Pinpoint Tests BO: DTC B272C
Seats
Pinpoint Test BO: DTC B272C
Refer to Wiring Diagram Set 119, Climate Controlled Seats for schematic and connector information. Diagrams By Number
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. This may result from an airflow restriction or a circuit fault of either TED area. If a TED and manifold is clear of obstruction and is operational, the other TED and circuitry on the seat should be checked. It is important to note that a TED with a higher temperature may be operating correctly and not the area of concern. The other TED 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 of 60°C (108°F) or more for more than 4 seconds, the TED is disconnected or the duct is blocked, this DTC will set. When this happens the first time in a key cycle, the PCSM-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 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 filter
- Crushed or restricted cushion or backrest foam pad
- Cushion or backrest TED assembly
- PCSM-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.
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BO1 CHECK FOR PCSM-2 DTCs
- Enter the following diagnostic mode on the scan tool: Self Test - PCSM-2.
- Was DTC B2729 or B2730 retrieved?
Yes
For DTC B2729, GO to Pinpoint Test AP. For DTC B2730, GO to Pinpoint Test AW. Pinpoint Tests AP: DTC B2729 Pinpoint Tests AW: DTC B2730
No
GO to BO2.
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BO2 MONITOR PCSM-2 TED TEMPERATURE PIDs
- Enter the following diagnostic mode on the scan tool: DataLogger - PCSM-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 TED temperature PIDs with the climate controlled seats OFF. Compare the PID values of the LH seat to those of the RH seat, this can help identify if there is a concern with the LH seat cushion or backrest PID value readings.
- Are both LH seat TED temperature PIDs within 10°C (18°F) of the ambient temperature?
Yes
GO to BO3.
No
If the LH seat cushion PID varies 10°C (18°F) or more from ambient temperature, GO to BO16.
If the LH seat backrest PID varies 10°C (18°F) or more from ambient temperature, GO to BO32.
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BO3 CONFIRM THE FAULT IS IN THE SEAT CUSHION OR THE 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 LH seat to high heat (3 indicators illuminated). Allow the seat to heat for at least 15 minutes while monitoring the TED temperature PIDs of the LH seat.
- Do the LH seat cushion TED and backrest TED PIDs vary more than 60°C (108°F) from each other?
Yes
If the LH seat cushion PID is 60°C (108°F) hotter than the backrest PID, GO to BO5.
If the LH seat backrest PID is 60°C (108°F) hotter than the cushion PID, GO to BO20.
No
GO to BO4.
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BO4 CHECK THE TEDs COOLING PERFORMANCE
- Check the TEDs cooling performance on the affected seat. Refer to Component Test - Thermo-Electric Device (TED) Cooling Performance. Component Tests and General Diagnostics
- Did the TEDs 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, air ducts and foam pad). CHECK for airflow restrictions (TED inlets and outlets, TED-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.
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BO5 CHECK FOR CORRECT TED INSTALLATION AND FOR CRUSHED FOAM
- Ignition OFF.
- Remove the seat. Refer to Seat - Second Row Seat - Second Row.
- Remove the seat cushion trim cover. Refer to Seat Cushion Cover - Second Row, Bucket Seat Cushion Cover - Second Row, Bucket.
- Inspect the seat cushion for the following:
- Is the cushion blower obstructed?
- Is the blower filter restricted or plugged?
- Is the TED correctly installed?
- Is the seat cushion foam pad crushed or restricted?
- Is the TED correctly installed and foam pad OK?
Yes
GO to BO6.
No
CORRECTLY INSTALL the cushion TED or INSTALL a new seat cushion foam pad.
INSTALL the seat. REFER to Seat - Second Row Seat - Second Row.
CLEAR the DTCs. REPEAT the self-test.
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BO6 CHECK BACKREST TED- CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: PCSM-2 C3365A.
- Ignition ON.
- Measure the voltage between PCSM-2 C3365A-K, circuit RHS40 (BU/BN), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
No
GO to BO7.
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BO7 CHECK BACKREST TED VOLTAGE CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between PCSM-2 C3365A-J, circuit CHS40 (GY/VT), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to BO8.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
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BO8 CHECK THE RESISTANCE OF THE BACKREST TED AND WIRING
- Measure the resistance between PCSM-2 C3365A-J, circuit CHS40 (GY/VT), harness side and PCSM-2 C3365A-K, circuit RHS40 (BU/BN), harness side.
- Is the resistance between 0.9 and 10 ohms?
Yes
GO to BO10.
No
GO to BO9.
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BO9 CHECK THE RESISTANCE OF THE BACKREST TED
- Disconnect: Backrest TED C3362.
- Measure the resistance between backrest TED C3362 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 backrest TED. REFER to Seat Backrest Thermo-Electric Device - Second Row Seat Backrest Thermo-Electric Device - Second Row. CLEAR the DTCs. REPEAT the self-test.
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BO10 CHECK BLOWER CIRCUIT AND SPEED CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: PCSM-2 C3365C.
- Ignition ON.
- Measure the voltage between:
- PCSM-2 C3365C-16, circuit CHS67 (VT/BN), harness side and ground.
- PCSM-2 C3365C-11, circuit VHS70 (YE), harness side and ground.
- Is voltage present on either circuit?
Yes
GO to BO11.
No
REPAIR the circuit(s). CLEAR the DTCs. REPEAT the self-test.
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BO11 CHECK BLOWER AND SPEED CONTROL CIRCUITS FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between:
- PCSM-2 C3365C-16, circuit CHS67 (VT/BN), harness side and ground.
- PCSM-2 C3365C-11, circuit VHS70 (YE), harness side and ground.
- Are the resistances greater than 10,000 ohms?
Yes
GO to BO12.
No
REPAIR the circuit(s). CLEAR the DTCs. REPEAT the self-test.
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BO12 CHECK THE BLOWER AND WIRING
- NOTE: The ohmmeter must be connected with the positive lead to PCSM-2 C3365C-16, circuit CHS67 (VT/BN) and the negative lead to PCSM-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 C3365C-16, circuit CHS67 (VT/BN), harness side and PCSM-2 C3365C-15, circuit RHS67 (WH/BU), harness side.
- Is the resistance between 4,000 ohms and 10,000 ohms?
Yes
GO to BO14.
No
GO to BO13.
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BO13 CHECK THE BLOWER RESISTANCE
- Disconnect: Cushion TED C3358.
- 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 C3358 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. REFER to Seat Cushion Thermo-Electric Device - Second Row Seat Cushion Thermo-Electric Device - Second Row. CLEAR the DTCs. REPEAT the self-test.
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BO14 CHECK THE BLOWER SPEED CONTROL AND CIRCUIT RESISTANCE
- NOTE: The ohmmeter must be connected with the positive lead to C3365C-11, circuit VHS70 (YE), 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 C3365C-11, circuit VHS70 (YE) harness side and PCSM-2 C3365C-15, circuit RHS67 (WH/BU), harness side.
- Is the resistance between 240K ohms and 4M ohms?
Yes
GO to BO16.
No
GO to BO15.
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BO15 CHECK THE BLOWER SPEED CONTROL RESISTANCE
- Disconnect: Cushion TED C3358.
- 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 C3358 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. REFER to Seat Cushion Thermo-Electric Device - Second Row Seat Cushion Thermo-Electric Device - Second Row. CLEAR the DTCs. REPEAT the self-test.
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BO16 CHECK THERMISTOR CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: PCSM-2 C3365B.
- Ignition ON.
- Measure the voltage between PCSM-2 C3365B-7, circuit VHS42 (GN), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
No
GO to BO17.
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BO17 CHECK THERMISTOR CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between PCSM-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.
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BO18 CHECK THE TED THERMISTOR AND WIRING RESISTANCE AT THE PCSM-2
- Measure the resistance between PCSM-2 C3365B-7, circuit VHS42 (GN), harness side and PCSM-2 C3365B-8, circuit RHS42 (BN/WH), harness side. Note the ambient temperature and compare result to the following table:
- Is the resistance within the limits indicated?
Yes
INSTALL a new PCSM-2. REFER to Passenger Climate - Controlled Seat Module (PCSM-2) Passenger Climate - Controlled Seat Module (PCSM-2). CLEAR the DTCs. REPEAT the self-test.
No
GO to BO19.
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BO19 CHECK THE TED THERMISTOR RESISTANCE
- Disconnect: Cushion TED C3358.
- Measure the resistance between cushion TED pin 5 and pin 8, component side. Note the ambient temperature and compare result to the following table:
- 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. REFER to Seat Cushion Thermo-Electric Device - Second Row Seat Cushion Thermo-Electric Device - Second Row. CLEAR the DTCs. REPEAT the self-test.
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BO20 CHECK FOR CORRECT TED INSTALLATION AND FOR CRUSHED FOAM
- Ignition OFF.
- Remove the seat. Refer to Seat - Second Row Seat - Second Row.
- Remove the seat backrest trim cover. Refer to Seat Backrest Cover - Second Row, Bucket Seat Backrest Cover - Second Row, Bucket.
- Inspect the seat backrest for the following:
- Is the backrest blower obstructed?
- Is the blower filter restricted or plugged?
- Is the TED correctly installed?
- Is the seat backrest foam pad crushed or restricted?
- Is the TED correctly installed and foam pad OK?
Yes
GO to BO21.
No
CORRECTLY INSTALL the backrest TED or INSTALL a new seat backrest foam pad.
INSTALL the seat. REFER to Seat - Second Row Seat - Second Row.
CLEAR the DTCs. REPEAT the self-test.
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BO21 CHECK CUSHION TED CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: PCSM-2 C3365A.
- Ignition ON.
- Measure the voltage between PCSM-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.
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BO22 CHECK CUSHION TED VOLTAGE CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between PCSM-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.
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BO23 CHECK THE RESISTANCE OF THE CUSHION TED AND WIRING
- Measure the resistance between PCSM-2 C3365A-G circuit CHS39 (GN/BU), harness side and PCSM-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.
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BO24 CHECK THE CUSHION TED RESISTANCE
- Disconnect: Cushion TED C3358.
- Measure the resistance between cushion TED 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. REFER to Seat Cushion Thermo-Electric Device - Second Row Seat Cushion Thermo-Electric Device - Second Row. CLEAR the DTCs. REPEAT the self-test.
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BO25 CHECK BLOWER CIRCUIT AND SPEED CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: PCSM-2 C3365C.
- Ignition ON.
- Measure the voltage between:
- PCSM-2 C3365C-16, circuit CHS67 (VT/BN), harness side and ground.
- PCSM-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.
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BO26 CHECK BLOWER AND SPEED CONTROL CIRCUITS FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between:
- PCSM-2 C3365C-16, circuit CHS67 (VT/BN), harness side and ground.
- PCSM-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.
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BO27 CHECK THE BLOWER AND WIRING RESISTANCE
- NOTE: The ohmmeter must be connected with the positive lead to PCSM-2 C3365C-16, circuit CHS67 (VT/BN) and the negative lead to PCSM-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 C3365C-16, circuit CHS67 (VT/BN), harness side and PCSM-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.
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BO28 CHECK THE BLOWER RESISTANCE
- Disconnect: Backrest TED 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 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. REFER to Seat Backrest Thermo-Electric Device - Second Row Seat Backrest Thermo-Electric Device - Second Row. CLEAR the DTCs. REPEAT the self-test.
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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 C3365C-12, circuit VHS68 (BN/GN) harness side and PCSM-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.
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BO30 CHECK THE BLOWER SPEED CONTROL RESISTANCE
- Disconnect: Backrest TED 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 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. REFER to Seat Backrest Thermo-Electric Device - Second Row Seat Backrest Thermo-Electric Device - Second Row. CLEAR the DTCs. REPEAT the self-test.
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BO31 CHECK THERMISTOR CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: PCSM-2 C3365B.
- Ignition ON.
- Measure the voltage between PCSM-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.
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BO32 CHECK THERMISTOR CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: PCSM-2 C3365B.
- Measure the resistance between PCSM-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.
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BO33 CHECK THE TED THERMISTOR AND WIRING RESISTANCE
- Measure the resistance between PCSM-2 C3365B-9, circuit VHS66 (GN/OG), harness side and PCSM-2 C3365B-10, circuit RHS66 (GY/YE), harness side. Note the ambient temperature and compare result to the following table:
- Is the resistance within the limits indicated?
Yes
INSTALL a new PCSM-2. REFER to Passenger Climate - Controlled Seat Module (PCSM-2) Passenger Climate - Controlled Seat Module (PCSM-2). CLEAR the DTCs. REPEAT the self-test.
No
GO to BO34.
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BO34 CHECK THE TED THERMISTOR RESISTANCE
- Disconnect: Backrest TED C3362.
- Measure the resistance between backrest TED pin 5 and pin 8, component side. Note the ambient temperature and compare result to the following table:
- 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. REFER to Seat Backrest Thermo-Electric Device - Second Row Seat Backrest Thermo-Electric Device - Second Row. CLEAR the DTCs. REPEAT the self-test.
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