P0A01-725

L110F HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P0A01-725: Motor Electronics Coolant Temperature Sensor Circuit Range / Performance

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

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

DESCRIPTION

The hybrid vehicle control ECU detects HV coolant temperature using the coolant temperature sensor built into the inverter with converter assembly. The inverter cooling system is the same as that for MG2 and MG1, and operates independently of the engine cooling system. The hybrid vehicle control ECU uses signals from the coolant temperature sensor to check the effectiveness of the inverter cooling system. If necessary, the hybrid vehicle control ECU will control HV system output to help prevent overheating. The inverter with converter assembly detects malfunctions in the HV coolant temperature sensor and its wiring.

The inverter converts the high-voltage direct current of the HV battery into the alternating current for MG2 and MG1. The inverter generates heat during the conversion process, and this heat could damage the inverter if the cooling system is malfunctioning. Therefore, similar to MG2 and MG1, the inverter is cooled by a special cooling system consisting of an electric water pump, the cooling fan, and a radiator. This cooling system is independent of the engine cooling system. The hybrid vehicle control ECU monitors the electric water pump, cooling fan, and cooling system, and detects the following malfunction.

INSPECTION PROCEDURE

PROCEDURE

1. CHECK DTC OUTPUT (HV)
(a) Connect the intelligent tester or Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Select the following menu items:
(1) Intelligent tester - Select: DIAGNOSIS / OBD/MOBD / HV ECU / DTC INFO / CURRENT CODES.
(2) Techstream - Select: Powertrain / Hybrid Control / Trouble Codes.
(d) Check if DTCs are output.
Result:

B -- GO TO DTC CHART
A -- Continue to next step.
2. 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 ECU active test item) and the "Control the Electric Cooling Fan" active test (ENHANCED OBDII active test item) and make sure that there are no malfunctions.

C -- CHECK FOR COOLANT LEAKS AND ADD COOLANT
B -- ADD HV COOLANT
A -- Continue to next step.
3. 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.
4. PERFORM ACTIVE TEST USING INTELLIGENT TESTER OR TECHSTREAM (WATER PUMP)
(a) Connect the intelligent tester or Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Select the following menu items:
(1) Intelligent tester - Select: DIAGNOSIS / OBD/MOBD / HV ECU / ACTIVE TEST / WATER PUMP.
(2) Techstream - Select: Powertrain / Hybrid Control / Active Test / Activate the Water Pump.
(d) Perform the "Activate the Water Pump" active test for at least 1 minute.

(e) Check that there are ripples in the coolant in the inverter reserve tank.
OK:
There are ripples in the coolant in the inverter reserve tank as long as the active test is being performed.
NOTE: In addition to the active test, the water pump with motor and bracket assembly will also operate with the power switch on (READY). However, the water pump with motor and bracket assembly will not operate for 20 seconds after the power switch is turned on (READY).
HINT: The water pump with motor and bracket assembly will also operate in inspection mode.

NG -- PERFORM ACTIVE TEST USING INTELLIGENT TESTER OR TECHSTREAM (WATER PUMP)
OK -- Continue to next step.
5. PERFORM ACTIVE TEST USING INTELLIGENT TESTER OR TECHSTREAM (COOLING FAN)
(a) Select the following menu items:
(1) Intelligent tester - Select: DIAGNOSIS / ENHANCED OBDII / ACTIVE TEST / COOLING FAN
(2) Techstream - Select: Powertrain / Engine and ECT / Active Test / Control the Electric Cooling Fan.
(b) Perform the "Control the Electric Cooling Fan" active test.
OK:
The cooling fan rotates.
NG -- CHECK COOLING FAN SYSTEM
OK -- Continue to next step.
6. CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY CONNECTOR)
NOTE: 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.

(a) 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 -- Continue to next step.
7. INSPECT COOLING SYSTEM (FOR CLOGGING)
(a) Drain inverter coolant Service and Repair.
NOTE: Do not reuse the drained coolant because it may contain foreign objects.
HINT: Drain inverter coolant with the inverter reserve tank cap installed.
(b) Install the inverter reserve tank cap.
(c) Remove the drain plug.

(d) Disconnect end A of the No. 3 inverter cooling hose.
NOTE: Be careful when disconnecting the hose. Coolant may spill out of the hose.

(e) Cover the pipe shown in the illustration with packing tape.
(f) Using an air gun, apply air to the disconnected end of the hose to check for clogging in the coolant path.
NOTICE:
- Applied air pressure should be 59 kPa (0.6 kgf/cm2, 8.6 psi) or less.
- Be careful when applying air. Applying excessive air may cause coolant to overflow from the inverter reserve tank cap.

OK:
Coolant and air come out from the drain.

(g) Connect end A of the No. 3 inverter cooling hose and disconnect end B.

(h) Cover the pipe shown in the illustration with packing tape.
(i) Using an air gun, apply air to the disconnected end of the hose to check for clogging in the coolant path.
NOTICE:
- Applied air pressure should be 59 kPa (0.6 kgf/cm2, 8.6 psi) or less.
- Be careful when applying air. Applying excessive air may cause coolant to overflow from the inverter reserve tank cap.

OK:
Coolant and air come out from the drain.
(j) After this inspection, check for coolant leaks from the hose with the power switch on (READY).
NOTE: If leaks are found, replace the No. 3 inverter cooling hose and clamps.

NG -- REPLACE MALFUNCTIONING PARTS
OK -- REPLACE INVERTER WITH CONVERTER ASSEMBLY
8. PERFORM ACTIVE TEST USING INTELLIGENT TESTER OR TECHSTREAM (WATER PUMP)

(a) Connect the intelligent tester or Techstream to the DLC3.
(b) Compress the inlet hose for the water pump with motor and bracket assembly several times.
(c) Turn the power switch on (IG) again.
(d) Select the following menu items:
(1) Intelligent tester - Select: DIAGNOSIS / OBD/MOBD / HV ECU / ACTIVE TEST / WATER PUMP.
(2) Techstream - Select: Powertrain / Hybrid Control / Active Test / Activate the Water Pump.
(e) Perform the "Activate the Water Pump" active test for at least 1 minute.

(f) Check that there are ripples in the coolant in the inverter reserve tank.
OK:
There are ripples in the coolant in the inverter reserve tank as long as the active test is being performed.
NOTE: In addition to the active test, the water pump with motor and bracket assembly will also operate with the power switch on (READY). However, the water pump with motor and bracket assembly will not operate for 20 seconds after the power switch is turned on (READY).
HINT: The water pump with motor and bracket assembly will also operate in inspection mode.

NG -- CHECK FUSE (INV W/P)
OK -- ADD HV COOLANT
9. CHECK FUSE (INV W/P)

(a) Check if there is an open circuit in the fuse (INV W/P) in the engine room No. 2 relay block.
OK:
There is no open circuit in the fuse (INV W/P).
HINT: If the result is NG, replace the fuse (INV W/P) with a new one of the inspection.

NG -- CHECK CONNECTOR CONNECTION CONDITION (WATER PUMP WITH MOTOR AND BRACKET ASSEMBLY CONNECTOR)
OK -- Continue to next step.
10. CHECK CONNECTOR CONNECTION CONDITION (WATER PUMP WITH MOTOR AND BRACKET ASSEMBLY CONNECTOR)

(a) Check the connection of the water pump with motor and bracket assembly connector.
OK:
The connector is connected securely and there are no contact problems.
NG -- CONNECT SECURELY
OK -- Continue to next step.
11. CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU CONNECTOR)

(a) Check the connections of the hybrid vehicle control ECU connectors.
OK:
The connectors are connected securely and there are no contact problems.
NG -- CONNECT SECURELY
OK -- Continue to next step.
12. CHECK HARNESS AND CONNECTOR (WATER PUMP WITH MOTOR AND BRACKET ASSEMBLY)
(a) Disconnect connector A76 from the hybrid vehicle control ECU.
(b) Remove the fuse (INV W/P) from the engine room No. 2 relay block.
(c) Disconnect the water pump with motor and bracket assembly connector.
(d) Measure the resistance according to the value(s) in the table below.

Standard resistance (Check for open):

Standard resistance (Check for short):

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
13. CHECK WATER PUMP WITH MOTOR AND BRACKET ASSEMBLY

(a) Apply 12 V to terminal 2 of the INV W/P fuse holder of the engine room No. 2 relay block and check that the water pump operates.
OK:
The water pump operates.
NG -- REPLACE WATER PUMP WITH MOTOR AND BRACKET ASSEMBLY
OK -- REPLACE HYBRID VEHICLE CONTROL ECU
14. CHECK CONNECTOR CONNECTION CONDITION (WATER PUMP WITH MOTOR AND BRACKET ASSEMBLY CONNECTOR)

(a) Check the connection of the water pump with motor and bracket assembly connector.
OK:
The connector is connected securely and there are no contact problems.
NG -- CONNECT SECURELY
OK -- Continue to next step.
15. CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU CONNECTOR)

(a) Check the connections of the hybrid vehicle control ECU connectors.
OK:
The connectors are connected securely and there are no contact problems.
NG -- CONNECT SECURELY
OK -- Continue to next step.
16. CHECK HARNESS AND CONNECTOR (WATER PUMP WITH MOTOR AND BRACKET ASSEMBLY)
(a) Disconnect connector A76 from the hybrid vehicle control ECU.
(b) Remove the fuse (INV W/P) from the engine room No. 2 relay block.
(c) Disconnect the water pump with motor and bracket assembly connector.
(d) Measure the resistance according to the value(s) in the table below.

Standard resistance (Check for open):

Standard resistance (Check for short):

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
17. CHECK WATER PUMP WITH MOTOR AND BRACKET ASSEMBLY