Pinpoint Test BS: DTC B2730
Seats
Pinpoint Tests
Pinpoint Test BS: DTC B2730
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.
The presence of overtemperature faults (DTCs B2729, B2730, B272A and B272B) can be induced by incorrect operation of the climate controlled seat system after an initial heat setting has been attained. If a heat setting is repeatedly turned OFF and ON in an attempt to increase the seat temperature or repeatedly toggled between heat and cool modes, an overtemperature condition can result and the DTCs will be set.
- DTC B2730 (Back Over-Temp Detected) (Driver) - For heat mode, if the driver seat backrest TED temperature exceeds 110°C (230°F) continuously for more than 4 seconds in any heat mode, the DCSM turns off the TED and enters a fan only state to recover from the over-temperature condition (recovery mode). If the TED temperature does not recover after 30 seconds, the DTC will set and the seat is disabled. If the TED does recover, the TED is re-enabled, the system continues to operate normally and the DTC will not be set. If the over-temperature condition occurs a second time within the same ignition cycle, the DTC will set and the seat is disabled.
- DTC B2730 (Back Over-Temp Detected) (Driver) - For cool mode, if the driver seat backrest TED temperature exceeds 65°C (149°F) continuously for more than 4 seconds in any cool mode, the DCSM turns off the TED and enters a fan only state to recover from the over-temperature condition (recovery mode). If the TED temperature does not recover after 5 minutes, the DTC will set and the seat is disabled. If the TED does recover, the TED is re-enabled, the system continues to operate normally and the DTC will not be set. If the over-temperature condition occurs a second time within the same ignition cycle, the DTC will set and the seat is disabled.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Restricted backrest TED filter
- Crushed or restricted backrest foam pad
- Backrest TED assembly
- PCSM-2
PINPOINT TEST BS: DTC B2730
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.
NOTE: The presence of overtemperature faults (DTCs B2729, B2730, B272A and B272B) can be induced by incorrect operation of the climate controlled seat system after an initial heat setting has been attained. If a heat setting is repeatedly turned OFF and ON in an attempt to increase the seat temperature or repeatedly toggled between heat and cool modes, an overtemperature condition can result and the DTCs will be set.
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BS1 CHECK FOR PCSM-2 DTCs
- Enter the following diagnostic mode on the scan tool: Self Test - PCSM-2.
- Was DTC B2730 retrieved?
Yes
GO to BS2.
No
GO to BS4.
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BS2 CHECK TED THERMISTOR CIRCUITS FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: PCSM-2 C3365B.
- Disconnect: Backrest TED C3362.
- Measure the resistance between:
- PCSM-2 C3365B-9, circuit VHS66 (GN/OG), harness side and ground.
- PCSM-2 C3365B-10, circuit RHS66 (GY/YE), harness side and ground.
- Are the resistances greater than 10,000 ohms?
Yes
GO to BS3.
No
REPAIR the circuit(s). CLEAR the DTCs. REPEAT the self-test.
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BS3 CHECK THE TED THERMISTOR RESISTANCE
- Measure the resistance between backrest TED C3362 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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BS4 CONFIRM THE FAULT
- Verify with the customer that the concern is the seat shuts OFF in heat mode.
- NOTE: A crushed seat backrest 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.
- Attempt to recreate the fault. Start the vehicle and set the LH seat to high heat for at least 15 minutes.
- Is the customer concern with the seat shutting OFF in heat mode or was the fault recreated?
Yes
GO to BS5.
No
Fault not present. Fault may have been set due to a past failure or incorrect use of the climate controlled seat system by repeated switching between HEAT and COOL modes. CLEAR the DTCs. REPEAT the self-test.
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BS5 CHECK OPERATION OF THE SEAT
- Start the engine.
- With the engine running, set both seats to high cool (3 indicators illuminated).
- Compare the airflow from the LH seat backrest to the airflow from the RH seat backrest.
- Is the airflow exhausting from the LH seat backrest comparable to the airflow exhausting from the RH seat backrest?
Yes
GO to BS14.
No
GO to BS6.
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BS6 CHECK BACKREST BLOWER FOR AN OBSTRUCTION OR RESTRICTED FILTER
- Ignition OFF.
- Inspect the blower of the backrest TED assembly for an obstruction or for a restricted filter.
- Is the blower clear of any obstruction and the filter clean?
Yes
GO to BS7.
No
REMOVE the obstruction or INSTALL a new filter. CLEAR the DTCs. REPEAT the self-test.
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BS7 CHECK BACKREST FAN OPERATION
- Start the engine.
- With the engine running, set both seats to high cool (3 indicators illuminated).
- Inspect the backrest blower for operation.
- Does the backrest blower operate?
Yes
GO to BS14.
No
GO to BS8.
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BS8 CHECK BLOWER SPEED CONTROL CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: PCSM-2 C3365C.
- Disconnect: Backrest TED C3362.
- Measure the resistance between PCSM-2 C3365C-12, circuit VHS68 (BN/GN), harness side and backrest TED C3362-7, circuit VHS68 (BN/GN), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to BS9.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
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BS9 CHECK BLOWER CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure the voltage between PCSM-2 C3365C-15, circuit RHS67 (WH/BU), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
No
GO to BS10.
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BS10 CHECK BLOWER CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between PCSM-2 C3365C-16, circuit CHS67 (VT/BN), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to BS11.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
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BS11 CHECK BLOWER CIRCUITS FOR AN OPEN
- Measure the resistance between:
- PCSM-2 C3365C-16, circuit CHS67 (VT/BN), harness side and backrest TED C3362-2, circuit CHS67 (VT/BN), harness side.
- PCSM-2 C3365C-15, circuit RHS67 (WH/BU), harness side and backrest TED C3362-4, circuit RHS67 (WH/BU), harness side.
- Are the resistances less than 5 ohms?
Yes
GO to BS12.
No
REPAIR the circuit(s). CLEAR the DTCs. REPEAT the self-test.
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BS12 CHECK THE BLOWER RESISTANCE
- 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
GO to BS13.
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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BS13 CHECK THE BLOWER SPEED CONTROL RESISTANCE
- 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
GO to BS14.
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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BS14 CHECK FOR CORRECT TED INSTALLATION AND FOR CRUSHED FOAM
- 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 TED correctly installed?
- Is the seat backrest foam pad crushed or restricted?
- Is the TED correctly installed and foam pad OK?
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
CORRECTLY INSTALL the backrest TED or INSTALL a new seat backrest foam pad. 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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