Pinpoint Test AR: DTC B272F
Seats
Pinpoint Test AR: DTC B272F
Refer to Wiring Diagram Set 119, Climate Controlled Seats for schematic and connector information. [1][2]Diagrams By Number
Normal Operation
The passenger climate controlled seat blowers are located within the backrest and cushion Thermo-Electric Devices (TEDs). The Dual Climate Controlled Seat Module (DCSM) supplies voltage to both blowers on circuit CHS08 (BN/YE) and ground to both blowers on circuit RHS08 (VT/WH). The blowers are independently controlled by separate speed control circuits from the DCSM (Dual Climate Controlled Seat Module).
- DTC B272F (Passenger Ignition Run/Blower Circuit Short to Ground [this DTC sets for an open or short to voltage])- If either the blower voltage supply or return circuits are open (to both cushion and backrest blowers) or shorted to voltage, the DTC is set and after 4-6 seconds the DCSM (Dual Climate Controlled Seat Module) disables outputs to the passenger seat. The DTC will also set if the blower voltage supply or return circuit is open to only one blower when DCSM (Dual Climate Controlled Seat Module) supply voltage is less than 12 volts.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- HVAC module
- Backrest or cushion TED (Thermo-Electric Device)
- DCSM (Dual Climate Controlled Seat Module)
PINPOINT TEST AR : DTC B272F
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.
AR1 CHECK THE TED (Thermo-Electric Device) BLOWER MOTOR CIRCUITS FOR A SHORT TO VOLTAGE
- 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.
- WARNING: Make sure no one is in the vehicle and there is nothing blocking or placed in front of any air bag module when the battery is connected. Failure to follow these instructions may result in serious personal injury in the event of an accidental deployment.
Connect the battery ground cable.
- Ignition ON.
- Measure the voltage between DCSM (Dual Climate Controlled Seat Module) C3305C, harness side and ground using the following chart.
DCSM (Dual Climate Controlled Seat Module) Connector Circuit C3305C-8 CHS08 (BN/YE) C3305C-7 RHS08 (VT/WH)
Is voltage present on either circuit?
Yes
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 (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
No
GO to AR2.
AR2 CHECK THE TED (Thermo-Electric Device) BLOWER MOTOR CIRCUITS FOR AN OPEN
- Ignition OFF.
- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3305C, harness side and cushion TED (Thermo-Electric Device) C3300, harness side using the following chart.
DCSM (Dual Climate Controlled Seat Module) Connector Circuit Cushion TED (Thermo-Electric Device) Connector C3305C-8 CHS08 (BN/YE) C3303-2 C3305C-7 RHS08 (VT/WH) C3303-4
Are the resistances less than 5 ohms?
Yes
GO to AR3.
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 (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
AR3 CHECK THE RESISTANCE OF THE CUSHION AND BACKREST TED (Thermo-Electric Device) BLOWER MOTORS
- 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 pins 2 and 4, component side.
- backrest TED (Thermo-Electric Device) C3311 pins 2 and 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 the 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 the 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.