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Pinpoint Test AN: DTC B272E




Seats

Pinpoint Tests

Pinpoint Test AN: DTC B272E

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

Normal Operation

The driver 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 CHS03 (GN/BN) and return ground to both blowers on circuit RHS03 (GY/OG). The backrest and cushion blowers are independently controlled by separate speed control circuits from the DCSM.

- DTC B272E (Driver 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 disables outputs to the driver seat. The DTC will also set if the blower voltage supply or return circuit is open to only one blower when DCSM 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
- DCSM



PINPOINT TEST AN: DTC B272E

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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AN1 CHECK DCSM CLIMATE-CONTROLLED SEAT HEAT COMMAND (TED_HEAT_D) PID


- Access the cushion and backrest TEDs and remove the filters to watch the TED fans.
- Enter the following diagnostic mode on the scan tool: DataLogger - DCSM - PID: TED_HEAT_D.
- NOTE: The DCSM active command TED_HEAT_D is limited to 15 seconds in the ON state.
- Operate the climate controlled seat using the active command while monitoring the cushion and backrest TEDs for fan movement.
- Did both fans turn on?

Yes
CARRY OUT the network test. If DTCs are retrieved from the HVAC module, REFER to the DTC Chart in the Diagnosis and Testing portion of Body Control Systems. Diagnostic Trouble Code (DTC) Chart If no DTCs are retrieved,
CARRY OUT the HVAC Module Cold Boot Process in the Diagnosis and Testing portion of Heating and Air Conditioning.

No
GO to AN2.

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AN2 CHECK FOR AN INTERMITTENT CONNECTION AT THE DCSM


- Ignition OFF.
- Disconnect: DCSM C3265c.
- Connect: DCSM C3265c.
- With the engine running, turn the driver climate controlled seat system on while monitoring the cushion and backrest fans for movement.
- If there is fan movement, run the driver climate controlled seat system for 2 minutes.
- Did the climate controlled seat operate correctly?

Yes
The fault is intermittent. CHECK for causes of the intermittent fault at C3265c and REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

No
GO to AN3.

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AN3 CHECK FOR AN INTERMITTENT CONNECTION AT THE CUSHION TED


- Ignition OFF.
- Disconnect: Cushion TED C3035.
- Connect: Cushion TED C3035.
- With the engine running, turn the driver climate controlled seat system on while monitoring the cushion and backrest fans for movement.
- If there is fan movement, run the driver climate controlled seat system for 2 minutes.
- Did the climate controlled seat operate correctly?

Yes
The fault is intermittent. CHECK for causes of the intermittent fault at C3035 and REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

No
GO to AN4.

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AN4 CHECK FOR AN INTERMITTENT CONNECTION AT THE BACKREST TED


- Ignition OFF.
- Disconnect: Backrest TED C3034.
- Connect: Backrest TED C3034.
- With the engine running, turn the driver climate controlled seat system on while monitoring the cushion and backrest fans for movement.
- If there is fan movement, run the driver climate controlled seat system for 2 minutes.
- Did the climate controlled seat operate correctly?

Yes
The fault is intermittent. CHECK for causes of the intermittent fault at C3034 and REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

No
GO to AN5.

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AN5 CHECK BLOWER CIRCUIT FOR A SHORT TO VOLTAGE


- 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 C3134.
- Disconnect: Driver Safety Belt Buckle Pretensioner C3065.
- Disconnect: Passenger Seat Side Air Bag C3133.
- Disconnect: Passenger Safety Belt Buckle Pretensioner C3066.
- Disconnect: DCSM C3265c.
- Disconnect: Cushion TED C3035.
- Disconnect: Backrest TED C3034.
- 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.
- Ignition ON.
- Measure the voltage between DCSM C3265c-16, circuit CHS03 (GN/BN), 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 safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3133.

CONNECT driver safety belt buckle pretensioner C3065.

CONNECT driver seat side air bag module C3134.

REPOWER the SRS. REFER to Restraint Systems.

No
GO to AN6.

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AN6 CHECK CUSHION BLOWER CIRCUITS FOR AN OPEN


- Measure the resistance between:
- DCSM C3265c-16, circuit CHS03 (GN/BN), harness side and cushion TED C3035-2, circuit CHS03 (GN/BN), harness side.
- DCSM C3265c-15, circuit RHS03 (GY/OG), harness side and cushion TED C3035-4, circuit RHS03 (GY/OG), harness side.




- Are the resistances less than 5 ohms?

Yes
GO to AN7.

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

DISCONNECT the battery ground cable.

CONNECT passenger safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3133.

CONNECT driver safety belt buckle pretensioner C3065.

CONNECT driver seat side air bag module C3134.

REPOWER the SRS. REFER to Restraint Systems.

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AN7 CHECK BACKREST BLOWER CIRCUITS FOR AN OPEN


- Measure the resistance between:
- DCSM C3265c-16, circuit CHS03 (GN/BN), harness side and backrest TED C3034-2, circuit CHS03 (GN/BN), harness side.
- DCSM C3265c-15, circuit RHS03 (GY/OG), harness side and cushion TED C3034-4, circuit RHS03 (GY/OG), harness side.




- Are the resistances less than 5 ohms?

Yes
GO to AN8.

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

DISCONNECT the battery ground cable.

CONNECT passenger safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3133.

CONNECT driver safety belt buckle pretensioner C3065.

CONNECT driver seat side air bag module C3134.

REPOWER the SRS. REFER to Restraint Systems.

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AN8 CHECK THE RESISTANCE OF CUSHION AND BACKREST TEDs


- 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 C3035 pin 2 and pin 4, component side.
- backrest TED C3034 pin 2 and pin 4, component side.




- Are the resistances between 4,000 ohms and 10,000 ohms?

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

DISCONNECT the battery ground cable.

CONNECT passenger safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3133.

CONNECT driver safety belt buckle pretensioner C3065.

CONNECT driver seat side air bag module C3134.

REPOWER the SRS. REFER to Restraint Systems.

No
If cushion TED resistance is not between 4,000 and 10,000 ohms, INSTALL a new cushion TED. REFER to Seat Cushion Thermo-Electric Device Seat Cushion Thermo-Electric Device. CLEAR the DTCs. REPEAT the self-test.

If backrest TED resistance is not between 4,000 and 10,000 ohms, INSTALL a new backrest TED. REFER to Seat Backrest Thermo-Electric Device Seat Backrest Thermo-Electric Device. CLEAR the DTCs. REPEAT the self-test.

DISCONNECT the battery ground cable.

CONNECT passenger safety belt buckle pretensioner C3066.

CONNECT passenger seat side air bag module C3133.

CONNECT driver safety belt buckle pretensioner C3065.

CONNECT driver seat side air bag module C3134.

REPOWER the SRS. REFER to Restraint Systems.

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