Air Conditioning System

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

DTC P0AA6-611 - Hybrid Battery Voltage System Isolation Fault

DESCRIPTION

The DTC is output if there is insulation trouble with the high-voltage circuits 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.
The motor driven with high-voltage 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.
NOTICE:
- 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.
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.
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 DTC (CAN COMMUNICATION SYSTEM)
(a) Use the Techstream to check if the CAN communication system is functioning normally.

Result





B -- GO TO CAN COMMUNICATION SYSTEM
A -- Continue to next step.
2. INSPECT COMPRESSOR WITH MOTOR ASSEMBLY
(a) Clear the DTCs DTC Check / Clear.
(b) Turn the power switch ON (IG).
(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:
- 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.
- Do not touch the high-voltage connectors or terminals for 10 minutes after the service plug grip is removed.
NOTICE:
Do not start the engine with the service plug grip removed because it may cause a malfunction.




(f) Disconnect the k1 compressor with motor assembly connector.
(g) Using a megohmmeter, measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPLACE COMPRESSOR WITH MOTOR ASSEMBLY
OK -- Continue to next step.
3. INSPECT AIR CONDITIONING CYCLE
(a) Reconnect the k1 compressor with motor assembly connector.
(b) Install the service plug grip.
(c) Turn the power switch ON (IG).
(d) Set the A/C setting temperature to 25°C (77°F) and the blower switch LO and then operate the compressor for 10 minutes to circulate the refrigerant cycle with refrigerant and collect as much compressor oil as possible.
(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.
NOTICE:
Do not start the engine with the service plug grip removed because it may cause a malfunction.




(h) Disconnect the k1 compressor with motor assembly connector.
(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.

NG -- REPLACE AIR CONDITIONING CYCLE
OK -- REPLACE COMPRESSOR WITH MOTOR ASSEMBLY