Pinpoint Test AB: DTC B111D
Seats
Pinpoint Test AB: DTC B111D
Refer to Wiring Diagram Set 119, Climate Controlled Seats for schematic and connector information. [1][2]Diagrams By Number
Normal Operation
The Dual Climate Controlled Seat Module (DCSM) is supplied voltage at all times, but the climate controlled seat system only operates with the engine running. The system can be operated with the ignition ON engine OFF by using a scan tool to bypass the climate controlled seat buttons on the touchscreen interface. When commanding a heat or cool mode operation in this manner, it only operates in 15-second intervals. Both voltage supply circuits are spliced together internal to the DCSM (Dual Climate Controlled Seat Module) , so if one circuit becomes open, both seats can still be operated. However, if a fault occurs setting a DTC specific to either climate controlled seat, only the affected seat is disabled by the DCSM (Dual Climate Controlled Seat Module).
The seat cushion is equipped with a Thermo-Electric Device (TED) assembly that includes a seat blower (fan motor, serviced as an assembly with the TED (Thermo-Electric Device)). Similarly, the seat backrest is also equipped with its own TED (Thermo-Electric Device) assembly with blower. Cabin air is drawn through the blower and distributed to each of the TED (Thermo-Electric Device) modules located in the seat cushion and backrest. The TEDs (Thermo-Electric Devices) then heat or cool the air. The air is then directed into the foam pad and manifold where it is distributed along the surface of the cushion and backrest of the seat. Once the system is activated, the DCSM (Dual Climate Controlled Seat Module) uses a set of flexible algorithms to control the heating/cooling modes and the blower speed dependant on the HVAC module seat switch settings.
- DTC B111D (Passenger Blower Driver Overtemperature)- If the DCSM (Dual Climate Controlled Seat Module) outputs to the passenger seat blower or any components within these circuit loops are shorted to ground or cause an excessive current draw, the DCSM (Dual Climate Controlled Seat Module) will overheat, shut down the passenger seat system and set this DTC.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- TED (Thermo-Electric Device) assembly
- DCSM (Dual Climate Controlled Seat Module)
PINPOINT TEST AB : DTC B111D
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 Restraints and Safety Systems &/or Air Bag Systems.
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 (Supplemental Restraint System) fault.
NOTE: The SRS (Supplemental Restraint System) must be fully operational and free of faults before releasing the vehicle to the customer.
AB1 CHECK THE BLOWER MOTOR FEED CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Depower the SRS (Supplemental Restraint System). Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the General Procedures portion of Restraints and Safety Systems &/or Air Bag Systems.
- Disconnect: Passenger Seat Side Air Bag C313.
- Disconnect: DCSM (Dual Climate Controlled Seat Module) C3305C.
- Disconnect: Cushion TED (Thermo-Electric Device) C3303.
- Disconnect: Backrest TED (Thermo-Electric Device) C3311.
- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3305C-8, circuit CHS08 (BN/YE), harness side and ground.
Is the resistance greater than 10,000 ohms?
Yes
GO to AB2.
No
REPAIR the circuit. REPEAT the self-test.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
AB2 CHECK FOR A SHORT BETWEEN THE BLOWER MOTOR FEED AND GROUND CIRCUITS
- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3305C-7, circuit RHS08 (VT/WH), harness side and C3305C-8, circuit CHS08 (BN/YE), harness side.
Is the resistance greater than 10,000 ohms?
Yes
GO to AB3.
No
REPAIR the circuits. REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
AB3 CHECK THE BACKREST CUSHION BLOWER MOTOR RESISTANCE
- 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 (Thermo-Electric Device) C3303 pin 2 and pin 4, component side.
- backrest TED (Thermo-Electric Device) C3311 pin 2 and pin 4, component side.
Are the resistances between 4,000 and 10,000 ohms?
Yes
INSTALL a new DCSM (Dual Climate Controlled Seat Module). REFER to Dual Climate Controlled Seat Module (DCSM) . REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
No
If cushion TED (Thermo-Electric Device) resistance is not between 4,000 and 10,000 ohms, INSTALL a new cushion TED (Thermo-Electric Device). REFER to Seat Cushion Thermo-Electric Device . REPEAT the self-test. CLEAR the DTCs.
If backrest TED (Thermo-Electric Device) resistance is not between 4,000 and 10,000 ohms, INSTALL a new backrest TED (Thermo-Electric Device). REFER to Seat Backrest Thermo-Electric Device . REPEAT the self-test. CLEAR the DTCs.
DISCONNECT the battery ground cable. CONNECT passenger seat side air bag module C313. REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.