Lexus NX: A/C Inverter Cooling / Heating System Malfunction (B1475)
DESCRIPTION
The temperature sensor of the compressor with motor assembly detects the A/C inverter temperature.
If the temperature exceeds the maximum, operation of the compressor with motor assembly will be stopped, and this DTC will be stored.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Memory | Note |
|---|---|---|---|---|---|
| B1475 | A/C Inverter Cooling / Heating System Malfunction | Temperature of the A/C inverter is outside the specified range (temperature is too high), or there is an open or short to ground in the temperature sensor circuit |
| Memorized | - |
CAUTION / NOTICE / HINT
CAUTION:
- Wear insulated gloves and pull out the service plug grip before inspection as procedures may require disconnecting high-voltage connectors. Carry the removed service plug in your pocket to prevent other technicians from accidentally reconnecting it while you are servicing the vehicle.
- Do not touch the high-voltage connectors or terminals for 10 minutes after the service plug grip is removed.
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 battery terminal
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HINT:
When disconnecting and reconnecting the auxiliary battery, there is an automatic learning function that completes learning when the respective system is used.
Click here
- The hybrid control system and air conditioning system output DTCs separately. Perform troubleshooting for the hybrid control system first if DTCs from these systems are output simultaneously.
PROCEDURE
| 1. | CHECK CAN COMMUNICATION SYSTEM |
(a) Using the Techstream, check if the CAN communication system is functioning normally.
Click here
| Result | Proceed to |
|---|---|
| CAN communication system DTCs are not output | A |
| CAN communication system DTCs are output | B |
| B | .gif) | GO TO CAN COMMUNICATION SYSTEM |
|
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| 2. | PERFORM ACTIVE TEST USING TECHSTREAM |
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine and ECT / Active Test.
(e) Check the operation by referring to the table below.
Powertrain > Engine and ECT > Active Test| Tester Display | Measurement Item | Control Range | Diagnostic Note |
|---|---|---|---|
| Control the Electric Cooling Fan | Control electric cooling fan motor | ON/OFF | Perform this test when the following conditions are met:
|
| Tester Display |
|---|
| Control the Electric Cooling Fan |
OK:
Electric cooling fan operates smoothly.
| NG | | GO TO COOLING FAN SYSTEM |
|
| 3. | CHECK REFRIGERANT PRESSURE |
(a) Install a manifold gauge set.
Click here
(b) Turn the power switch on (READY).
| (c) Read the manifold gauge pressure when the following conditions are met. (1) Prepare the vehicle according to the table below.
|
|
Standard Pressure:
Low pressure side
150 to 250 kPa (1.5 to 2.5 kgf/cm2, 22 to 36 psi)
High pressure side
1370 to 1570 kPa (14 to 16 kgf/cm2, 199 to 228 psi)
| NG | | CHARGE REFRIGERANT |
|
| 4. | CHECK FOR DTC |
(a) Clear the DTCs.
Click here
(b) Turn the power switch on (READY).
(c) Prepare the vehicle according to the table below.
| Item | Condition |
|---|---|
| Blower speed | HI |
| A/C switch | On |
| Temperature setting | MAX. COLD |
(d) Check for DTCs.
Click here
| Result | Proceed to |
|---|---|
| DTC B1475 is not output | A |
| DTC B1475 is output | B |
NOTICE:
If the engine keeps idling when ambient temperature is high, the compressor with motor assembly may automatically stop to protect the inverter circuit, and DTC B1475 may be stored.
| A | | USE SIMULATION METHOD TO CHECK |
| B | | REPLACE COMPRESSOR WITH MOTOR ASSEMBLY |
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