Part 2

Seats

Pinpoint Test AR: DTC B272D

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, the climate controlled seat system 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 commanded climate controlled seat settings.

A differential fault occurs when the cushion and backrest TEDs (Thermo-Electric Devices) on an affected seat are reporting very different temperatures to the DCSM (Dual Climate Controlled Seat Module). This may result from an air flow restriction or a circuit fault of either TED (Thermo-Electric Device) area. If a TED (Thermo-Electric Device) and manifold is clear of obstruction and is operational, check the other TED (Thermo-Electric Device) and circuitry on the seat. It is important to note that a TED (Thermo-Electric Device) with a higher temperature may be operating correctly and is not the area of concern. The other TED (Thermo-Electric Device) may be indicating a much lower temperature, causing the DTC to set.

- DTC B272D (Passenger Differential Temperature Fault)- If there is a temperature differential between the passenger backrest and cushion TED (Thermo-Electric Device) of 60°C (108°F) or more for more than 4 seconds, the TED (Thermo-Electric Device) is disconnected or the duct is blocked, this DTC sets. When this happens the first time in a key cycle, the DCSM (Dual Climate Controlled Seat Module) puts the passenger seat system into recovery mode (see Principles of Operation Principles Of Operation). If the system is able to recover, it functions normally. If the system is able to recover and it occurs a second time in the same key cycle, the DCSM (Dual Climate Controlled Seat Module) shuts down the passenger seat system.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- Restricted cushion or backrest TED (Thermo-Electric Device) filter

- Crushed or restricted cushion or backrest foam pad

- Crushed or restricted cushion or backrest climate controlled seat manifold

- Cushion or backrest TED (Thermo-Electric Device) assembly

- DCSM (Dual Climate Controlled Seat Module)

AR16 CHECK THERMISTOR CIRCUIT 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 C327.

- Disconnect: DCSM (Dual Climate Controlled Seat Module) C3036B.

- 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) C3036B-2, circuit VHS27 (WH/OG), harness side and ground.






Is any voltage present?

Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

No
GO to AR17.

AR17 CHECK THERMISTOR CIRCUIT FOR A SHORT TO GROUND

- Ignition OFF.

- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3036B-2, circuit VHS27 (WH/OG), harness side and ground.






Is the resistance greater than 10,000 ohms?

Yes
GO to AR18.

No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

AR18 CHECK THE TED (Thermo-Electric Device) THERMISTOR AND WIRING RESISTANCE

- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3036B-2, circuit VHS27 (WH/OG), harness side and DCSM (Dual Climate Controlled Seat Module) C3036B-3, circuit RHS10 (BU/OG), harness side. Note the ambient temperature and refer to the following table.

Temperature Resistance 0-10°C (32-50°F) 2,782-1,663 ohms 10-20°C (50-68°F) 1,837-1,140 ohms 20-30°C (68-86°F) 1,260-806 ohms 30-40°C (86-104°F) 893-570 ohms 40-50°C (104-122°F) 630-428 ohms






Is the resistance within the limits indicated?

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 C327.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

No
GO to AR19.

AR19 CHECK THE THERMISTOR

- Disconnect: Passenger Cushion TED (Thermo-Electric Device) C3328.

- Measure the resistance between passenger cushion TED (Thermo-Electric Device) pin 5 and pin 8, component side. Note the ambient temperature and refer to the following table.

Temperature Resistance 0-10°C (32-50°F) 2,782-1,663 ohms 10-20°C (50-68°F) 1,837-1,140 ohms 20-30°C (68-86°F) 1,260-806 ohms 30-40°C (86-104°F) 893-570 ohms 40-50°C (104-122°F) 630-428 ohms






Is the resistance within the limits indicated?

Yes
REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

No
INSTALL a new cushion TED (Thermo-Electric Device). REFER to Seat Cushion Thermo-Electric Device . CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

AR20 CHECK THE TED (Thermo-Electric Device) INSTALLATION AND FOR A CRUSHED SEAT BACKREST

- 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.

- Remove the seat. Refer to Seat- Front .

- Remove the seat backrest cover. Refer to Seat Backrest Cover- Front, Without Fold Flat .

- Inspect the seat backrest for the following:
- Is the backrest blower obstructed?

- Is the blower filter restricted or plugged?

- Is the TED (Thermo-Electric Device) correctly installed?

- Is the seat backrest foam pad crushed or restricted?

- Is the climate controlled seat manifold crushed or restricted?


Is the TED (Thermo-Electric Device) correctly installed and are there no signs of damage to the foam pad and manifold?

Yes
GO to AR21.

No
Correctly INSTALL the backrest TED (Thermo-Electric Device) or INSTALL a new seat backrest foam pad and/or climate controlled seat manifold. CONNECT the battery ground cable. REPEAT the self-test. CLEAR the DTCs.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

AR21 CHECK CUSHION TED (Thermo-Electric Device) CIRCUIT RHS07 (BU) FOR SHORT TO VOLTAGE

- Ignition OFF.

- Disconnect: DCSM (Dual Climate Controlled Seat Module) C3036A.

- NOTE: Do not connect the seat side air bag electrical connector at this time.
Position the front passenger seat in the vehicle and connect the seat-to-floor connectors.


- 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) C3036A-B, circuit RHS07 (BU), harness side and ground.






Is any voltage present?

Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

No
GO to AR22.

AR22 CHECK THE PASSENGER CUSHION TED (Thermo-Electric Device) CIRCUIT FOR A SHORT TO GROUND

- Ignition OFF.

- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3036A-A, circuit CHS07 (GY/BU), harness side and ground.






Is the resistance greater than 10,000 ohms?

Yes
GO to AR23.

No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

AR23 CHECK THE PASSENGER CUSHION TED (Thermo-Electric Device) AND WIRING RESISTANCE

- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3036A-A circuit CHS07 (GY/BU), harness side and DCSM (Dual Climate Controlled Seat Module) C3036A-B, circuit RHS07 (BU), harness side.






Is the resistance between 0.9 and 10 ohms?

Yes
GO to AR25.

No
GO to AR24.

AR24 CHECK THE PASSENGER CUSHION TED (Thermo-Electric Device) RESISTANCE

- Disconnect: Passenger Cushion TED (Thermo-Electric Device) C3328.

- Measure the resistance between passenger cushion TED (Thermo-Electric Device) C3328 pin 1 and pin 3, component side.






Is the resistance between 0.9 and 10 ohms?

Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

No
INSTALL a new cushion TED (Thermo-Electric Device). REFER to Seat Cushion Thermo-Electric Device . CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

AR25 CHECK THE BLOWER AND SPEED CONTROL CIRCUITS FOR A SHORT TO VOLTAGE

- Disconnect: DCSM (Dual Climate Controlled Seat Module) C3036C.

- Ignition ON.

- Measure the voltage between:
- DCSM (Dual Climate Controlled Seat Module) C3036C-8, circuit CHS08 (BN/YE), harness side and ground.

- DCSM (Dual Climate Controlled Seat Module) C3036C-4, circuit VHS21 (BU/WH), harness side and ground.







Is voltage present on either circuit?

Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

No
GO to AR26.

AR26 CHECK THE BLOWER AND SPEED CONTROL CIRCUITS FOR A SHORT TO GROUND

- Ignition OFF.

- Measure the resistance between:
- DCSM (Dual Climate Controlled Seat Module) C3036C-8, circuit CHS08 (BN/YE), harness side and ground.

- DCSM (Dual Climate Controlled Seat Module) C3036C-4, circuit VHS21 (BU/WH), harness side and ground.







Are the resistances greater than 10,000 ohms?

Yes
GO to AR27.

No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

AR27 CHECK THE BLOWER AND WIRING RESISTANCE

- NOTICE: Connect the ohmmeter with the positive lead to Dual Climate Controlled Seat Module (DCSM) C3036C-8, circuit CHS08 (BN/YE) and the negative lead to DCSM (Dual Climate Controlled Seat Module) C3036C-7, circuit RHS08 (VT/WH) when measuring. Ohmmeter leads incorrectly connected can result in false readings and lead to incorrect identification of components that are not faulty.

Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3036C-8, circuit CHS08 (BN/YE), harness side and DCSM (Dual Climate Controlled Seat Module) C3036C-7, circuit RHS08 (VT/WH), harness side.






Is the resistance between 4,000 ohms and 10,000 ohms?

Yes
GO to AR29.

No
GO to AR28.

AR28 CHECK THE BLOWER RESISTANCE

- Disconnect: Passenger Backrest TED (Thermo-Electric Device) C3326.

- NOTICE: Connect the ohmmeter with the positive lead to pin 2 and the negative lead to pin 4 when measuring. Ohmmeter leads incorrectly connected can result in false readings and lead to incorrect identification of components that are not faulty.

Measure the resistance between passenger backrest TED (Thermo-Electric Device) C3326 pin 2 and pin 4, component side.







Is the resistance between 4,000 ohms and 10,000 ohms?

Yes
REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

No
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 seat side air bag module C327.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

AR29 CHECK THE BLOWER SPEED CONTROL AND CIRCUIT RESISTANCE

- NOTICE: Connect the ohmmeter with the positive lead to C3036C-4, circuit VHS21 (BU/WH), harness side and the negative lead to C3036C-7, circuit RHS08 (VT/WH), harness side when measuring. Ohmmeter leads incorrectly connected can result in false readings and lead to incorrect identification of components that are not faulty.

Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3036C-4, circuit VHS21 (BU/WH), harness side and DCSM (Dual Climate Controlled Seat Module) C3036C-7, circuit RHS08 (VT/WH), harness side.






Is the resistance between 240,000 ohms and 420,000 ohms?

Yes
GO to AR31.

No
GO to AR30.

AR30 CHECK THE BLOWER SPEED CONTROL RESISTANCE

- Disconnect: Passenger Backrest TED (Thermo-Electric Device) C3326.

- NOTICE: Connect the ohmmeter with the positive lead to pin 7 and the negative lead to pin 4 when measuring. Ohmmeter leads incorrectly connected can result in false readings and lead to incorrect identification of components that are not faulty.

Measure the resistance between passenger backrest TED (Thermo-Electric Device) C3326 pin 7 and pin 4, component side.







Is the resistance between 240,000 ohms and 420,000 ohms?

Yes
REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

No
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 seat side air bag module C327.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

AR31 CHECK THERMISTOR CIRCUIT 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 C327.

- Disconnect: DCSM (Dual Climate Controlled Seat Module) C3036B.

- 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) C3036B-4, circuit VHS36 (YE/BU), harness side and ground.






Is any voltage present?

Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

No
GO to AR32.

AR32 CHECK THERMISTOR CIRCUIT FOR A SHORT TO GROUND

- Ignition OFF.

- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3036B-4, circuit VHS36 (YE/BU), harness side and ground.






Is the resistance greater than 10,000 ohms?

Yes
GO to AR33.

No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

AR33 CHECK THE PASSENGER TED (Thermo-Electric Device) THERMISTOR AND WIRING RESISTANCE AT THE DCSM (Dual Climate Controlled Seat Module)

- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3036B-4, circuit VHS36 (YE/BU), harness side and DCSM (Dual Climate Controlled Seat Module) C3036B-5, circuit RHS20 (GN/BU), harness side. Note the ambient temperature and refer to the following table.

Temperature Resistance 0-10°C (32-50°F) 2,782-1,663 ohms 10-20°C (50-68°F) 1,837-1,140 ohms 20-30°C (68-86°F) 1,260-806 ohms 30-40°C (86-104°F) 893-570 ohms 40-50°C (104-122°F) 630-428 ohms






Is the resistance within the limits indicated?

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 C327.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

No
GO to AR34.

AR34 CHECK THE PASSENGER TED (Thermo-Electric Device) THERMISTOR RESISTANCE

- Disconnect: Passenger Backrest TED (Thermo-Electric Device) C3326.

- Measure the resistance between passenger backrest TED (Thermo-Electric Device) pin 5 and pin 8, component side. Note the ambient temperature and refer to the following table.

Temperature Resistance 0-10°C (32-50°F) 2,782-1,663 ohms 10-20°C (50-68°F) 1,837-1,140 ohms 20-30°C (68-86°F) 1,260-806 ohms 30-40°C (86-104°F) 893-570 ohms 40-50°C (104-122°F) 630-428 ohms






Is the resistance within the limits indicated?

Yes
REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.

No
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 seat side air bag module C327.

REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.