Pinpoint Test AA: DTC B111D
Seats
Pinpoint Test AA: DTC B111D
Normal Operation
Climate controlled seats are independently controlled by the Dual Climate Controlled Seat Module (DCSM) mounted to the bottom of the passenger seat cushion. The climate controlled seat system only operates with the engine running, however, if using a scan tool to command the DCSM (Dual Climate Controlled Seat Module), diagnostic testing can be carried out with the ignition ON. The system receives voltage from Battery Junction Box (BJB) fuse 22 (30A) supplying voltage into DCSM (Dual Climate Controlled Seat Module) C3265a pins E and F, circuit CBX01 (GN/RD). If voltage is disconnected from either pin E or F of DCSM (Dual Climate Controlled Seat Module) C3265a both seats will remain operational because the voltage supply circuits are connected internally in the DCSM (Dual Climate Controlled Seat Module). However, if a fault occurs setting a DTC specific to either climate controlled seat, only the affected seat will be disabled by the DCSM (Dual Climate Controlled Seat Module).
The seat cushion and backrest are 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)). Cabin air is drawn through the blower and distributed to each of the TED (Thermo-Electric Device) modules. 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 AA : 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: 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.
AA1 CHECK CIRCUIT CHS08 (BN/YE) 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 C3133.
- Disconnect: Passenger Safety Belt Buckle Pretensioner C3066.
- Disconnect: DCSM (Dual Climate Controlled Seat Module) C3265c.
- Disconnect: Cushion TED (Thermo-Electric Device) C3040.
- Disconnect: Backrest TED (Thermo-Electric Device) C3039.
- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3265C-8, circuit CHS08 (BN/YE), harness side and ground.
Is the resistance greater than 10,000 ohms?
Yes
GO to AA2.
No
REPAIR the circuit. REPEAT the self-test.
DISCONNECT the battery ground cable.
CONNECT passenger safety belt buckle pretensioner C3066.
CONNECT passenger seat side air bag module C3133.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
AA2 CHECK FOR A SHORT BETWEEN CIRCUITS RHS08 (VT/WH) AND CHS08 (BN/YE)
- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3265C-7, circuit RHS08 (VT/WH), harness side and C3265C-8, circuit CHS08 (BN/YE), harness side.
Is the resistance greater than 10,000 ohms?
Yes
GO to AA3.
No
REPAIR the circuits. CLEAR the DTCs. REPEAT the self-test.
DISCONNECT the battery ground cable.
CONNECT passenger safety belt buckle pretensioner C3066.
CONNECT passenger seat side air bag module C3133.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
AA3 CHECK THE BACKREST BLOWER AND CUSHION BLOWER RESISTANCES
- 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) C3040 pin 2 and pin 4, component side.
- backrest TED (Thermo-Electric Device) C3039 pin 2 and pin 4, component side.
Are the resistances between 4,000 ohms and 10,000 ohms?
Yes
INSTALL a new DCSM (Dual Climate Controlled Seat Module). REFER to Dual Climate Controlled Seat Module (DCSM) . CLEAR the DTCs. REPEAT the self-test.
DISCONNECT the battery ground cable.
CONNECT passenger safety belt buckle pretensioner C3066.
CONNECT passenger seat side air bag module C3133.
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 . CLEAR the DTCs. REPEAT the self-test.
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 . CLEAR the DTCs. REPEAT the self-test.
DISCONNECT the battery ground cable.
CONNECT passenger safety belt buckle pretensioner C3066.
CONNECT passenger seat side air bag module C3133.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.