Pinpoint Test Al: DTC B2729

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.

AL1 CHECK THE CUSHION 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 AL2.
No : REMOVE the obstruction or INSTALL a new filter. REPEAT the self-test. CLEAR the DTCs. TEST the system for normal operation.

AL2 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.
  - Seat cushion thermal electric device temperature (CSHTEMP)
  - Seat back thermal electric device temperature (BK_TEMP)
- 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 cushion temperature increases greater than the backrest, GO to AL3.
If the seat does not operate, GO to AL4.

AL3 CHECK THE TED FOR CORRECT INSTALLATION AND FOR A CRUSHED CLIMATE CONTROLLED SEAT MANIFOLD
- Remove the seat cushion cover. Refer to SEAT CUSHION COVER - FRONT .
- 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 cushion TED . REFER to SEAT CUSHION THERMO-ELECTRIC DEVICE .
REPEAT the self-test. CLEAR the DTCs. TEST the system for normal operation.
No : CORRECTLY install the cushion TED or INSTALL a new climate controlled seat manifold. REPEAT the self-test. CLEAR the DTCs. TEST the system for normal operation.

AL4 CHECK THE TED THERMISTOR 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 C327.
- Disconnect: Passenger Seat Side Air Bag C313.
- Disconnect: DCSM C3305B.
- Disconnect: Cushion TED C3300.
- Measure the resistance between DCSM C3305B-7, circuit VHS26 (VT), harness side and ground.
  
  Fig 1: 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 AL5.
No : REPAIR the circuit. REPEAT the self-test. CLEAR the DTCs. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327 and passenger seat side air bag module C313.

REPOWER the SRS . REFER to GENERAL PROCEDURES

AL5 CHECK THE TED THERMISTOR CIRCUITS FOR A SHORT TOGETHER
- Measure the resistance between DCSM C3305B-7, circuit VHS26 (VT), harness side and DCSM C3305B-8, circuit RHS05 (YE/VT), 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 AL6.
No : REPAIR the circuit(s). REPEAT the self-test. CLEAR the DTCs. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327 and passenger seat side air bag module C313.

REPOWER the SRS . REFER to GENERAL PROCEDURES

AL6 CHECK THE BLOWER CIRCUITS FOR AN OPEN
- Measure the resistance between:
  - DCSM C3305C-16, circuit CHS03 (GN/BN), harness side and cushion TED C3300-2, circuit CHS03 (GN/BN), harness side.
  - DCSM C3305C-15, circuit RHS03 (GY/OG), harness side and cushion TED C3300-4, circuit RHS03 (GY/OG), harness side.
  - DCSM C3305C-11, circuit VHS18 (BN/GN), harness side and cushion TED C3300-7, circuit VHS18 (BN/GN), 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.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327 and passenger seat side air bag module C313.

REPOWER the SRS . REFER to GENERAL PROCEDURES
No : REPAIR the circuit(s). TEST the system for normal operation. REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C327 and passenger seat side air bag module C313.

REPOWER the SRS . REFER to GENERAL PROCEDURES