Caution / Notice / Hint

WARNING: This page is about a different car, the 2025 Toyota Highlander and 2024 Toyota Highlander. However, it is still accessible from the selected car via links, so may be relevant.

WARNING:

Refer to the precautions before inspecting high voltage circuit.

Refer to PRECAUTION [11/2023 - ]

NOTE:

After the ignition switch is turned off, there may be a waiting time before disconnecting the auxiliary negative (-) battery terminal.
Refer to BEFORE DISCONNECTING BATTERY [11/2023 - ]
When disconnecting and reconnecting the auxiliary battery
HINT:

When disconnecting and reconnecting the auxiliary battery, there is an automatic learning function that completes learning when the respective system is used.

Refer to AUTOMATIC LEARNING CHART [11/2023 - ]

HINT:

After repair, clear the DTCs, turn the ignition switch off and wait for 30 seconds or more and perform the following procedure to confirm that the auxiliary battery low voltage indicated by this DTC has been repaired.
1. Wait for 2 minutes with the shift state in park (P), the ignition switch ON (READY) and the following conditions met, then confirm that Data List item "BATT Voltage (Hybrid control system)" is between 13.0 and 15.0 V.
  (If charging is not performed and the electrical load increases, +B voltage may not be steady and will gradually drop.)
  1. Headlight switch is in the HI position.
  2. A/C blower fan switch is in the HI position.
  3. Window defogger switch is turned on.
By performing the following procedure, the DC/DC converter function can be checked.
1. Connect the AC/DC 400 A probe to the positive (+) auxiliary battery cable.
  1. Turn the ignition switch to ON (READY) and leave the vehicle as is until the electric current flowing to the auxiliary battery becomes 10 A or less.
  2. Turn the ignition switch to ON (READY) and turn the headlight switch and A/C blower fan switch to the HI position and the window defogger on.
  3. Confirm that the current drawn from the auxiliary battery is 0 A or lower and the auxiliary battery voltage is between 12.5 and 15.0 V.

This DTC may be also stored when a part other than the DC/DC converter is malfunctioning or depending on user operation.

If this vehicle is used to jump start another vehicle with a discharged battery, a fuse may blow due to overcurrent or the DC/DC converter self-protection may be activated. Also, if this vehicle is jump started by a vehicle with a 24 V battery, the same malfunction may occur and this DTC may be stored. (The suspended DC/DC converter control will return to normal by clearing the DTCs and turning the ignition switch off.)

Check whether high electrical load equipment such as a high-capacitance audio device or electric kettle is used in the vehicle. (A fuse of the auxiliary battery may be blown due to overcurrent.)

If the DC/DC converter is malfunctioning, the auxiliary battery cannot be charged. Therefore, once the ignition switch is turned off, it may be impossible to turn it to ON (READY) again if the auxiliary battery is completely discharged. In this case, charge the auxiliary battery. Be careful as charging is not performed during the inspection.

If the ignition switch turns off immediately after it is turned to ON (READY), the auxiliary battery voltage may be low. Charge the auxiliary battery.