Air Conditioning System

HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: P0AA6-611: Hybrid Battery Voltage System Isolation Fault
P0AA6-611 - Hybrid Battery Voltage System Isolation Fault

DESCRIPTION

The DTC is stored if there is insulation trouble with the high-voltage circuit in the air conditioning system. Possible causes are poor insulation in the compressor with motor assembly, or mixing of any oil other than ND-OIL 11 in the refrigerant cycle.

A high-voltage motor is built into the electrical compressor and is cooled directly with refrigerant. Compressor oil (ND-OIL 11) with high insulation performance is used because a leakage of electrical power may occur if regular compressor oil (ND-OIL 8) is used.

CAUTION:
- Wear insulated gloves and pull out the service plug grip before inspection as procedures may require disconnecting high-voltage connectors.
- Be sure to carry the removed service plug grip because other workers may install it by mistake.
- Do not touch the high-voltage connectors or terminals for 10 minutes after the service plug grip is removed.






WIRING DIAGRAM





INSPECTION PROCEDURE

CAUTION:
- Wear insulated gloves and pull out the service plug grip before inspection as procedures may require disconnecting high-voltage connectors.
- Be sure to carry the removed service plug grip because other workers may install it by mistake.
- Do not touch the high-voltage connectors or terminals for 10 minutes after the service plug grip is removed.
NOTICE:
- After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work Service Precautions.
- Electrical insulation performance may decrease significantly if even a small amount of oil other than ND-OIL 11 is used (or enters) in the refrigerant cycle, causing the DTC to be output.
- If other oil is accidentally used and a DTC is output, collect the oil in the refrigerant cycle into the compressor and replace it with ND-OIL 11 to increase the ND-OIL 11 ratio amount.
- Replace the main components (evaporator, condenser, and compressor) if a large amount of oil other than ND-OIL 11 enters the system. Failing to do so may cause electrical insulation performance to remain low, causing the DTC to be output.
- The hybrid control system and air conditioning system output DTCs separately. Inspect DTCs following the flow chart for the hybrid control system first if any DTCs from those systems are output simultaneously.
- Inspect the fuses for circuits related to this system before performing the following inspection procedure.

HINT
If it can be confirmed that any compressor oil other than ND-OIL 11 has been used in the vehicle, replace the air conditioning cycle.

PROCEDURE

1. CHECK CAN COMMUNICATION SYSTEM

(a) Using the Techstream to check if the CAN communication system is functioning normally.

Result:





B -- GO TO CAN COMMUNICATION SYSTEM How to Proceed With Troubleshooting
A -- Continue to next step.

2. INSPECT COMPRESSOR WITH MOTOR ASSEMBLY

CAUTION:
Because the compressor has a high-voltage circuit, wear insulated gloves and pull out the service plug grip to cut off the high-voltage circuit before inspection.

(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(b) Turn the power switch on (READY).

(c) Prepare the vehicle according to the table below for 3 minutes.





(d) Turn the power switch off.

(e) Remove the service plug grip.

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.

(f) Disconnect the connector from the compressor with motor assembly.





(g) Using a megohmmeter, measure the resistance according to the value(s) in the table below.

Standard Resistance:





Text in Illustration





NG -- REPLACE COMPRESSOR WITH MOTOR ASSEMBLY Removal
OK -- Continue to next step.

3. INSPECT AIR CONDITIONING CYCLE

CAUTION:
Because the compressor has a high-voltage circuit, wear insulated gloves and pull out the service plug grip to cut off the high-voltage circuit before inspection.

(a) Reconnect the connector to the compressor with motor assembly.

(b) Install the service plug grip.

(c) Turn the power switch on (IG).

(d) Set the A/C temperature to 25°C (77°F) and the blower switch to LO and then operate the compressor for 10 minutes to circulate the refrigerant and collect as much compressor oil as possible in the compressor.

(e) Turn the power switch off.

(f) Using a spot cooler or other tools, cool down the compressor with motor assembly for 30 minutes, or leave the vehicle overnight before inspection.

NOTICE:
Do not operate the compressor before inspection.

(g) Remove the service plug grip.

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.

(h) Disconnect the connector from the compressor with motor assembly.





(i) Using a megohmmeter, measure the resistance according to the value(s) in the table below.

Standard Resistance:





NOTICE:
If the results are out of the specified range, replace the compressor without operating it.

Text in Illustration





NG -- REPLACE AIR CONDITIONING CYCLE Service and Repair

OK -- REPLACE COMPRESSOR WITH MOTOR ASSEMBLY Removal