DTC P0AA6-49: Hybrid/EV Battery Voltage System Isolation Internal Electronic Failure; DTC P1C7C-49: Hybrid/EV Battery Voltage System Isolation (A/C Area) Internal Electronic Failure; DTC P1C7D-49: Hybrid/EV Battery Voltage System Isolation (Hybrid/EV Battery Area) Internal Electronic Failure; DTC P1C7E-49: Hybrid/EV Battery Voltage System Isolation (Transaxle Area) Internal Electronic Failure; DTC P1C7F-49: Hybrid/EV Battery Voltage System Isolation (Direct Current Area) Internal Electronic Failure [12/2019 - 11/2023]: Description

The hybrid vehicle control ECU monitors the battery voltage sensor and detects insulation malfunctions in the high-voltage system.

HINT: 

• *1: The insulation malfunction detection circuit in the battery voltage sensor monitors the insulation resistance between the high voltage circuits and body. If the insulation resistance decreases, the hybrid vehicle control ECU stores DTC P0AA6-49 and illuminates the master warning first regardless of malfunction area.

  Depending on the vehicle condition, the high voltage circuit insulation resistance may return to normal. So if DTC P0AA6-49 is output, complete the following steps as soon as possible.

• *2: If the following operations are performed within the same trip after DTC P0AA6-49 is stored, just one of the related DTCs (P1C7C-49, P1C7D-49, P1C7E-49 or P1C7F-49) will be stored.
• *3: w/ 1500W Voltage inverter assembly
  1. Apply the parking brake firmly.
     NOTE:

     Perform this test with the AUTO function (shift-linked function) of the electric parking brake system off.

     HINT: 

     When the parking brake indicator (red) is illuminated after the electric parking brake switch assembly has been pulled to the lock side, the maximum amount of braking force is applied if the electric parking brake switch assembly is pulled to the lock side one more time.

  2. Wait for 1 minute or more with the vehicle stopped, the brake pedal firmly depressed, the ignition switch ON (READY), shift lever in D and the air conditioning system on (Lo/MAX COOL, blower speed HI).
  3. Turn the ignition switch off and wait for 2 minutes or more.

     HINT: 

     • DTCs and freeze frame data are useful information in determining the malfunctioning part. Before performing diagnosis, make sure to check and make a note of all output DTCs and freeze frame data. (Even if a high-voltage insulation malfunction cannot be reproduced, once stored, insulation malfunction DTCs will not be cleared unless the clear operation is performed.)
     • When the insulation resistance of the HV battery area decreases and the ignition switch is turned to ON, DTC P1C7D-49 is stored within 2 minutes.
• When measuring insulation resistance using a megohmmeter, measure the resistance while jiggling the high voltage wire harness.

Use the following items as a reference when duplicating the vehicle conditions at the time when the malfunction occurred.

Data List 

• Vehicle Speed
• Engine Run Time
• Auxiliary Battery Voltage
• Distance from DTC Cleared
• Ready Signal
• Hybrid Battery SOC