Lexus NX: Communication Malfunction (A/C Inverter Local) (B1498)
DESCRIPTION
The hybrid vehicle control ECU and compressor with motor assembly communicate via a direct line. Compressor control is stopped and this DTC is stored if communication information is cut off or abnormal information occurs.
This DTC is also detected if high-voltage power supplied from the inverter with converter assembly to the compressor control circuit is shut off.
This DTC will be stored as a history DTC.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Memory | Note |
|---|---|---|---|---|---|
| B1498 | Communication Malfunction (A/C Inverter Local) |
|
| Memorized | - |
WIRING DIAGRAM
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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:
- Inspect the fuses for circuits related to this system before performing the following procedure.
-
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.
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- 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.
- Depending on the timing of the power supply to the 12 V power supply circuit and high-voltage circuit when the power switch is turned on (READY), an abnormal information signal may be output, causing this DTC to be stored. If the output DTC is a code that was memorized in the past, check the fuses and wire harnesses. If there is no malfunction, clear the DTC.
PROCEDURE
| 1. | CHECK CAN COMMUNICATION SYSTEM |
(a) Using the Techstream, check if the CAN communication system is functioning normally.
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| 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. | CHECK FOR DTC |
(a) Check if hybrid control system DTCs are output.
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| Result | Proceed to |
|---|---|
| DTCs are not output | A |
| Only DTC P3108-536 is output | |
| DTCs other than P3108 are output | B |
| B | | GO TO HYBRID CONTROL SYSTEM |
|
| 3. | CHECK HARNESS AND CONNECTOR (COMPRESSOR WITH MOTOR ASSEMBLY - BATTERY AND BODY GROUND) |
CAUTION:
Do not disconnect the connector on the high-voltage side.
| (a) Disconnect the compressor with motor assembly connector. NOTICE: Do not allow any foreign matter or water to enter the compressor with motor assembly. |
|
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| C43-5 (GND) - Body ground | Always | Below 1 Ω |
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Switch Condition | Specified Condition |
|---|---|---|
| C43-6 (IG1) - C43-5 (GND) | Power switch on (IG) | 11 to 14 V |
| C43-6 (IG1) - C43-5 (GND) | Power switch off | Below 1 V |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
| 4. | CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - COMPRESSOR WITH MOTOR ASSEMBLY) |
(a) Disconnect the A61 hybrid vehicle control ECU connector.
(b) Disconnect the C43 compressor with motor assembly connector.
NOTICE:
Do not allow any foreign matter or water to enter the compressor with motor assembly.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| C43-1 (CLK) - A61-10 (CLK) | Always | Below 1 Ω |
| C43-2 (DIN) - A61-9 (ITE) | Always | Below 1 Ω |
| C43-3 (DOUT) - A61-8 (ETI) | Always | Below 1 Ω |
| C43-1 (CLK) or A61-10 (CLK) - Body ground | Always | 10 kΩ or higher |
| C43-2 (DIN) or A61-9 (ITE) - Body ground | Always | 10 kΩ or higher |
| C43-3 (DOUT) or A61-8 (ETI) - Body ground | Always | 10 kΩ or higher |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
| 5. | INSPECT HIGH VOLTAGE FUSE |
CAUTION:
Be sure to wear insulated gloves.
(a) Turn the power switch off.
(b) Remove the service plug grip.
Click here
CAUTION:
Do not touch the high-voltage connectors or terminals for 10 minutes after the service plug grip is removed.
NOTICE:
After removing the service plug grip, turning the power switch on (READY) may cause a malfunction. Do not turn the power switch on (READY) with the service plug grip removed.
(c) Remove the connector cover assembly.
Click here
NOTICE:
Be sure to prevent foreign matter or water from entering the inverter with converter assembly.
| (d) Check that bolts A and B are tightened securely. |
|
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(e) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Item (Tester Connection) | Condition | Specified Condition |
|---|---|---|
| High voltage fuse (A - B) | Always | Below 1 Ω |
| NG | | REPLACE HIGH VOLTAGE FUSE |
|
| 6. | INSPECT ENGINE WIRE |
CAUTION:
Be sure to wear insulated gloves.
(a) Disconnect the C47 and C46 engine wire connectors.
Click here
NOTICE:
Do not allow any foreign matter or water to enter the compressor with motor assembly.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| C46-1 (PE) - C47-1 (ACPE) | Always | Below 1 Ω |
| C46-2 (PB) - C47-2 (ACPB) | Always | Below 1 Ω |
| C46-1 (PE) or C47-1 (ACPE) - Body ground | Always | 10 kΩ or higher |
| C46-2 (PB) or C47-2 (ACPB) - Body ground | Always | 10 kΩ or higher |
| NG | | REPLACE ENGINE WIRE |
|
| 7. | REPLACE COMPRESSOR WITH MOTOR ASSEMBLY |
(a) Replace the compressor with motor assembly.
Click here
HINT:
Since the compressor with motor assembly cannot be inspected while it is removed from the vehicle, replace the compressor with motor assembly with a new or known good one and check that the condition returns to normal.
(b) Check for DTCs.
Body Electrical > Air Conditioner > Trouble Codes| Result | Proceed to |
|---|---|
| DTC B1498 is not output | A |
| DTC B1498 is output | B |
| A | | END (COMPRESSOR WITH MOTOR ASSEMBLY IS DEFECTIVE) |
| B | | REPLACE HYBRID VEHICLE CONTROL ECU |
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