Inspection Procedure

WARNING:

Before inspecting the high-voltage system or disconnecting the low voltage connector of the inverter with converter assembly, take safety precautions such as wearing insulated gloves and removing the service plug grip to prevent electrical shocks. After removing the service plug grip, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.
After removing the service plug grip, wait for at least 10 minutes before touching any of the high-voltage connectors or terminals. After waiting for 10 minutes, check the voltage at the terminals in the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work. Refer to PRECAUTION [12/2014 - ] .
HINT:

Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

NOTE:

After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work. Refer to PRECAUTION [12/2014 - 05/2015] .

HINT:

If there is a malfunction in the DC/DC converter internal circuit, P0A08-264 is stored within 2 minutes of the power switch being turned on (READY) regardless of the auxiliary battery voltage.
If the auxiliary battery voltage is low, the power switch will turn off regardless of DTCs being stored or not.
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 lever in P, the ignition switch to ON (READY) and the following conditions met, then confirm that Data List item "+B" 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 gradually drops.)
  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.
- If the DC/DC converter has an internal malfunction, DTC P0A08-264 is stored regardless of the auxiliary battery voltage after performing this procedure.
- If the auxiliary battery voltage drops, the ignition switch turns off regardless of DTCs being stored or not.
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 it is until the electric current flowing into the auxiliary battery becomes 10 A or less.
  2. Turn the ignition switch to ON (READY) and the headlight switch and A/C blower fan switch in the HI position, and the window defogger turned on.
  3. Confirm that the current drawn from the auxiliary battery is 0 A or lower and the auxiliary battery voltage is between 13.0 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.

MALFUNCTION CASES TO STORE DTC P0A08-264

Malfunction Case	Remarks	Inspection Step
Fuse is blown. (DC/DC)	-	4
High-voltage insulation between the inverter, generator (MG1), motor (MG2) and body ground is poor (body ground).	DTC P0AA6 may be stored if the ground potential fluctuates due to a high-voltage insulation malfunction.	1
A signal connector of the hybrid vehicle control ECU or inverter is not connected securely.	-	2, 3
The DC/DC converter is malfunctioning.	Inspect the DC/DC converter function.	9
Control is suspended due to overheating. (The inverter water pump assembly is malfunctioning, the coolant is not sufficient, a hose is clogged, etc.)	When the inverter is overheating, the DC/DC converter has self protection control that suspends the DC/DC converter control. As that time, 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.	10 to 13, 17

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.
In addition, if this vehicle is jump started by a vehicle with a 24 V auxiliary battery or the auxiliary battery cables are connected to the opposite auxiliary battery terminals, 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 power switch off.)
Confirm that high electrical load equipment such as a high-capacitance audio device or electric kettle is used on 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 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 on (READY), the auxiliary battery voltage may be low. Charge the auxiliary battery.