Lexus NX: A/C Inverter Load System Malfunction (B1476)
DESCRIPTION
The operation of the compressor with motor assembly is stopped and this DTC is stored if the rotation load is too large or too small while the compressor with motor assembly is operating.
Possible causes are refrigerant leaks, overcharged refrigerant, insufficient cooling due to a condenser fan circuit malfunction, or compressor lock.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Memory | Note |
|---|---|---|---|---|---|
| B1476 | A/C Inverter Load System Malfunction | Motor rotation load while the compressor is operating is too large or too small |
| 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.
Click here
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When disconnecting and reconnecting the auxiliary battery terminal
Click here
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 |
| NG | | GO TO COOLING FAN SYSTEM |
|
| 3. | CHECK REFRIGERANT PRESSURE |
(a) Install a manifold gauge set.
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(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.
|
|
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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)
| OK | | REPLACE COMPRESSOR WITH MOTOR ASSEMBLY |
| NG | | CHARGE REFRIGERANT |
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