Part 2
Seats
Pinpoint Test BO: DTC B272C
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) on an affected seat are reporting very different temperatures to the PCSM-2 (Passenger Climate Controlled Seat Module - 2). This may result from an airflow restriction or a circuit fault of either TED (Thermo-Electric Device) area. 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 B272C (Driver Differential Temperature Fault)- If there is a temperature differential between the LH rear seat 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 LH 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 LH 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 BO : DTC B272C
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.
BO17 CHECK THERMISTOR CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365B-7, circuit VHS42 (GN), harness side and ground.
Is the resistance greater than 10,000 ohms?
Yes
GO to BO18.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
BO18 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-7, circuit VHS42 (GN), harness side and PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365B-8, circuit RHS42 (BN/WH), 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 BO19.
BO19 CHECK THE TED (Thermo-Electric Device) THERMISTOR RESISTANCE
- Disconnect: Cushion TED (Thermo-Electric Device) C3358.
- 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.
BO20 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 BO21.
No
CORRECTLY INSTALL the backrest TED (Thermo-Electric Device) or INSTALL a new seat backrest foam pad.
INSTALL the seat. REFER to Seat - Second Row .
CLEAR the DTCs. REPEAT the self-test.
BO21 CHECK CUSHION TED (Thermo-Electric Device) CIRCUIT FOR A SHORT TO VOLTAGE
- 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-H, circuit RHS39 (VT/OG), harness side and ground.
Is any voltage present?
Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
No
GO to BO22.
BO22 CHECK CUSHION TED (Thermo-Electric Device) VOLTAGE CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365A-G, circuit CHS39 (GN/BU), harness side and ground.
Is the resistance greater than 10,000 ohms?
Yes
GO to BO23.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
BO23 CHECK THE RESISTANCE OF THE CUSHION TED (Thermo-Electric Device) AND WIRING
- Measure the resistance between PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365A-G circuit CHS39 (GN/BU), harness side and PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365A-H, circuit RHS39 (VT/OG), harness side.
Is the resistance between 0.9 and 10 ohms?
Yes
GO to BO25.
No
GO to BO24.
BO24 CHECK THE CUSHION TED (Thermo-Electric Device) RESISTANCE
- Disconnect: Cushion TED (Thermo-Electric Device) C3358.
- Measure the resistance between cushion TED (Thermo-Electric Device) C3358 pin 1 and pin 3, component side.
Is the resistance between 0.9 and 10 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.
BO25 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-16, circuit CHS67 (VT/BN), harness side and ground.
- PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C-12, circuit VHS68 (BN/GN), 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 BO26.
BO26 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-16, circuit CHS67 (VT/BN), harness side and ground.
- PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C-12, circuit VHS68 (BN/GN), harness side and ground.
Are the resistances greater than 10,000 ohms?
Yes
GO to BO27.
No
REPAIR the circuit(s). CLEAR the DTCs. REPEAT the self-test.
BO27 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-16, circuit CHS67 (VT/BN) and the negative lead to PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C-15, circuit RHS67 (WH/BU) 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-16, circuit CHS67 (VT/BN), harness side and PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C-15, circuit RHS67 (WH/BU), harness side.
Is the resistance between 4,000 ohms and 10,000 ohms?
Yes
GO to BO29.
No
GO to BO28.
BO28 CHECK THE BLOWER RESISTANCE
- Disconnect: Backrest TED (Thermo-Electric Device) C3362.
- 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) C3362 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.
BO29 CHECK THE BLOWER SPEED CONTROL AND CIRCUIT RESISTANCE
- NOTE: The ohmmeter must be connected with the positive lead to C3365C-12, circuit VHS68 (BN/GN), harness side and the negative lead to C3365C-15, circuit RHS67 (WH/BU), 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-12, circuit VHS68 (BN/GN) harness side and PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365C-15, circuit RHS67 (WH/BU), harness side.
Is the resistance between 240K ohms and 4M ohms?
Yes
GO to BO31.
No
GO to BO30.
BO30 CHECK THE BLOWER SPEED CONTROL RESISTANCE
- Disconnect: Backrest TED (Thermo-Electric Device) C3362.
- 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) C3362 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.
BO31 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-9, circuit VHS66 (GN/OG), harness side and ground.
Is any voltage present?
Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
No
GO to BO32.
BO32 CHECK THERMISTOR CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365B.
- Measure the resistance between PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365B-9, circuit VHS66 (GN/OG), harness side and ground.
Is the resistance greater than 10,000 ohms?
Yes
GO to BO33.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
BO33 CHECK THE TED (Thermo-Electric Device) THERMISTOR AND WIRING RESISTANCE
- Measure the resistance between PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365B-9, circuit VHS66 (GN/OG), harness side and PCSM-2 (Passenger Climate Controlled Seat Module - 2) C3365B-10, circuit RHS66 (GY/YE), 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 BO34.
BO34 CHECK THE TED (Thermo-Electric Device) THERMISTOR RESISTANCE
- Disconnect: Backrest TED (Thermo-Electric Device) C3362.
- 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.