Part 2

Seats

Pinpoint Test AS: DTC B272C

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 manifold 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 B272C (Driver Differential Temperature Fault)- If there is a temperature differential between the driver 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 driver 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 driver 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 cushion or backrest foam pad

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

- DCSM (Dual Climate Controlled Seat Module)

PINPOINT TEST AS : DTC B272C

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.

AS17 CHECK THE THERMISTOR FEED CIRCUIT FOR A SHORT TO GROUND

- Ignition OFF.

- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3265B-7, circuit VHS26 (VT), harness side and ground.

Is the resistance greater than 10,000 ohms?

Yes
GO to AS18.

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.

CONNECT driver seat safety belt buckle pretensioner C3065.

CONNECT driver seat side air bag module C3378.

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

AS18 CHECK THE 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) C3265B-7, circuit VHS26 (VT), harness side and DCSM (Dual Climate Controlled Seat Module) C3265B-8, circuit RHS05 (YE/VT), 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.

CONNECT driver seat safety belt buckle pretensioner C3065.

CONNECT driver seat side air bag module C3378.

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

No
GO to AS19.

AS19 CHECK THE TED (Thermo-Electric Device) THERMISTOR RESISTANCE

- Disconnect: Cushion TED (Thermo-Electric Device) C3035.

- 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.

CONNECT driver seat safety belt buckle pretensioner C3065.

CONNECT driver seat side air bag module C3378.

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.

CONNECT driver seat safety belt buckle pretensioner C3065.

CONNECT driver seat side air bag module C3378.

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

AS20 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 AS21.

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.

AS21 CHECK THE CUSHION TED (Thermo-Electric Device) GROUND CIRCUIT FOR A SHORT TO VOLTAGE

- Ignition OFF.

- Position the driver 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: Driver Seat Side Air Bag Module C3378.

- Disconnect: Driver Seat Safety Belt Buckle Pretensioner C3065.

- 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-H, circuit RHS02 (BU/OG), harness side and ground.

Is the resistance greater than 10,000 ohms?

Yes
GO to AS23.

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.

CONNECT driver seat safety belt buckle pretensioner C3065.

CONNECT driver seat side air bag module C3378.

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

AS23 CHECK THE RESISTANCE OF THE CUSHION TED (Thermo-Electric Device) AND WIRING

- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3265A-G circuit CHS02 (YE/BU), harness side and DCSM (Dual Climate Controlled Seat Module) C3265A-H, circuit RHS02 (BU/OG), harness side.

Is the resistance between 0.9 and 10 ohms?

Yes
GO to AS25.

No
GO to AS24.

AS24 CHECK THE CUSHION TED (Thermo-Electric Device) RESISTANCE

- Disconnect: Cushion TED (Thermo-Electric Device) C3035.

- Measure the resistance between cushion TED (Thermo-Electric Device) C3035 pin 1 and pin 3, component side.

Is the resistance between 0.9 and 10 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.

CONNECT driver seat safety belt buckle pretensioner C3065.

CONNECT driver seat side air bag module C3378.

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.

CONNECT driver seat safety belt buckle pretensioner C3065.

CONNECT driver seat side air bag module C3378.

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

AS25 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-16, circuit CHS03 (GN/BN), harness side and ground.

- DCSM (Dual Climate Controlled Seat Module) C3265C-12, circuit VHS16 (BU/GN), 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.

CONNECT driver seat safety belt buckle pretensioner C3065.

CONNECT driver seat side air bag module C3378.

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

No
GO to AS26.

AS26 CHECK THE BLOWER MOTOR AND SPEED CONTROL FEED CIRCUITS FOR A SHORT TO GROUND

- Ignition OFF.

- Measure the resistance between:
- DCSM (Dual Climate Controlled Seat Module) C3265C-16, circuit CHS03 (GN/BN), harness side and ground.

- DCSM (Dual Climate Controlled Seat Module) C3265C-12, circuit VHS16 (BU/GN), harness side and ground.

Are the resistances greater than 10,000 ohms?

Yes
GO to AS27.

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.

CONNECT driver seat safety belt buckle pretensioner C3065.

CONNECT driver seat side air bag module C3378.

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

AS27 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-16, circuit CHS03 (GN/BN) and the negative lead to DCSM (Dual Climate Controlled Seat Module) C3265C-15, circuit RHS03 (GY/OG) 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-16, circuit CHS03 (GN/BN), harness side and DCSM (Dual Climate Controlled Seat Module) C3265C-15, circuit RHS03 (GY/OG), harness side.

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

Yes
GO to AS29.

No
GO to AS28.

AS28 CHECK THE BLOWER MOTOR RESISTANCE

- Disconnect: Backrest TED (Thermo-Electric Device) C3034.

- 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) C3034 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.

CONNECT driver seat safety belt buckle pretensioner C3065.

CONNECT driver seat side air bag module C3378.

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.

CONNECT driver seat safety belt buckle pretensioner C3065.

CONNECT driver seat side air bag module C3378.

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

AS29 CHECK THE BLOWER MOTOR SPEED CONTROL AND CIRCUIT RESISTANCE

- NOTE: The ohmmeter must be connected with the positive lead to C3265C-12, circuit VHS16 (BU/GN), harness side and the negative lead to C3265C-15, circuit RHS03 (GY/OG), 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-12, circuit VHS16 (BU/GN) harness side and DCSM (Dual Climate Controlled Seat Module) C3265C-15, circuit RHS03 (GY/OG), harness side.

Is the resistance between 240K and 4M ohms?

Yes
GO to AS31.

No
GO to AS30.

AS30 CHECK THE BLOWER MOTOR SPEED CONTROL RESISTANCE

- Disconnect: Backrest TED (Thermo-Electric Device) C3034.

- 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) C3034 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.

CONNECT driver seat safety belt buckle pretensioner C3065.

CONNECT driver seat side air bag module C3378.

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.

CONNECT driver seat safety belt buckle pretensioner C3065.

CONNECT driver seat side air bag module C3378.

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

AS31 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-9, circuit VHS35 (VT/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 safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3377.

CONNECT driver seat safety belt buckle pretensioner C3065.

CONNECT driver seat side air bag module C3378.

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

No
GO to AS32.

AS32 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: Driver Seat Side Air Bag Module C3378.

- Disconnect: Driver Seat Safety Belt Buckle Pretensioner C3065.

- Disconnect: Passenger Seat Side Air Bag Module C3377.

- Disconnect: Passenger Seat Safety Belt Buckle Pretensioner C3066.

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

- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3265B-9, circuit VHS35 (VT/OG), harness side and ground.

Is the resistance greater than 10,000 ohms?

Yes
GO to AS33.

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.

CONNECT driver seat safety belt buckle pretensioner C3065.

CONNECT driver seat side air bag module C3378.

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

AS33 CHECK THE TED (Thermo-Electric Device) THERMISTOR AND WIRING RESISTANCE

- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3265B-9, circuit VHS35 (VT/OG), harness side and DCSM (Dual Climate Controlled Seat Module) C3265B-10, circuit RHS15 (GY/BN), 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.

CONNECT driver seat safety belt buckle pretensioner C3065.

CONNECT driver seat side air bag module C3378.

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

No
GO to AS34.

AS34 CHECK THE TED (Thermo-Electric Device) THERMISTOR RESISTANCE

- Disconnect: Backrest TED (Thermo-Electric Device) C3034.

- 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