P0A05
P310 HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P0A05-776: Motor Electronics Coolant Pump Control Circuit / Open
DTC P0A05-776 - Motor Electronics Coolant Pump Control Circuit / Open
DESCRIPTION
The hybrid vehicle control ECU detects HV coolant temperature using the coolant temperature sensor built into the inverter. The inverter cooling system is the same as that for the MG2 and MG1, and operates independently of the engine cooling system. The hybrid vehicle control ECU controls the inverter cooling system to prevent overheating based on signals from the coolant temperature sensor. The ECU also monitors cooling system operation and detects malfunctions in the HV coolant temperature sensor and the circuit.
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
1. PERFORM ACTIVE TEST USING TECHSTREAM (WATER PUMP)
(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) Clear DTCs and freeze frame data.
(e) Select the following menu items: Powertrain / Hybrid Control / Active Test / Activate the Water Pump.
(f) During the "Activate the Water Pump" active test, check operation of the water pump.
OK:
There are ripples in the inverter reserve tank coolant.
HINT: The water pump is also activated in the power switch on (READY) state.
NG -- CHECK HARNESS AND CONNECTOR (WATER PUMP)
OK -- Continue to next step.
2. INSPECT HYBRID VEHICLE CONTROL ECU
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Select the following menu items: Powertrain / Hybrid Control / Active Test / Activate the Water Pump.
(d) Connect an oscilloscope between the hybrid vehicle control ECU terminals specified in the table below and measure the waveform while performing the active test.
OK:
The waveform appears as shown in the illustration.
NG -- CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - WATER PUMP)
OK -- Continue to next step.
3. READ OUTPUT DTC (HV)
(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:
B -- REPLACE HYBRID VEHICLE CONTROL ECU
A -- Continue to next step.
4. PERFORM REPRODUCTION TEST
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Select the following menu items: Powertrain / Hybrid Control / Active Test / Activate the Water Pump.
(d) During the "Activate the Water Pump" active test, check for pulse signals according to the table below.
(e) Perform the following reproduction tests to check for intermittent problems.
OK:
The interval of pulse signal output is normal.
NG -- REPAIR OR REPLACE MALFUNCTIONING PARTS
OK -- REPLACE WATER PUMP WITH MOTOR AND BRACKET ASSEMBLY
5. CHECK HARNESS AND CONNECTOR (WATER PUMP)
(a) Turn the power switch off.
(b) Disconnect the A52 water pump with motor and bracket assembly connector.
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:
NG -- CHECK FUSE (INV-W/P)
OK -- Continue to next step.
6. CHECK COOLANT HOSE
(a) Check if the hoses of the cooling system are not kinked or clogged.
OK:
The hoses of the cooling system are not kinked or clogged.
NG -- CORRECT THE PROBLEM
OK -- Continue to next step.
7. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - WATER PUMP)
(a) Turn the power switch off.
(b) Disconnect the D35 connector from the hybrid vehicle control ECU.
(c) Disconnect the A52 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.
8. INSPECT HYBRID VEHICLE CONTROL ECU
(a) Connect the hybrid vehicle control ECU connector and water pump with motor and bracket assembly connector.
(b) Turn the power switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:
NG -- INSPECT WATER PUMP WITH MOTOR AND BRACKET ASSEMBLY (IWP TERMINAL VOLTAGE)
OK -- Continue to next step.
9. INSPECT HYBRID VEHICLE CONTROL ECU
(a) Turn the power switch on (READY).
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:
NG -- REPLACE HYBRID VEHICLE CONTROL ECU
OK -- REPLACE WATER PUMP WITH MOTOR AND BRACKET ASSEMBLY
10. INSPECT WATER PUMP WITH MOTOR AND BRACKET ASSEMBLY (IWP TERMINAL VOLTAGE)
(a) Disconnect the D35 connector from the hybrid vehicle control ECU.
(b) Turn the power switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:
NG -- REPLACE WATER PUMP WITH MOTOR AND BRACKET ASSEMBLY
OK -- REPLACE HYBRID VEHICLE CONTROL ECU
11. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - WATER PUMP)
(a) Turn the power switch off.
(b) Disconnect the D35 connector from the hybrid vehicle control ECU.
(c) Disconnect the A52 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.
12. INSPECT WATER PUMP WITH MOTOR AND BRACKET ASSEMBLY
(a) Disconnect the A52 water pump with motor and bracket assembly connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
NG -- REPLACE WATER PUMP WITH MOTOR AND BRACKET ASSEMBLY
OK -- REPLACE HYBRID VEHICLE CONTROL ECU
13. CHECK FUSE (INV-W/P) P0A01-725
NG -- REPLACE FUSE (INV-W/P)
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR