Part 1
Seats
Pinpoint Test BP: DTC B272D
Normal Operation
The Passenger Climate Controlled Seat Module - 2 (PCSM-2) 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) are reporting different temperatures to the PCSM-2 (Passenger Climate Controlled Seat Module - 2). This may be caused by airflow restriction or a circuit fault of either TED (Thermo-Electric Device). 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 B272D (Passenger Differential Temperature Fault)- If there is a temperature differential between the RH rear backrest and cushion TED (Thermo-Electric Device) of 60°C (108°F) or more for more 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 PCSM-2 (Passenger Climate Controlled Seat Module - 2) puts the RH rear 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 PCSM-2 (Passenger Climate Controlled Seat Module - 2) will shut down the RH rear 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
- PCSM-2 (Passenger Climate Controlled Seat Module - 2)
PINPOINT TEST BP : DTC B272D
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.
BP1 CHECK PCSM-2 (Passenger Climate Controlled Seat Module - 2) FOR DTCs
- Enter the following diagnostic mode on the scan tool: Self Test- PCSM-2 (Passenger Climate Controlled Seat Module - 2).
Was DTC B272A or B272B retrieved?
Yes
For DTC B272A, GO to Pinpoint Test AQ. For DTC B272B, GO to Pinpoint Test AR. Pinpoint Test AQ: DTC B272A Pinpoint Test AR: DTC B272B
No
GO to BP2.
BP2 MONITOR PCSM-2 (Passenger Climate Controlled Seat Module - 2) TED (Thermo-Electric Device) TEMPERATURE PIDs
- Enter the following diagnostic mode on the scan tool: DataLogger- PCSM-2 (Passenger Climate Controlled Seat Module - 2)- PIDs.
- Passenger cushion thermal electric device (TED) temperature (PCSHTMP)
- Passenger back TED temperature (PBKTMP)
- Seat cushion thermal electric device temperature (CSHTEMP)
- Seat back thermal electric device temperature (BK_TEMP)
- NOTE: Make sure the temperature of the climate controlled seats has stabilized before monitoring the PIDs. Not allowing stabilization can cause incorrect readings and lead to incorrect identification of components that are not faulty.
Monitor the TED (Thermo-Electric Device) temperature PIDs with the climate controlled seats OFF. Compare the PIDs of the RH seat to those of the LH seat, this can help identify if there is a concern with the RH seat cushion or backrest PID readings.
Are both RH seat TED (Thermo-Electric Device) temperature PIDs within 10°C (18°F) of the ambient temperature?
Yes
GO to BP3.
No
If the RH seat cushion PID varies 10°C (18°F) or more from ambient temperature, GO to BP16.
If the RH seat backrest PID varies 10°C (18°F) or more from ambient temperature, GO to BP32.
BP3 CONFIRM FAULT IS IN THE SEAT CUSHION OR BACKREST
- Ignition OFF.
- Ignition ON.
- NOTE: A crushed seat cushion foam pad or a crushed climate controlled seat manifold (part of foam pad) 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.
After cycling the ignition and with the engine running, set the RH seat to high heat (3 indicators illuminated). Allow the seat to heat for at least 15 minutes while monitoring the TED (Thermo-Electric Device) temperature PIDs of the RH seat.
Do the RH seat cushion TED (Thermo-Electric Device) and backrest TED (Thermo-Electric Device) PIDs vary more than 60°C (108°F) from each other?
Yes
If the RH seat cushion PID is 60°C (108°F) hotter than the backrest PID, GO to BP5.
If the RH seat backrest PID is 60°C (108°F) hotter than the cushion PID, GO to BP20.
No
GO to BP4.
BP4 CHECK TEDs (Thermo-Electric Devices) COOLING PERFORMANCE
- Check TEDs (Thermo-Electric Devices) cooling performance on the affected seat. Refer to Component Test- Thermo-Electric Device (TED) Cooling Performance. Component Tests and General Diagnostics
Did the TEDs (Thermo-Electric Devices) pass the component test?
Yes
The DTC may have been set by extreme cabin temperatures or excessive sunload on the seat causing the system to enter recovery mode. Occupant size and weight characteristics can also be a factor. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. If a concern cannot be found or duplicated, RETURN the vehicle to the customer.
No
CHECK the affected seat cushion or backrest for correct installation of the climate controlled seat components (TED (Thermo-Electric Device), air ducts and foam pad). CHECK for airflow restrictions (TED (Thermo-Electric Device) inlets and outlets, TED (Thermo-Electric Device) -to-foam pad connections, filters and ducts) and REPAIR as needed. CHECK for an intermittent wiring fault. REPAIR as needed. CLEAR the DTCs. REPEAT the self-test.
BP5 CHECK FOR CORRECT TED (Thermo-Electric Device) INSTALLATION AND FOR CRUSHED FOAM
- Ignition OFF.
- Remove the seat. Refer to Seat- Second Row .
- Remove the seat cushion trim cover. Refer to Seat Cushion Cover- Second Row, 40 Percent or Seat Cushion Cover- Second Row, 60 Percent .
- Inspect the seat cushion for the following:
- Is the cushion blower obstructed?
- Is the blower filter restricted or plugged?
- Is the TED (Thermo-Electric Device) correctly installed?
- Is the seat cushion foam pad crushed or restricted?
Is the TED (Thermo-Electric Device) correctly installed and foam pad OK?
Yes
GO to BP6.
No
CORRECTLY INSTALL the cushion TED (Thermo-Electric Device) or INSTALL a new seat cushion foam pad.
INSTALL the seat. REFER to Seat - Second Row .
CLEAR the DTCs. REPEAT the self-test.
BP6 CHECK BACKREST TED (Thermo-Electric Device) - CIRCUIT FOR A SHORT TO VOLTAGE
- Position the RH seat in the vehicle and connect the seat-to-floor connectors.
- Disconnect: PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365A.
- Ignition ON.
- Measure the voltage between PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365A-D, circuit RHS44 (BU/WH), harness side and ground.
Is any voltage present?
Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
No
GO to BP7.
BP7 CHECK BACKREST TED (Thermo-Electric Device) CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365A-C, circuit CHS44 (GN/VT), harness side and ground.
Is the resistance greater than 10,000 ohms?
Yes
GO to BP8.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
BP8 CHECK THE RESISTANCE OF THE BACKREST TED (Thermo-Electric Device) AND WIRING
- Measure the resistance between PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365A-C, circuit CHS44 (GN/VT), harness side and PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365A-D, circuit RHS44 (BU/WH), harness side.
Is the resistance between 0.9 and 10 ohms?
Yes
GO to BP10.
No
GO to BP9.
BP9 CHECK THE RESISTANCE OF THE BACKREST TED (Thermo-Electric Device)
- Disconnect: Backrest TED (Thermo-Electric Device) C3361.
- Measure the resistance between backrest TED (Thermo-Electric Device) C3361 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.
No
INSTALL a new backrest TED (Thermo-Electric Device). REFER to Seat Backrest Thermo-Electric Device - Second Row . CLEAR the DTCs. REPEAT the self-test.
BP10 CHECK BLOWER CIRCUIT AND SPEED CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C.
- Ignition ON.
- Measure the voltage between:
- PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C-8, circuit CHS63 (VT), harness side and ground.
- PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C-3, circuit VHS65 (VT/WH), harness side and ground.
Is voltage present on either circuit?
Yes
REPAIR the circuit(s). CLEAR the DTCs. REPEAT the self-test.
No
GO to BP11.
BP11 CHECK BLOWER AND SPEED CONTROL CIRCUITS FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between:
- PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C-8, circuit CHS63 (VT), harness side and ground.
- PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C-3, circuit VHS65 (VT/WH), harness side and ground.
Are the resistances greater than 10,000 ohms?
Yes
GO to BP12.
No
REPAIR the circuit(s). CLEAR the DTCs. REPEAT the self-test.
BP12 CHECK THE BLOWER AND WIRING RESISTANCE
- NOTE: The ohmmeter must be connected with the positive lead to PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C-8, circuit CHS63 (VT) and the negative lead to PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C-7, circuit RHS63 (WH/GN) 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 PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C-8, circuit CHS63 (VT), harness side and PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C-7, circuit RHS63 (WH/GN), harness side.
Is the resistance between 4,000 ohms and 10,000 ohms?
Yes
GO to BP14.
No
GO to BP13.
BP13 CHECK THE BLOWER RESISTANCE
- Disconnect: Cushion TED (Thermo-Electric Device) C3359.
- 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) C3359 pin 2 and pin 4, component side.
Is the resistance between 4,000 ohms and 10,000 ohms?
Yes
REPAIR the circuit(s). CLEAR the DTCs. REPEAT the self-test.
No
INSTALL a new cushion TED (Thermo-Electric Device). REFER to Seat Cushion Thermo-Electric Device - Second Row . CLEAR the DTCs. REPEAT the self-test.
BP14 CHECK THE BLOWER SPEED CONTROL AND CIRCUIT RESISTANCE
- NOTE: The ohmmeter must be connected with the positive lead to C3365C-3, circuit VHS65 (VT/WH), harness side and the negative lead to C3365C-7, circuit RHS63 (WH/GN), 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 PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C-3, circuit VHS65 (VT/WH), harness side and PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C-7, circuit RHS63 (WH/GN), harness side.
Is the resistance between 240K ohms and 4M ohms?
Yes
GO to BP16.
No
GO to BP15.
BP15 CHECK THE BLOWER SPEED CONTROL RESISTANCE
- Disconnect: Cushion TED (Thermo-Electric Device) C3359.
- 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 cushion TED (Thermo-Electric Device) C3359 pin 7 and pin 4, component side.
Is the resistance between 240K ohms and 4M ohms?
Yes
REPAIR the circuit(s). CLEAR the DTCs. REPEAT the self-test.
No
INSTALL a new cushion TED (Thermo-Electric Device). REFER to Seat Cushion Thermo-Electric Device - Second Row . CLEAR the DTCs. REPEAT the self-test.
BP16 CHECK THERMISTOR CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365B.
- Ignition ON.
- Measure the voltage between PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365B-2, circuit VHS45 (GY/BN), harness side and ground.
Is any voltage present?
Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
No
GO to BP17.