Lexus NX: Front Left Seat Heat Sensor Circuit (B14C1)
DESCRIPTION
Output to the front seat cushion heater temperature sensor stops if one of the following occurs: 1) the temperature sensor is open or shorted; or 2) the temperature sensor is damaged and its output value does not change.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area |
|---|---|---|---|
| B14C1 | Front Left Seat Heat Sensor Circuit | Seat heater temperature sensor malfunction |
|
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
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If the auxiliary battery voltage is low, the seat heater system may not operate. When "High Power Consumption Partial Limit On AC/Heater Operation." is displayed on the multi-information display in the combination meter assembly, inspect the auxiliary battery, referring to On-vehicle Inspection for the charging system.
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HINT:
If the auxiliary battery voltage is low, "Operation Limitation Control History Count (Level 1)" and "Operation Limitation Control History Count (Level 2) is counted.
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If the auxiliary battery voltage is low, the seat heater system may not operate. Refer to Data List for the power steering system.
for Manual Tilt and Manual Telescopic Steering Column: Click here
for Power Tilt and Power Telescopic Steering Column: Click here
PROCEDURE
| 1. | CLEAR DTC |
(a) Clear the DTCs.
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| 2. | CHECK FOR DTC |
(a) Check for DTCs.
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OK:
DTC B14C1 is not output.
| OK | .gif) | USE SIMULATION METHOD TO CHECK |
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| 3. | READ VALUE USING TECHSTREAM (FL Seat Heater Temperature) |
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Body Electrical / Air Conditioner / Data List.
(e) Read the Data List according to the display on the Techstream.
Body Electrical > Air Conditioner > Data List| Tester Display | Measurement Item | Range | Normal Condition | Diagnostic Note |
|---|---|---|---|---|
| FL Seat Heater Temperature | Front seat LH heater temperature | -29.7°C to 59.55°C | Within range from 32 to 43°C (89 to 109°F) | Front seat heater is on |
| Tester Display |
|---|
| FL Seat Heater Temperature |
OK:
On the Techstream screen, the seat heater temperature is as specified in the normal condition column.
| OK | | REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY |
|
| 4. | INSPECT SEPARATE TYPE FRONT SEAT CUSHION COVER LH |
(a) Remove the separate type front seat cushion cover LH.
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(b) Inspect the separate type front seat cushion cover LH.
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| NG | | REPLACE SEPARATE TYPE FRONT SEAT CUSHION COVER LH |
|
| 5. | INSPECT SEAT HEATER CONTROL SUB-ASSEMBLY LH |
| (a) Disconnect the g5 and SHL seat heater control sub-assembly LH connectors. |
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(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| g5-5 (THR) - SHL-2 (TH1) | Always | Below 1 Ω |
| g5-5 (THR) or SHL-2 (TH1) - Body ground | Always | 10 kΩ or higher |
| g5-2 (PR) - SHL-3 (TH2) | Always | Below 1 Ω |
| g5-2 (PR) or SHL-3 (TH2) - Body ground | Always | 10 kΩ or higher |
| NG | | REPLACE SEAT HEATER CONTROL SUB-ASSEMBLY LH |
|
| 6. | CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - SEAT HEATER CONTROL SUB-ASSEMBLY LH) |
(a) Disconnect the I54 air conditioning amplifier assembly connector.
(b) Disconnect the g5 seat heater control sub-assembly LH connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| I54-4 (TSL) - g5-5 (THR) | Always | Below 1 Ω |
| I54-4 (TSL) or g5-5 (THR) - Body ground | Always | 10 kΩ or higher |
| I54-8 (SG-6) - g5-2 (PR) | Always | Below 1 Ω |
| I54-8 (SG-6) or g5-2 (PR) - Body ground | Always | 10 kΩ or higher |
| OK | | REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
READ NEXT:
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SEE MORE:
Inspection
INSPECTION PROCEDURE 1. INSPECT SEPARATE TYPE FRONT SEATBACK COVER LH *a Component without harness connected (Separate Type Front Seatback Cover LH (Front Seatback Heater)) (a) Check the separate type front seatback cover LH (front seatback heater). (1) Measure the resistance according to t
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