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. |
|
(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 |
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