Part 2

Seats

Pinpoint Test AT: DTC B272D

Normal Operation

The Dual Climate Controlled Seat Module (DCSM) monitors the temperature sensor. If the temperature exceeds the specified limits, the DTC will be set.

A differential fault occurs when the cushion and backrest Thermo-Electric Devices (TEDs) on an affected seat are reporting very different temperatures to the DCSM (Dual Climate Controlled Seat Module). This may result from an airflow restriction or a circuit fault of either TED (Thermo-Electric Device) area. If a TED (Thermo-Electric Device) and foam pad is clear of obstruction and is operational, the other TED (Thermo-Electric Device) and circuitry on the seat should be checked. It is important to note that a TED (Thermo-Electric Device) with a higher temperature may be operating correctly and 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 longer than 4 seconds, the TED (Thermo-Electric Device) is disconnected or the duct is blocked, this DTC will set. 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). If the system is able to recover, it will function 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) will shut down the passenger seat system. Principles of Operation

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 foam pad

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

- DCSM (Dual Climate Controlled Seat Module)

PINPOINT TEST AT : DTC B272D

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 switch is ON.

NOTE: The Supplemental Restraint System (SRS) must be fully operational and free of faults before releasing the vehicle to the customer.

AT17 CHECK THE THERMISTOR FEED CIRCUIT FOR A SHORT TO GROUND

- Ignition OFF.

- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3265B-2, circuit VHS27 (WH/OG), harness side and ground.

Is the resistance greater than 10,000 ohms?

Yes
GO to AT18.

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

DISCONNECT the battery ground cable.

CONNECT passenger seat safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3377.

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

AT18 CHECK THE THERMISTOR AND WIRING RESISTANCE

- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3265B-2, circuit VHS27 (WH/OG), harness side and DCSM (Dual Climate Controlled Seat Module) C3265B-3, circuit RHS10 (BU/OG), harness side. Note the ambient temperature and compare result 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) . CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3377.

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

No
GO to AT19.

AT19 CHECK THE THERMISTOR RESISTANCE

- Disconnect: Cushion TED (Thermo-Electric Device) C3040.

- Measure the resistance between cushion TED (Thermo-Electric Device) pin 5 and pin 8, component side. Note the ambient temperature and compare result 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 circuit(s). CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3377.

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 - Front Row . CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3377.

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

AT20 CHECK FOR CORRECT TED (Thermo-Electric Device) INSTALLATION AND FOR CRUSHED FOAM

- Ignition OFF.

- Remove the seat. Refer to Seat- Front .

- Remove the seat backrest trim cover. Refer to Seat Backrest Cover- Front .

- 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 TED (Thermo-Electric Device) correctly installed and foam pad OK?

Yes
GO to AT21.

No
Correctly INSTALL the backrest TED (Thermo-Electric Device) or INSTALL a new seat backrest foam pad. CLEAR the DTCs. REPEAT the self-test.

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

AT21 CHECK THE CUSHION TED (Thermo-Electric Device) GROUND CIRCUIT FOR A SHORT TO VOLTAGE

- Ignition OFF.

- Position the front passenger seat in the vehicle and connect the seat-to-floor connectors.

- 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 Module C3377.

- Disconnect: Passenger Seat Safety Belt Buckle Pretensioner C3066.

- Disconnect: DCSM (Dual Climate Controlled Seat Module) C3265A.

- 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 voltage between DCSM (Dual Climate Controlled Seat Module) C3265A-B, circuit RHS07 (BU), harness side and ground.

Is the resistance greater than 10,000 ohms?

Yes
GO to AT23.

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

DISCONNECT the battery ground cable.

CONNECT passenger seat safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3377.

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

AT23 CHECK THE CUSHION TED (Thermo-Electric Device) AND WIRING RESISTANCE

- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3265A-A circuit CHS07 (GY/BU), harness side and DCSM (Dual Climate Controlled Seat Module) C3265A-B, circuit RHS07 (BU), harness side.

Is the resistance between 0.9 and 10 ohms?

Yes
GO to AT25.

No
GO to AT24.

AT24 CHECK THE CUSHION TED (Thermo-Electric Device) RESISTANCE

- Disconnect: Cushion TED (Thermo-Electric Device) C3040.

- Measure the resistance between cushion TED (Thermo-Electric Device) C3040 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 safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3377.

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 - Front Row . CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3377.

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

AT25 CHECK THE BLOWER MOTOR FEED AND SPEED CONTROL CIRCUITS FOR A SHORT TO VOLTAGE

- Disconnect: DCSM (Dual Climate Controlled Seat Module) C3265C.

- Ignition ON.

- Measure voltage between:
- DCSM (Dual Climate Controlled Seat Module) C3265C-8, circuit CHS08 (BN/YE), harness side and ground.

- DCSM (Dual Climate Controlled Seat Module) C3265C-4, circuit VHS21 (BU/WH), harness side and ground.

Is voltage present on either circuit?

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

DISCONNECT the battery ground cable.

CONNECT passenger seat safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3377.

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

No
GO to AT26.

AT26 CHECK THE BLOWER MOTOR FEED AND SPEED CONTROL CIRCUITS FOR A SHORT TO GROUND

- Ignition OFF.

- Measure the resistance between:
- DCSM (Dual Climate Controlled Seat Module) C3265C-8, circuit CHS08 (BN/YE), harness side and ground.

- DCSM (Dual Climate Controlled Seat Module) C3265C-4, circuit VHS21 (BU/WH), harness side and ground.

Are the resistances greater than 10,000 ohms?

Yes
GO to AT27.

No
REPAIR the circuit(s). CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3377.

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

AT27 CHECK THE BLOWER MOTOR AND WIRING RESISTANCE

- NOTE: The ohmmeter must be connected with the positive lead to DCSM (Dual Climate Controlled Seat Module) C3265C-8, circuit CHS08 (BN/YE) and the negative lead to DCSM (Dual Climate Controlled Seat Module) C3265C-7, circuit RHS08 (VT/WH) 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 DCSM (Dual Climate Controlled Seat Module) C3265C-8, circuit CHS08 (BN/YE), harness side and DCSM (Dual Climate Controlled Seat Module) C3265C-7, circuit RHS08 (VT/WH), harness side.

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

Yes
GO to AT29.

No
GO to AT28.

AT28 CHECK THE BLOWER MOTOR RESISTANCE

- Disconnect: Backrest TED (Thermo-Electric Device) C3039.

- 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 backrest TED (Thermo-Electric Device) C3039 pin 2 and pin 4, component side.

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

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

DISCONNECT the battery ground cable.

CONNECT passenger seat safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3377.

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 - Front Row . CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3377.

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

AT29 CHECK THE BLOWER MOTOR GROUND CIRCUIT TO BLOWER MOTOR SPEED CONTROL CIRCUIT RESISTANCE

- NOTE: The ohmmeter must be connected with the positive lead to C3265C-4, circuit VHS21 (BU/WH), harness side and the negative lead to C3265C-7, circuit RHS08 (VT/WH), harness side 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 DCSM (Dual Climate Controlled Seat Module) C3265C-4, circuit VHS21 (BU/WH), harness side and DCSM (Dual Climate Controlled Seat Module) C3265C-7, circuit RHS08 (VT/WH), harness side.

Is the resistance between 240K and 4M ohms?

Yes
GO to AT31.

No
GO to AT30.

AT30 CHECK THE BLOWER MOTOR SPEED CONTROL RESISTANCE

- Disconnect: Backrest TED (Thermo-Electric Device) C3039.

- NOTE: The ohmmeter must be connected with the positive lead to pin 7 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 backrest TED (Thermo-Electric Device) C3039 pin 7 and pin 4, component side.

Is the resistance between 240K and 4M ohms?

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

DISCONNECT the battery ground cable.

CONNECT passenger seat safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3377.

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 - Front Row . CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3377.

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

AT31 CHECK THE THERMISTOR FEED CIRCUIT FOR A SHORT TO VOLTAGE

- Disconnect: DCSM (Dual Climate Controlled Seat Module) C3265B.

- Ignition ON.

- Measure voltage between DCSM (Dual Climate Controlled Seat Module) C3265B-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 safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3377.

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

No
GO to AT32.

AT32 CHECK THE THERMISTOR 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 Module C3377.

- Disconnect: Passenger Seat Safety Belt Buckle Pretensioner C3066.

- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3265B-4, circuit VHS36 (YE/BU), harness side and ground.

Is the resistance greater than 10,000 ohms?

Yes
GO to AT33.

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

DISCONNECT the battery ground cable.

CONNECT passenger seat safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3377.

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

AT33 CHECK THE THERMISTOR AND WIRING RESISTANCE AT THE DCSM (Dual Climate Controlled Seat Module)

- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3265B-4, circuit VHS36 (YE/BU), harness side and DCSM (Dual Climate Controlled Seat Module) C3265B-5, circuit RHS20 (GN/BU), harness side. Note the ambient temperature and compare result 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) . CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger seat safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3377.

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

No
GO to AT34.

AT34 CHECK THE TED (Thermo-Electric Device) THERMISTOR RESISTANCE

- Disconnect: Backrest TED (Thermo-Electric Device) C3039.

- Measure the resistance between backrest TED (Thermo-Electric Device) pin 5 and pin 8, component side. Note the ambient temperature and compare result 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