Part 2
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.
BP17 CHECK THERMISTOR CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365B-2, circuit VHS45 (GY/BN), harness side and ground.
Is the resistance greater than 10,000 volts?
Yes
GO to BP18.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
BP18 CHECK THE TED (Thermo-Electric Device) THERMISTOR AND WIRING RESISTANCE
- Measure the resistance between PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365B-2, circuit VHS45 (GY/BN), harness side and PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365B-3, circuit RHS45 (YE/GN), 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 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
GO to BP19.
BP19 CHECK THE TED (Thermo-Electric Device) THERMISTOR RESISTANCE
- Disconnect: Cushion TED (Thermo-Electric Device) C3359.
- 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.
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.
BP20 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 backrest trim cover. Refer to Seat Backrest Cover- Second Row, 40 Percent or Seat Backrest Cover- Second Row, 60 Percent .
- 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 BP21.
No
CORRECTLY INSTALL the backrest TED (Thermo-Electric Device) or INSTALL a new seat backrest foam pad. REFER to Seat Backrest Thermo-Electric Device - Second Row . CLEAR the DTCs. REPEAT the self-test.
INSTALL the seat. REFER to Seat - Second Row .
CLEAR the DTCs. REPEAT the self-test.
BP21 CHECK CUSHION 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-B, circuit RHS43 (VT/GY), harness side and ground.
Is any voltage present?
Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
No
GO to BP22.
BP22 CHECK CUSHION 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-A, circuit CHS43 (GY/BU), harness side and ground.
Is the resistance greater than 10,000 ohms?
Yes
GO to BP23.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
BP23 CHECK THE CUSHION TED (Thermo-Electric Device) AND WIRING RESISTANCE
- Measure the resistance between PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365A-A circuit CHS43 (GY/BU), harness side and PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365A-B, circuit RHS43 (VT/GY), harness side.
Is the resistance between 0.9 and 10 ohms?
Yes
GO to BP25.
No
GO to BP24.
BP24 CHECK THE CUSHION TED (Thermo-Electric Device) RESISTANCE
- Disconnect: Cushion TED (Thermo-Electric Device) C3359.
- Measure the resistance between cushion TED (Thermo-Electric Device) C3359 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 cushion TED (Thermo-Electric Device). REFER to Seat Cushion Thermo-Electric Device - Second Row . CLEAR the DTCs. REPEAT the self-test.
BP25 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-4, circuit VHS64 (BN/VT), 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 BP26.
BP26 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-4, circuit VHS64 (BN/VT), harness side and ground.
Are the resistances greater than 10,000 ohms?
Yes
GO to BP27.
No
REPAIR the circuit(s). CLEAR the DTCs. REPEAT the self-test.
BP27 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 BP29.
No
GO to BP28.
BP28 CHECK THE BLOWER RESISTANCE
- Disconnect: Backrest TED (Thermo-Electric Device) C3361.
- 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) C3361 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 backrest TED (Thermo-Electric Device). REFER to Seat Backrest Thermo-Electric Device - Second Row . CLEAR the DTCs. REPEAT the self-test.
BP29 CHECK THE BLOWER SPEED CONTROL AND CIRCUIT RESISTANCE
- NOTE: The ohmmeter must be connected with the positive lead to C3365C-4, circuit VHS64 (BN/VT), 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-4, circuit VHS64 (BN/VT), 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 BP31.
No
GO to BP30.
BP30 CHECK THE BLOWER SPEED CONTROL RESISTANCE
- Disconnect: Backrest TED (Thermo-Electric Device) C3361.
- 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) C3361 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 backrest TED (Thermo-Electric Device). REFER to Seat Backrest Thermo-Electric Device - Second Row . CLEAR the DTCs. REPEAT the self-test.
BP31 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-4, circuit VHS62 (GN/WH), harness side and ground.
Is any voltage present?
Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
No
GO to BP32.
BP32 CHECK THERMISTOR CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365B-4, circuit VHS62 (GN/WH), harness side and ground.
Is the resistance greater than 10,000 ohms?
Yes
GO to BP33.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
BP33 CHECK THE TED (Thermo-Electric Device) THERMISTOR AND WIRING RESISTANCE AT THE PCSM-2 (Passenger Climate Controlled Seat Module - 2)
- Measure the resistance between PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365B-4, circuit VHS62 (GN/WH), harness side and PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365B-5, circuit RHS62 (GY), 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 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
GO to BP34.
BP34 CHECK THE TED (Thermo-Electric Device) THERMISTOR RESISTANCE
- Disconnect: Backrest TED (Thermo-Electric Device) C3361.
- 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
Is the resistance within the limits indicated?
Yes
REPAIR the circuit(s). 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.