Pinpoint Test BQ: DTC B272E
Seats
Pinpoint Test BQ: DTC B272E
Normal Operation
The Passenger Climate Controlled Seat Module - 2 (PCSM-2) supplies voltage and ground to both blowers in parallel circuits. If the DCSM (Dual Climate Controlled Seat Module) detects any of the faults below, the DTC will be set.
- 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 PCSM-2 (Passenger Climate Controlled Seat Module - 2) disables outputs to the LH rear seat. The DTC will also set if the blower voltage supply or return circuit is open to only one blower when PCSM-2 (Passenger Climate Controlled Seat Module - 2) supply voltage is less than 12 volts.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Rear Heating Ventilation Air Conditioning (RHVAC) module
- Backrest or cushion Thermo-Electric Device (TED)
- PCSM-2 (Passenger Climate Controlled Seat Module - 2)
PINPOINT TEST BQ : DTC B272E
NOTICE: When taking measurements at Passenger Climate Controlled Seat Module - 2 (PCSM-2) 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.
BQ1 CHECK PCSM-2 (Passenger Climate Controlled Seat Module - 2) CLIMATE-CONTROLLED SEAT HEAT COMMAND (TED_HEAT_D) PID
- Access the cushion and backrest TEDs (Thermo-Electric Devices) and remove the filters to watch the TED (Thermo-Electric Device) fans.
- Enter the following diagnostic mode on the scan tool: DataLogger- PCSM-2 (Passenger Climate Controlled Seat Module - 2)- PID: TED_HEAT_D.
- NOTE: The PCSM-2 (Passenger Climate Controlled Seat Module - 2) 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 (Thermo-Electric Devices) for fan movement.
Did both fans turn on?
Yes
INSTALL a new RHVAC (Rear Heating Ventilation Air Conditioning) module.
No
GO to BQ2.
BQ2 CHECK FOR AN INTERMITTENT CONNECTION AT THE PCSM-2 (Passenger Climate Controlled Seat Module - 2)
- Ignition OFF.
- Disconnect: PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C.
- Connect: PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C.
- With the engine running, turn the LH climate controlled seat system on while monitoring the cushion and backrest fans for movement.
- If there is fan movement, run the LH 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 C3365C and REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
No
GO to BQ3.
BQ3 CHECK FOR AN INTERMITTENT CONNECTION AT THE CUSHION TED (Thermo-Electric Device)
- Ignition OFF.
- Disconnect: Cushion TED (Thermo-Electric Device) C3358.
- Connect: Cushion TED (Thermo-Electric Device) C3358.
- With the engine running, turn the LH climate controlled seat system on while monitoring the cushion and backrest fans for movement.
- If there is fan movement, run the LH 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 C3358 and REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
No
GO to BQ4.
BQ4 CHECK FOR AN INTERMITTENT CONNECTION AT THE BACKREST TED (Thermo-Electric Device)
- Ignition OFF.
- Disconnect: Backrest TED (Thermo-Electric Device) C3362.
- Connect: Backrest TED (Thermo-Electric Device) C3362.
- With the engine running, turn the LH climate controlled seat system on while monitoring the cushion and backrest fans for movement.
- If there is fan movement, run the LH 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 C3362 and REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
No
GO to BQ5.
BQ5 CHECK BLOWER CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C.
- Disconnect: Cushion TED (Thermo-Electric Device) C3358.
- Disconnect: Backrest TED (Thermo-Electric Device) C3362.
- Ignition ON.
- Measure the voltage between PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C-16, circuit CHS67 (VT/BN), harness side and ground.
Is any voltage present?
Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
No
GO to BQ6.
BQ6 CHECK CUSHION BLOWER CIRCUITS FOR AN OPEN
- Measure the resistance between:
- PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C-16, circuit CHS67 (VT/BN), harness side and cushion TED (Thermo-Electric Device) C3358-2, circuit CHS67 (VT/BN), harness side.
- PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C-15, circuit RHS67 (WH/BU), harness side and cushion TED (Thermo-Electric Device) C3358-4, circuit RHS67 (WH/BU), harness side.
Are the resistances less than 5 ohms?
Yes
GO to BQ7.
No
REPAIR the circuit(s). CLEAR the DTCs. REPEAT the self-test.
BQ7 CHECK BACKREST BLOWER CIRCUITS FOR AN OPEN
- Measure the resistance between:
- PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C-16, circuit CHS67 (VT/BN), harness side and backrest TED (Thermo-Electric Device) C3362-2, circuit CHS67 (VT/BN), harness side.
- PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C-15, circuit RHS67 (WH/BU), harness side and cushion TED (Thermo-Electric Device) C3362-4, circuit RHS67 (WH/BU), harness side.
Are the resistances less than 5 ohms?
Yes
GO to BQ8.
No
REPAIR the circuit(s). CLEAR the DTCs. REPEAT the self-test.
BQ8 CHECK THE RESISTANCE OF CUSHION AND BACKREST TEDs (Thermo-Electric Devices)
- 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 (Thermo-Electric Device) C3358 pin 2 and pin 4, component side.
- backrest TED (Thermo-Electric Device) C3362 pin 2 and pin 4, component side.
Are the resistances between 4,000 ohms and 10,000 ohms?
Yes
INSTALL a new PCSM-2 (Passenger Climate Controlled Seat Module - 2). REFER to Passenger Climate - Controlled Seat Module (PCSM-2) . CLEAR the DTCs. REPEAT the self-test.
No
If cushion TED (Thermo-Electric Device) resistance is not between 4,000 and 10,000 ohms, INSTALL a new cushion TED (Thermo-Electric Device). REFER to Seat Cushion Thermo-Electric Device - Second Row . CLEAR the DTCs. REPEAT the self-test.
If backrest TED (Thermo-Electric Device) resistance is not between 4,000 and 10,000 ohms, INSTALL a new backrest TED (Thermo-Electric Device). REFER to Seat Backrest Thermo-Electric Device - Second Row . CLEAR the DTCs. REPEAT the self-test.