DTC P0C73-776: Motor Electronics Coolant Pump "A" Control Performance: Procedure

B → ADD EV COOLANT 

C → REPAIR COOLANT LEAKS AND ADD COOLANT 

A: Go to next step 

NG → CORRECT THE PROBLEM 

OK: Go to next step 

HINT: 

When the auxiliary battery voltage is low, the water pump with motor assembly may not operate.

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Enter the following menus: Powertrain / EV / Data List.
4. Select Inverter Water Pump Revolution in the Data List.
5. Read the Data List.

   Standard

   Techstream Display	Switch Condition	Specified Condition
   Inverter Water Pump Revolution	Power switch on (IG)	625 rpm or less

6. Turn the power switch off.

NG → See step   6 

OK: Go to next step 

HINT: 

When the auxiliary battery voltage is low, the water pump with motor assembly may not operate.

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Enter the following menus: Powertrain / EV / Active Test / Activate the Water Pump.
4. Select Inverter Water Pump Revolution in the Data List.
5. While performing the "Activate the Water Pump" Active Test, check Inverter Water Pump Revolution in the Data List.

   Standard

   Techstream Display	Switch Condition	Specified Condition
   Inverter Water Pump Revolution	Power switch on (IG)	2000 to 5375 rpm

   HINT: 

   Perform the Active Test with the inverter coolant temperature between -15 and 65°C (5 to 149°F).

6. Turn the power switch off.

NG → See step   6 

OK: Go to next step 

B → See step   13 

A → See step   14 

NG → CONNECT SECURELY 

OK: Go to next step 

1. Check the connector connections and contact pressure of the relevant terminals for the water pump with motor assembly connectors.
   Fig 1: Identifying Water Pump With Motor Assembly Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK

   The connectors are connected securely and there are no contact pressure problems.

NG → CONNECT SECURELY 

OK: Go to next step 

1. Disconnect the power management control ECU connector.
2. Disconnect the water pump with motor assembly connector.
3. Measure the resistance according to the value(s) in the table below.
   Fig 2: Measuring Resistance Of Power Management Control ECU - Water Pump With Motor Assembly Harness & Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   TEXT IN ILLUSTRATION
   
   

   *a

   Rear view of wire harness connector (to Power Management Control ECU)

   *b

   Front view of wire harness connector (to Water Pump with Motor Assembly)

   Standard Resistance (Check for Open)

   Tester Connection	Switch Condition	Specified Condition
   A39-3 (SWP) - A23-26 (IWP)	Power switch off	Below 1 Ω

   Standard Resistance (Check for Short)

   Tester Connection	Switch Condition	Specified Condition
   A39-3 or A23-26 (IWP) - Body ground and other terminals	Power switch off	10 kΩ or higher

4. Reconnect the power management control ECU connector.
5. Reconnect the water pump with motor assembly connector.

NG → REPAIR OR REPLACE HARNESS AND CONNECTOR 

OK: Go to next step 

HINT: 

When the auxiliary battery voltage is low, the water pump with motor assembly may not operate.

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Enter the following menus: Powertrain / EV / Data List.
4. Select Inverter Water Pump Revolution in the Data List.
5. Remove the INV W/P fuse from the No. 2 motor compartment relay block.
   Fig 3: Identifying INV W/P Fuse On No. 2 Motor Compartment Relay Block

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
6. Read the Data List.

   Standard

   Techstream Display	Switch Condition	Specified Condition
   Inverter Water Pump Revolution	Power switch on (IG)	125 rpm or less

   TEXT IN ILLUSTRATION
   
   

   *1	No. 2 Motor Compartment Relay Block
   *2	INV W/P Fuse

7. Turn the power switch off.
8. Install the INV W/P fuse.

NG → See step   12 

OK: Go to next step 

1. Disconnect the power management control ECU connector.
2. Turn the power switch on (IG).
3. Measure the voltage according to the value(s) in the table below.
   Fig 4: Measuring Voltage Of Power Management Control ECU Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   A23-26 (IWP) - C21-24 (E1)	Power switch on (IG)	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *a	Rear view of wire harness connector (to Power Management Control ECU)

   NOTE:

   Turning the power switch on (IG) with the power management control ECU connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

4. Turn the power switch off.
5. Reconnect the power management control ECU connector.

NG → See step   13 

OK: Go to next step 

1. Turn the power switch on (IG).
2. While turning the power switch on (IG), check the waveform between the power management control ECU terminals.
   Fig 5: Identifying Power Management Control ECU Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Item	Content
   Terminal	A23-26 (IWP) - C21-24 (E1)
   Equipment Setting	5 V/DIV., 50 ms/DIV
   Switch Condition	Power switch on (IG)

   OK

   Waveform duty ratio is between 3% and 9%.

   TEXT IN ILLUSTRATION
   
   

   *a	Component with harness connected (Power Management Control ECU)

3. Turn the power switch off.

NG → See step   12 

OK → See step   13 

1. Even though it has been determined that the power management control ECU needs to be replaced, make sure to inspect the voltage difference between No. 1 EV battery and No. 2 EV battery before replacing it.

NEXT → See step   15