P0A01
HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM: P0A01-726, P0A04-725: Motor Electronics Coolant Temperature Sensor Circuit Range / Performance
P0A04-725 - Motor Electronics Coolant Temperature Sensor Circuit Intermittent
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.
INSPECTION PROCEDURE
CAUTION:
- 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 Hybrid Control System: Precaution.
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 Service Precautions.
PROCEDURE
1. CHECK DTC OUTPUT (HYBRID CONTROL)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
(d) Check if DTCs are output.
Result:
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) Hybrid Control System
A -- Continue to next step.
2. CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY CONNECTOR) P0343
NG -- CONNECT SECURELY
OK -- Continue to next step.
3. CHECK QUANTITY OF HV COOLANT
(a) Check the coolant level in the inverter reserve tank.
(b) Check for coolant leaks.
Result
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.
C -- INSPECT FOR COOLANT LEAK AND ADD COOLANT
B -- ADD HV COOLANT
A -- Continue to next step.
4. CHECK COOLANT HOSE
(a) Check if the hoses of the cooling system are kinked or clogged.
NG -- CORRECT THE PROBLEM
OK -- Continue to next step.
5. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE ELECTRIC COOLING FAN)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Electric Cooling Fan.
(d) Perform the "Control the Electric Cooling Fan" Active Test.
OK:
The cooling fan rotates.
(e) Turn the power switch off.
NG -- CHECK COOLING FAN SYSTEM Cooling Fan Circuit
OK -- Continue to next step.
6. CHECK HV COOLANT (CHECK FOR CONDITIONS THAT MAY HAVE CAUSED FREEZING)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Read the freeze frame data Ambient Temperature using the Techstream.
(d) Check if the freeze frame data Ambient Temperature is below freezing.
Result:
HINT
- HV coolant (SLLC) with a 30% concentration freezes at 5°F (-15 °C) and HV coolant (SLLC) with a 50% concentration freezes at -31°F (-35°C).
- If the HV coolant freezes in the HV radiator or HV water pump, the coolant temperature in the inverter with converter assembly rises because the HV coolant cannot circulate. As a result, a DTC may be set.
- A DTC is set when the water pump impeller cannot rotate due to freezing of the HV coolant.
- 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.
(e) Turn the power switch off.
B -- REPLACE INVERTER WITH CONVERTER ASSEMBLY Components
A -- Continue to next step.
7. REPLACE HV COOLANT
(a) Replace the HV coolant with coolant having an appropriate concentration (appropriate freeze point) for the vehicle usage conditions Service and Repair.
NEXT -- Continue to next step.
8. CHECK INVERTER WATER PUMP ASSEMBLY
(a) Perform a road test and check that DTCs are not stored.
OK:
DTCs are not stored.
NG -- REPLACE INVERTER WATER PUMP ASSEMBLY Components
OK -- COMPLETED