DTC    P0A01-726    Motor Electronics Coolant Temperature Sensor Circuit Range / Performance

DTC    P0A04-725    Motor Electronics Coolant Temperature Sensor Circuit Intermittent

for Preparation Click here


DESCRIPTION

The power management control ECU (HV CPU) detects HV coolant temperature using the coolant temperature sensor built into the inverter with converter assembly. The power management control ECU (HV CPU) uses signals from the coolant temperature sensor to check the effectiveness of the inverter cooling system. If necessary, the power management control ECU (HV CPU) will limit inverter output to help prevent inverter overheating. The power management control ECU (HV CPU) also detects malfunctions in the sensor based on the HV coolant temperature sensor values. The inverter with converter assembly detects malfunctions in the HV coolant temperature sensor and its wiring.

DTC No.
INF Code
DTC Detection Condition
Trouble Area
P0A01
726
Temperature calculated by power management control ECU and actual temperature are different for 10 seconds or more.
  1. Inverter cooling system
  2. Cooling fan system
  3. Inverter with converter assembly
  4. Inverter water pump assembly
P0A04
725
Unusual sudden change in HV coolant temperature sensor output occurs and the offset continues, or unusual sudden change in HV coolant temperature sensor output occurs repeatedly.

INSPECTION PROCEDURE

CAUTION:
  1. 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.
  2. 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 (Click here).

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

NOTICE:
After turning the power 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 (Click here).

1.CHECK DTC OUTPUT (HYBRID CONTROL)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Select the following menu items: Powertrain / Hybrid Control / DTC.

  1. Check if DTCs are output.

    Result:
    Result
    		Proceed to
    P0A01-726 or P0A04-725 is output.
    		A
    Any of the following DTCs are also output.
    		B


    DTC No.
    		Relevant Diagnosis
    P0A93-346
    		Inverter Cooling System Performance
    P0C73-776
    		Motor Electronics Coolant Pump "A" Control Performance
    P314A-828
    		Inverter Coolant Pump Speed Signal

    HINT:
    P0A01-726 or P0A04-725 may be set due to a malfunction which also causes DTCs in the preceding table to be set. In this case, first troubleshoot the output DTCs in the preceding table. Then, perform a test to attempt to reproduce the problems, and check that no DTCs are output.



B
GO TO DTC CHART (HYBRID CONTROL SYSTEM) (Click here)
A


2.CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY CONNECTOR)
A214648

CAUTION:
Be sure to wear insulated gloves.

  1. Check that the service plug grip is not installed.

    NOTICE:
    After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

NOTICE:
Before disconnecting the connector, confirm that it is properly connected by checking that the locking claws are engaged and that the connector does not pull out.

  1. Check the connection of the low voltage connector of the inverter with converter assembly.

    OK:
    The connector is connected securely and there are no contact problems.

    HINT:
    When connecting the connector, insert it with the locking lever in the raised position. Rotate the lever downward and make sure that the connector is pulled into its socket. When the locking lever is in its fully closed position, a click will be heard as its locking claws engage. After the click is heard, pull up on the connector to confirm that it is properly connected.



NG
CONNECT SECURELY
OK


3.CHECK QUANTITY OF HV COOLANT

  1. Check the coolant level in the inverter reserve tank.

  1. Check for coolant leaks.
    Result 
    Result
    		Proceed to
    Coolant leaks are not evident. A sufficient amount of coolant remains in the inverter reserve tank.
    		A
    Coolant leaks are not evident. No coolant remains in the inverter reserve tank.
    		B
    Coolant leaks are evident.
    		C

    HINT:
    After repairing the coolant leaks and adding coolant, perform the "Activate the Water Pump" Active Test (HV Active Test item) and the "Control the Electric Cooling Fan" Active Test (Engine Active Test item) and make sure that there are no malfunctions.



B
ADD HV COOLANT

C
INSPECT FOR COOLANT LEAK AND ADD COOLANT
A


4.CHECK COOLANT HOSE

  1. Check if the hoses of the cooling system are kinked or clogged.



NG
CORRECT THE PROBLEM
OK


5.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE ELECTRIC COOLING FAN)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Electric Cooling Fan.

  1. Perform the "Control the Electric Cooling Fan" Active Test.

    OK:
    The cooling fan rotates.

  1. Turn the power switch off.



NG
CHECK COOLING FAN SYSTEM (Click here)
OK


6.CHECK HV COOLANT (CHECK FOR CONDITIONS THAT MAY HAVE CAUSED FREEZING)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Read the freeze frame data Ambient Temperature using the intelligent tester.

  1. Check if the freeze frame data Ambient Temperature is below freezing.

    Result:
    Result
    		Proceed to
    Ambient Temperature value is below freezing temperature of the HV coolant
    		A
    Ambient Temperature value is above freezing temperature of the HV coolant
    		B

    HINT:
    1. HV coolant (SLLC) with a 30% concentration freezes at -15°C (5°F) and HV coolant (SLLC) with a 50% concentration freezes at -35°C (-31°F).
    2. If the HV coolant freezes in the HV radiator or inverter water pump assembly, the coolant temperature in the inverter with converter assembly rises because the HV coolant cannot circulate. As a result, a DTC may be set.
    3. A DTC is set when the inverter water pump impeller cannot rotate due to freezing of the HV coolant.
    4. If a DTC is set due to freezing of HV coolant, the problem cannot be reproduced. Judge whether freezing of HV coolant occurred according to the freeze point of the HV coolant, HV coolant change history and ambient temperature when the DTC was set.

  1. Turn the power switch off.



B
REPLACE INVERTER WITH CONVERTER ASSEMBLY (Click here)
A


7.REPLACE HV COOLANT

  1. Replace the HV coolant with coolant having an appropriate concentration (appropriate freeze point) for the vehicle usage conditions (Click here).


NEXT


8.CHECK INVERTER WATER PUMP ASSEMBLY

  1. Perform a road test and check that DTCs are not stored.

    OK:
    DTCs are not stored.



NG
REPLACE INVERTER WATER PUMP ASSEMBLY (Click here)
OK

COMPLETED