DTC    P0A01-725    Motor Electronics Coolant Temperature Sensor Circuit Range / Performance

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

for Preparation Click here


DESCRIPTION

Refer to the circuit description for DTC P0A02-719. (Click here)

DTC No.
INF Code
DTC Detection Condition
Trouble Area
P0A01
725
Sudden change in HV coolant temperature sensor output
  1. Wire harness or connector
  2. Inverter cooling system
  3. Water pump w/ motor & bracket assembly
  4. w/ converter inverter assembly
↑
726
HV coolant temperature sensor output deviation
  1. Wire harness or connector
  2. Inverter cooling system
  3. Water pump w/ motor & bracket assembly
  4. w/ converter inverter assembly

INSPECTION PROCEDURE

CAUTION:
  1. Before inspecting the high-voltage system, take safety precautions to prevent electrical shocks, such as wearing insulated gloves and removing the service plug grip. After removing the service plug grip, put it in your pocket to prevent other technicians from reconnecting it while you are working on the high-voltage system.
  2. After disconnecting the service plug grip, wait for at least 5 minutes before touching any of the high-voltage connectors or terminals.

HINT:
At least 5 minutes is required to discharge the high-voltage capacitor inside the w/ converter inverter assembly.

1.READ OUTPUT DTC (HV)

  1. Connect the intelligent tester to the DLC3.

  1. Put the vehicle into the READY-on state and wait for 10 seconds or more.

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

  1. Read output DTC. (Click here)

    Result:
    The DTC shown in the table below is output:
    DTC No.
    		Relevant Diagnosis
    P0A05-776
    		Water pump malfunction



YES
GO TO DTC CHART
NO


2.CHECK QUANTITY OF HV COOLANT

  1. Check the inverter coolant level.

    OK:
    There is a sufficient amount of coolant for the inverter.



NG
CHECK FOR COOLANT LEAKS AND ADD COOLANT
OK


3.CHECK COOLANT HOSE


    A105138E02

  1. Check if the hoses of the cooling system are not bent or clogged.

    OK:
    The hoses of the cooling system are not bent or clogged.



NG
CORRECT TO NORMAL CONDITION
OK


4.LOOSENESS AND POOR CONTACT


    A105139E01

  1. Check the connection of the water pump w/ motor & bracket assembly connector.

    OK:
    Connector is connected securely and there is no poor connection.



NG
CONNECT SECURELY
OK


5.PERFORM ACTIVE TEST BY INTELLIGENT TESTER (WATER PUMP)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to the ON position.

  1. Select the following menu items: Powertrain / Hybrid Control / Active Test / Active Water Pump.

  1. During the water pump active test, check operation of the water pump.

    OK:
    There are ripples in the reservoir tank coolant.

    HINT:
    The water pump is also activated in the READY-on state.



NG
Go to step 8
OK


6.PERFORM ACTIVE TEST BY INTELLIGENT TESTER (COOLING FAN)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to the ON position.

  1. Select the following menu items: Powertrain / Engine / Active Test / Cooling Fan.

  1. Perform the cooling fan active test.

    OK:
    The electric cooling fan rotates.



NG
CHECK COOLING FAN CIRCUIT
OK


7.CHECK CONNECTION CONDITION OF MG ECU CONNECTOR (LOOSENESS AND POOR CONTACT)

CAUTION:
Be sure to wear insulated gloves.

  1. Turn the ignition switch off and remove the service plug grip. (Click here)

    NOTICE:
    Do not put the vehicle into the READY-on state with the service plug grip removed as this may cause a malfunction.

  1. Remove the inverter cover. (Click here)

    NOTICE:
    1. Wrap the interlock round terminal for the inverter cover with vinyl tape to prevent it from shorting to ground.
    2. Be sure to prevent water in the reservoir tank from entering the inverter.
    3. Removing the inverter cover causes the MG ECU board to be exposed. Therefore, temporarily install the inverter cover for each area to be inspected.



    A103665E03

  1. Check the connections of all MG ECU connectors.

    OK:
    Connectors are connected securely and there is no poor connection.



NG
CONNECT SECURELY
OK

REPLACE W/ CONVERTER INVERTER ASSEMBLY 

8.CHECK HARNESS AND CONNECTOR (HV CONTROL ECU - WATER PUMP)


    A105205E03

  1. Turn the ignition switch off.

  1. Disconnect the H29 connector from the HV control ECU.

  1. Disconnect the W5 water pump connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance (Check for open):
    Tester Connection
    		Specified Condition
    NIWP (H29-29) - NWP (W5-1)
    		Below 1 Ω
    IWP (H29-23) - SWP (W5-2)
    		Below 1 Ω
    GND (W5-3) - Body ground
    		Below 1 Ω
    Engine room R/B No.4 INV W/P fuse terminal 2 - +BWP (W5-4)
    		Below 1 Ω

    Standard Resistance (Check for short):
    Tester Connection
    		Specified Condition
    NIWP (H29-29) or NWP (W5-1) - Body ground
    		10 kΩ or more
    IWP (H29-23) or SWP (W5-2) - Body ground
    		10 kΩ or more
    Engine room R/B No.4 INV W/P fuse terminal 2 or - +BWP (W5-4) - Body ground
    		10 kΩ or more



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE WATER PUMP W/ MOTOR & BRACKET ASSEMBLY