a-H, circuit RHS02 (BU/OG), harness side and ground.
    • Is the voltage less than 0.5 volt? 
    1. YES  : Go to  AB22.
    2. 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 article.

  22. AB22 CHECK THE CUSHION TED+ CIRCUIT FOR SHORT TO GROUND 
    • Key in OFF position.
    • Fig 16: Checking Cushion TED+ Circuit For Short To Ground
      GF0021424Courtesy of FORD MOTOR CO.
    • Measure the resistance between DCSM C3305a-G, circuit CHS02 (YE/BU), harness side and ground.
    • Is the resistance greater than 10,000 ohms? 
    1. YES  : Go to  AB23.
    2. 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 article.

  23. AB23 CHECK THE RESISTANCE OF THE CUSHION TED AND WIRING 
      Fig 17: Checking Resistance Of Cushion TED & Wiring
      GF0021425Courtesy of FORD MOTOR CO.
    • Measure the resistance between DCSM C3305a-G circuit CHS02 (YE/BU), harness side and DCSM C3305a-H, circuit RHS02 (BU/OG), harness side.
    • Is the resistance between 0.9 and 10 ohms? 
    1. YES  : Go to  AB25.
    2. NO  : Go to  AB24.
  24. AB24 CHECK THE RESISTANCE OF THE CUSHION TED 
    • Disconnect: Cushion TED C3300
    • Fig 18: Checking Resistance Of Cushion TED
      GF0021381Courtesy of FORD MOTOR CO.
    • Measure the resistance between cushion TED C3300 pin 1 and pin 3, component side.
    • Is the resistance between 0.9 and 10 ohms? 
    1. 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 article.

    2. 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 article.

  25. AB25 CHECK BLOWER CIRCUIT CHS03 (GN/BN) AND SPEED CONTROL CIRCUIT VHS16 (BU/GN) FOR A SHORT TO VOLTAGE 
    • Disconnect: DCSM C3305c
    • Key in ON position.
    • Fig 19: Measuring Voltage
      GF0021426Courtesy of FORD MOTOR CO.
    • Measure the voltage between DCSM C3305c-16, circuit CHS03 (GN/BN), harness side and ground and between DCSM C3305c-12, circuit VHS16 (BU/GN), harness side and ground.
    • Are the voltages less than 1 volt? 
    1. YES  : Go to  AB26.
    2. 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 article.

  26. AB26 CHECK THE BLOWER AND SPEED CONTROL CIRCUITS FOR A SHORT TO GROUND 
    • Key in OFF position.
    • Fig 20: Checking Blower And Speed Control Circuits For A Short To Ground
      GF0021427Courtesy of FORD MOTOR CO.
    • Measure the resistance between DCSM C3305c-16, circuit CHS03 (GN/BN), harness side and ground and between DCSM C3305c-12, circuit VHS16 (BU/GN), harness side and ground.
    • Are the resistances greater than 10,000 ohms? 
    1. YES  : Go to  AB27.
    2. 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 article.

  27. AB27 CHECK THE BLOWER AND WIRING 
      Fig 21: Checking Blower & Wiring
      GF0021417Courtesy of FORD MOTOR CO.
      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 6K ohms and 9K ohms? 
    1. YES  : Go to  AB29.
    2. NO  : Go to  AB28.
  28. AB28 CHECK THE BLOWER 
    • Disconnect: Backrest TED C3310
    • Fig 22: Checking Blower Resistance
      GF0021401Courtesy of FORD MOTOR CO.
      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.
    • Is the resistance between 6K ohms and 9K ohms? 
    1. YES  : REPAIR the affected 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 article.

    2. 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 article.

  29. AB29 CHECK THE BLOWER SPEED CONTROL AND CIRCUIT 
      Fig 23: Checking Blower Speed Control And Circuit
      GF0021428Courtesy of FORD MOTOR CO.
      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.
    • Is the resistance between 290K ohms and 420K ohms? 
    1. YES  : Go to  AB31.
    2. NO  : Go to  AB30.
  30. AB30 CHECK THE BLOWER SPEED CONTROL 
    • Disconnect: Backrest TED C3310
    • Fig 24: Checking Blower Speed Control
      GF0021402Courtesy of FORD MOTOR CO.
      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.
    • Is the resistance between 290K ohms and 420K ohms? 
    1. YES  : REPAIR the affected 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 article.

    2. 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 article.

  31. AB31 CHECK THE THERMISTOR CIRCUIT FOR A SHORT TO VOLTAGE 
    • Disconnect: DCSM C3305b
    • Key in ON position.
    • Fig 25: Checking Thermistor Circuit For A Short To Voltage
      GF0021429Courtesy of FORD MOTOR CO.
    • Measure the voltage between DCSM C3305b-9, circuit VHS35 (VT/OG), harness side and ground.
    • Is the voltage less than 0.5 volt? 
    1. YES  : Go to  AB32.
    2. 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 article.

  32. AB32 CHECK THE THERMISTOR CIRCUIT FOR A SHORT TO GROUND 
    • Key in OFF position.
    • Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the General Procedures portion of SUPPLEMENTAL RESTRAINT SYSTEM article.
    • Disconnect the driver seat side air bag module C327.
    • Disconnect the 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 article.
    • Fig 26: Checking Thermistor Circuit For A Short To Ground
      GF0021430Courtesy of FORD MOTOR CO.
    • Measure the resistance between DCSM C3305b-9, circuit VHS35 (VT/OG), harness side and ground.
    • Is the resistance greater than 10,000 volts? 
    1. YES  : Go to  AB33.
    2. 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 article.

  33. AB33 CHECK THE THERMISTOR AND WIRING 
      Fig 27: Checking Thermistor & Wiring
      GF0021431Courtesy of FORD MOTOR CO.
    • 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 refer to the following 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? 
    1. YES  : INSTALL a new DCSM and CARRY OUT PMI. 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 article.

    2. NO  : Go to  AB34.
  34. AB34 CHECK THE THERMISTOR 
    • Disconnect: Backrest TED C3310
    • Fig 28: Checking Blower Speed Control
      GF0021397Courtesy of FORD MOTOR CO.
    • Measure the resistance between backrest TED pin 5 and pin 8, component side. Note the ambient temperature and refer to the following 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? 
    1. YES  : REPAIR the affected 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 article.

    2. 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 article.