Pinpoint Test AJ: DTC B19A8
Seats
Pinpoint Test AJ: DTC B19A8
Refer to Wiring Diagram Set 119 (Fusion/Milan/MKZ, Fusion Hybrid, Milan Hybrid, MKZ Hybrid), Climate Controlled Seats for schematic and connector information. Diagrams By Number
Normal Operation
The Dual Climate Controlled Seat Module (DCSM) supplies voltage and ground to the driver seat backrest Thermo-Electric Device (TED). The DCSM also sends a speed control voltage signal to the TED to control blower speed.
- DTC B19A8 (Driver Seat Back Blower Speed Short to Ground) - If the driver seat backrest blower speed circuit is shorted to ground, the DCSM will shut down the driver seat system and set this DTC.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- TED and blower assembly
- DCSM
PINPOINT TEST AJ: DTC B19A8
NOTICE: 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: If a seat equipped with a seat mounted side air bag is being serviced, the Supplemental Restraint System (SRS) must be depowered. Refer to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
NOTE: The air bag warning lamp illuminates when the Restraints Control Module (RCM) fuse is removed and the ignition switch is ON. This is normal operation and does not indicate an SRS fault.
NOTE: The SRS must be fully operational and free of faults before releasing the vehicle to the customer.
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AJ1 CHECK THE BACKREST TED BLOWER MOTOR SPEED CONTROL CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the General Procedures portion of Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Driver Seat Side Air Bag C327.
- Disconnect: Passenger Seat Side Air Bag C313.
- Disconnect: DCSM C3305C.
- Disconnect: Backrest TED C3310.
- Measure the resistance between DCSM C3305C-12, circuit VHS16 (BU/GN), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to AJ2.
No
REPAIR the circuit. REPEAT the self-test. CLEAR the DTCs.
CONNECT driver seat side air bag module C327.
CONNECT passenger seat side air bag module C313.
REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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AJ2 CHECK THE BACKREST TED BLOWER MOTOR SPEED CONTROL AND BLOWER MOTOR GROUND CIRCUITS FOR A SHORT TOGETHER
- Measure the resistance between DCSM C3305C-12, circuit VHS16 (BU/GN), harness side and C3305C-15, circuit RHS03 (GY/OG), harness side.
- Is the resistance greater than 10,000 ohms?
Yes
INSTALL a new backrest TED. REFER to Seat Backrest Thermo-Electric Device 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 Supplemental Restraint System (SRS) Depowering and Repowering.
No
REPAIR the circuits. REPEAT the self-test. CLEAR the DTCs.
CONNECT driver seat side air bag module C327.
CONNECT passenger seat side air bag module C313.
REPOWER the SRS. REFER to Supplemental Restraint System Supplemental Restraint System (SRS) Depowering and Repowering.
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