Pinpoint Test AY: DTC B2730

Seats

Pinpoint Tests

Pinpoint Test AY: DTC B2730

Refer to Wiring Diagram Set 119, Climate Controlled Seats for schematic and connector information. Diagrams By Number

Normal Operation

Both the driver and front passenger climate controlled seats are independently controlled electronically 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, diagnostic testing can be carried out with the ignition switch ON and the engine OFF. The system receives voltage from Battery Junction Box (BJB) fuse 16 (30A) supplying battery voltage on circuit SBB16 (VT/RD) into DCSM C3036a pins E and F. If voltage is disconnected from either pin E or F of DCSM C3036a with the connection remaining on the other circuit, both seats will remain operational because the circuits are connected internally in the DCSM. However, if a fault occurs setting a DTC specific to either climate controlled seat, only the affected seat will be disabled by the DCSM and the other will remain operational.

Each driver and front passenger 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). Cabin air is drawn through the blower and distributed to each of the TED modules located in the seat cushion and backrest. The TEDs 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 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 B2730 (Back Over-Temp Detected (Driver)) - In the cooling mode, if the driver seat backrest TED temperature exceeds 70°C (158°F) for more than 4 seconds, the TED is disconnected or the duct is blocked, the DCSM will shut down the driver seat system and set this DTC.
- DTC B2730 (Back Over-Temp Detected (Driver)) - In the heating mode, if the driver seat backrest TED temperature exceeds 85°C (185°F) for more than 4 seconds, the TED is disconnected or the duct is blocked, the DCSM will shut down the driver seat system and set this DTC.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Restricted backrest TED filter
- Crushed or restricted backrest foam pad
- Crushed or restricted climate controlled seat manifold
- Backrest TED assembly
- DCSM



PINPOINT TEST AY: DTC B2730

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.

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AY1 CHECK THE DCSM FOR DTCs


- Enter the following diagnostic mode on the scan tool: Self Test - DCSM.
- Was DTC B2730 retrieved during the self-test?

Yes
GO to AY2.

No
GO to AY4.

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AY2 CHECK THE TED THERMISTOR CIRCUITS FOR A SHORT TO GROUND


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the General Procedures portion of Restraint Systems.
- Disconnect: Driver Seat Side Air Bag C328.
- Disconnect: Passenger Seat Side Air Bag C327.
- Disconnect: DCSM C3036b.
- Disconnect: Backrest TED C3322.
- 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. Refer to Battery.
- Measure the resistance between:
- DCSM C3036b-9, circuit VHS35 (VT/OG), harness side and ground.
- DCSM C3036b-10, circuit RHS15 (GY/BN), harness side and ground.




- Are the resistances greater than 10,000 ohms?

Yes
GO to AY3.

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

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

CONNECT driver seat side air bag module C328.

REPOWER the SRS. REFER to Restraint Systems.

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AY3 CHECK THE TED THERMISTOR


- Measure the resistance between backrest TED C3322 pin 5 and pin 8, component side. Note the ambient temperature and refer to the following table.










- Is the resistance within the limits indicated?

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

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

CONNECT driver seat side air bag module C328.

REPOWER the SRS. REFER to Restraint Systems.

No
INSTALL a new backrest TED. REFER to Seat Backrest Thermo-Electric Device Seat Backrest Thermo-Electric Device. REPEAT the self-test. CLEAR the DTCs.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

CONNECT driver seat side air bag module C328.

REPOWER the SRS. REFER to Restraint Systems.

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AY4 CONFIRM THE FAULT


- Verify with the customer that the concern is the seat shuts OFF in heat mode.
- NOTE: A crushed seat backrest foam pad or a crushed climate controlled seat manifold may be the cause of the fault. It may be necessary to sit on the seat or place something of reasonable size and weight on the seat to recreate the fault.
- Attempt to recreate the fault. Start the vehicle and set the driver seat to HIGH heat for at least 15 minutes.
- Is the customer concern with the seat shutting OFF in heat mode or was the fault recreated?

Yes
GO to AY5.

No
Fault not present. Fault may have been set due to a past failure or incorrect use of the climate controlled seat system by repeated switching between heat and cool modes. REPEAT the self-test. CLEAR the DTCs.

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AY5 CHECK OPERATION OF THE SEAT


- Ignition ON.
- With the engine running, set both front seats to HIGH cool.
- Compare the airflow from the driver seat backrest and compare it to the airflow from the passenger seat backrest.
- Is the airflow exhausting from the driver seat backrest comparable to the airflow exhausting from the passenger seat backrest?

Yes
GO to AY14.

No
GO to AY6.

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AY6 CHECK THE BACKREST BLOWER FOR AN OBSTRUCTION OR RESTRICTED FILTER


- Ignition OFF.
- Inspect the blower of the backrest TED assembly for an obstruction or for a restricted filter.
- Is the blower obstructed or the filter restricted?

Yes
REMOVE the obstruction or INSTALL a new filter. REPEAT the self-test. CLEAR the DTCs.

No
GO to AY7.

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AY7 CHECK THE BACKREST FAN OPERATION


- Ignition ON.
- With the engine running, set both front seats to HIGH cool.
- Inspect the backrest blower for operation.
- Does the backrest blower operate?

Yes
GO to AY14.

No
GO to AY8.

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AY8 CHECK THE BLOWER SPEED CONTROL CIRCUIT FOR AN OPEN


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the General Procedures portion of Restraint Systems.
- Disconnect: Driver Seat Side Air Bag C328.
- Disconnect: Passenger Seat Side Air Bag C327.
- Disconnect: DCSM C3036c.
- Disconnect: Backrest TED C3322.
- 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. Refer to Battery.
- Measure the resistance between DCSM C3036c-12, circuit VHS16 (BU/GN), harness side and backrest TED C3322-7, circuit VHS16 (BU/GN), harness side.




- Is the resistance less than 5 ohms?

Yes
GO to AY9.

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

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

CONNECT driver seat side air bag module C328.

REPOWER the SRS. REFER to Restraint Systems.

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AY9 CHECK BLOWER CIRCUIT RHS03 (GY/OG) FOR A SHORT TO VOLTAGE


- Ignition ON.
- Measure the voltage between DCSM C3036c-15, circuit RHS03 (GY/OG), harness side and ground.




- Is any voltage present?

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

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

CONNECT driver seat side air bag module C328.

REPOWER the SRS. REFER to Restraint Systems.

No
GO to AY10.

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AY10 CHECK BLOWER CIRCUIT CHS03 (GN/BN) FOR A SHORT TO GROUND


- Ignition OFF.
- Measure the resistance between DCSM C3036c-16, circuit CHS03 (GN/BN), harness side and ground.




- Is the resistance greater than 10,000 ohms?

Yes
GO to AY11.

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

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

CONNECT driver seat side air bag module C328.

REPOWER the SRS. REFER to Restraint Systems.

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AY11 CHECK BLOWER CIRCUITS RHS03 (GY/OG) AND CHS03 (GN/BN) FOR AN OPEN


- Measure the resistance between:
- DCSM C3036c-16, circuit CHS03 (GN/BN), harness side and backrest TED C3322-2, circuit CHS03 (GN/BN), harness side.
- DCSM C3036c-15, circuit RHS03 (GY/OG), harness side and backrest TED C3322-4, circuit RHS03 (GY/OG), harness side.




- Are the resistances less than 5 ohms?

Yes
GO to AY12.

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

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

CONNECT driver seat side air bag module C328.

REPOWER the SRS. REFER to Restraint Systems.

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AY12 CHECK THE BLOWER RESISTANCE


- NOTICE: 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 C3322 pin 2 and pin 4, component side.




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

Yes
GO to AY13.

No
INSTALL a new backrest TED. REFER to Seat Backrest Thermo-Electric Device Seat Backrest Thermo-Electric Device. REPEAT the self-test. CLEAR the DTCs.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

CONNECT driver seat side air bag module C328.

REPOWER the SRS. REFER to Restraint Systems.

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AY13 CHECK THE BLOWER SPEED CONTROL RESISTANCE


- NOTICE: 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 C3322 pin 7 and pin 4, component side.




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

Yes
GO to AY14.

No
INSTALL a new backrest TED. REFER to Seat Backrest Thermo-Electric Device Seat Backrest Thermo-Electric Device. REPEAT the self-test. CLEAR the DTCs.

DISCONNECT the battery ground cable.

CONNECT passenger seat side air bag module C327.

CONNECT driver seat side air bag module C328.

REPOWER the SRS. REFER to Restraint Systems.

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AY14 CHECK THE TED INSTALLATION AND FOR CRUSHED SEAT BACKREST


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the General Procedures portion of Restraint Systems.
- Remove the seat. Refer to Seat - Front Seat - Front.
- Remove the seat backrest cover. Refer to Seat Backrest Cover - Front, Without Fold Flat Seat Backrest Cover - Front, Without Fold Flat.
- Inspect the seat backrest for the following:
- Is the TED correctly installed?
- Is the seat backrest foam pad crushed or restricted?
- Is the climate controlled seat manifold crushed or restricted?
- Is the TED correctly installed and are there no signs of damage to the foam pad and manifold?

Yes
CONNECT the battery ground cable.

INSTALL a new DCSM. REFER to Dual Climate Controlled Seat Module (DCSM) Dual Climate Controlled Seat Module (DCSM). REPEAT the self-test. CLEAR the DTCs.

REPOWER the SRS. REFER to Restraint Systems.

No
CORRECTLY install the backrest TED 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.

CONNECT passenger seat side air bag module C327.

CONNECT driver seat side air bag module C328.

REPOWER the SRS. REFER to Restraint Systems.

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