Pinpoint Test An: DTC B272B

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

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

AN1 CHECK THE BACKREST BLOWER FOR AN OBSTRUCTION OR RESTRICTED FILTER
- Check the seat for any obstruction at the TED assembly and for a restricted filter.
- Is the filter clean and blower clear of any obstruction?

Yes : GO to AN2.
No : REMOVE the obstruction or CLEAN the filter.
REPEAT the self-test. CLEAR the DTCs. TEST the system for normal operation.

AN2 CHECK OPERATION OF THE SEAT AND MONITOR SEAT TEMPERATURE USING THE SCAN TOOL
- 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)
- Start the engine.
- Operate the seat in high heat or high cool and monitor the seat operation. If a circuit fault is present, the DCSM will disable the seat.
- Monitor the cushion and backrest temperature PIDs while the seat is operating. The temperatures should be similar during operation.
- Does the seat operate and temperature PIDs indicate correct operation?

Yes : The system is operating correctly at this time. The fault may have occurred from incorrectly switching between heat and cool modes. REPEAT the self-test. CLEAR the DTCs.
No : If the seat is operational, but the backrest temperature increases greater than the cushion, GO to AN3.
If the seat does not operate, GO to AN4.

AN3 CHECK THE TED FOR CORRECT INSTALLATION AND FOR A CRUSHED CLIMATE CONTROLLED SEAT MANIFOLD
- Remove the seat backrest cover. Refer to SEAT BACKREST COVER - FRONT, WITHOUT FOLD FLAT .
- Check the TED and climate controlled seat manifold for damage, restriction and for correct installation.
- Is the TED correctly installed and the climate controlled seat manifold OK?

Yes : INSTALL a new backrest TED . REFER to SEAT BACKREST THERMO-ELECTRIC DEVICE . REPEAT the self-test. CLEAR the DTCs. TEST the system for normal operation.
No : CORRECTLY install the backrest TED or INSTALL a new climate controlled seat manifold. REPEAT the self-test. CLEAR the DTCs. TEST the system for normal operation.

AN4 CHECK THE TED THERMISTOR CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Depower the SRS . Refer to GENERAL PROCEDURES .
- Disconnect: Passenger Seat Side Air Bag Module C313.
- Disconnect: DCSM C3305B.
- Disconnect: Backrest TED C3311 .
- Measure the resistance between DCSM C3305B-4, circuit VHS36 (YE/BU), harness side and ground.
  
  Fig 1: Measuring Resistance Between DCSM C3305B-4, Circuit VHS36 (YE/BU), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10,000 ohms?

Yes : GO to AN5.
No : REPAIR the circuit. REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313.

REPOWER the SRS . REFER to GENERAL PROCEDURES

AN5 CHECK THE TED THERMISTOR CIRCUITS FOR A SHORT TOGETHER
- Measure the resistance between DCSM C3305B-4, circuit VHS36 (YE/BU), harness side and DCSM C3305B-5, circuit RHS20 (GN/BU), harness side.
  
  Fig 2: Checking TED Thermistor Circuits For Short Together
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10,000 ohms?

Yes : GO to AN6.
No : REPAIR the circuit(s). REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313.

REPOWER the SRS . REFER to GENERAL PROCEDURES

AN6 CHECK THE BLOWER CIRCUITS FOR AN OPEN
- Measure the resistance between:
  - DCSM C3305C-8, circuit CHS08 (BN/YE), harness side and backrest TED C3311-2, circuit CHS08 (BN/YE), harness side.
  - DCSM C3305C-7, circuit RHS08 (VT/WH), harness side and backrest TED C3311-4, circuit RHS08 (VT/WT), harness side.
  - DCSM C3305C-4, circuit VHS21 (BU/WH), harness side and backrest TED C3311-7, circuit VHS21 (BU/WH), harness side.
  Fig 3: Checking Blower Circuits For Open
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?

Yes : INSTALL a new cushion TED . REFER to SEAT CUSHION THERMO-ELECTRIC DEVICE . REPEAT the self-test. CLEAR the DTCs. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313.

REPOWER the SRS . REFER to GENERAL PROCEDURES
No : REPAIR the circuit(s). REPEAT the self-test. CLEAR the DTCs. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313.

REPOWER the SRS . REFER to GENERAL PROCEDURES