Lexus NX: Rear Left Seat Heat Sensor Circuit (B14C3)
DESCRIPTION
Power supply to the temperature sensor built into the rear seat cushion heater stops if one of the following occurs: 1) an open or short occurs in the temperature sensor circuit; or 2) the temperature sensor is damaged and its output value does not change.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area |
|---|---|---|---|
| B14C3 | Rear 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.
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.
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for Manual Tilt and Manual Telescopic Steering Column:
-
for Power Tilt and Power Telescopic Steering Column:
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for Manual Tilt and Manual Telescopic Steering Column:
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When the auxiliary battery is disconnected or the air conditioning amplifier assembly is replaced, be sure to perform servo motor initialization.
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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 B14C3 is not output.
| OK | .gif) | USE SIMULATION METHOD TO CHECK |
|
| 3. | READ VALUE USING TECHSTREAM (RL 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 |
|---|---|---|---|---|
| RL Seat Heater Temperature | Rear seat LH heater temperature | -29.7°C to 59.55°C |
| Refreshing seat switch (for Rear seat LH) is on (w/ Rear Seat Heater) |
| Tester Display |
|---|
| RL 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 BENCH TYPE REAR SEAT CUSHION COVER |
(a) Remove the bench type rear seat cushion cover.
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for Manual Seat:
-
for Power Seat:
(b) Inspect the bench type rear seat cushion cover.
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for Manual Seat:
-
for Power Seat:
| NG | | REPLACE BENCH TYPE REAR SEAT CUSHION COVER |
|
| 5. | CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - BENCH TYPE REAR SEAT CUSHION COVER) |
(a) Disconnect the I54 air conditioning amplifier assembly connector.
(b) Disconnect the h6 bench type rear seat cushion cover connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| I54-20 (TFAL) - i6-3 | Always | Below 1 Ω |
| I54-20 (TFAL) or i6-3 - Body ground | Always | 10 kΩ or higher |
| I54-23 (SG-7) - i6-2 | Always | Below 1 Ω |
| I54-23 (SG-7) or i6-2 - Body ground | Always | 10 kΩ or higher |
| OK | | REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
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Precaution
PRECAUTION PRECAUTION FOR DISCONNECTING CABLE FROM NEGATIVE AUXILIARY BATTERY TERMINAL NOTICE:
After the power switch is turned off, there may be a waiting time before disconnecting the negative (-) auxiliary battery terminal.
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When disconnecting and reconnecting the auxiliary batte
