DTC P0C73-96: Motor Electronics Coolant Pump "A" Component Internal Failure [11/2022 - ]: Procedure

HINT: 

• When the auxiliary battery voltage is low, the inverter water pump assembly may not operate.
• When the inverter water pump assembly signal line (SWP - IWP) is open or its connection is faulty, the inverter water pump assembly is operated forcibly.

1. According to the display on the GTS, read the Data List.

   Powertrain > Hybrid Control > Data List 

   Tester Display
   Inverter Water Pump Revolution

   OK

   Tester Display	Condition	Specified Condition
   Inverter Water Pump Revolution	Ignition switch ON	200 rpm or less

   HINT: 

   When the inverter water pump assembly is not operating, the Data List item "Inverter Water Pump Revolution" displays a value 200 rpm or less.

2. Turn the ignition switch off.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  5

Result: 

OK 

See step  2

1. Read and record the DTCs and Freeze Frame Data.

   Powertrain > Hybrid Control > Trouble Codes 

2. Clear the DTCs and Freeze Frame Data.

   Powertrain > Hybrid Control > Clear DTCs 

3. Turn the ignition switch off and wait for 2 minutes or more.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  3

HINT: 

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

1. According to the display on the GTS, perform the Active Test "Activate the Inverter Water Pump" and, check the value of the Data List item "Inverter Water Pump Revolution".

   Powertrain > Hybrid Control > Active Test 

   Active Test Display
   Activate the Inverter Water Pump

   Data List Display
   Inverter Water Pump Revolution

   OK

   Tester Display	Condition	Specified Condition
   Inverter Water Pump Revolution	Ignition switch ON During Active Test	3000 to 9500 rpm

   HINT: 

   • Perform the Active Test with the inverter coolant temperature between -15 and 65°C (5 to 149°F).
   • When the inverter water pump assembly is not operating, the Data List item "Inverter Water Pump Revolution" displays a value 200 rpm or less.
2. Turn the ignition switch off.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  5

Result: 

OK 

See step  4

Refer to PROCEDURE - Step 7

Result

Result: 

A 

See step  11

Result: 

B 

REPLACE HV COOLANT 

Refer to REPLACEMENT [11/2022 - ]

Refer to PROCEDURE - Step 1

Result

Result: 

NG 

CONNECT SECURELY 

Result: 

OK 

See step  6

Refer to PROCEDURE - Step 9

Result

Result: 

NG 

CONNECT SECURELY 

Result: 

OK 

See step  7

1. Disconnect the hybrid vehicle control ECU connector.
2. Disconnect the inverter water pump assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance (Check for Open)

   Tester Connection	Condition	Specified Condition
   A192-32 (IWP) - A184-3 (SWP)	Ignition switch off	Below 1 Ω

   Standard Resistance (Check for Short)

   Tester Connection	Condition	Specified Condition
   A192-32 (IWP) or A184-3 (SWP) - Body ground and other terminals	Ignition switch off	10 kΩ or higher

   HINT: 

   Check the condition (looseness, deterioration, etc.) of the wire to body ground for the inverter water pump assembly.

4. Reconnect the inverter water pump assembly connector.
5. Reconnect the hybrid vehicle control ECU connector.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  8

HINT: 

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

1. Remove the INV W/PMP NO. 2 fuse from No. 1 engine room relay block and No. 1 junction block assembly.
2. According to the display on the GTS, read the Data List.

   Powertrain > Hybrid Control > Data List 

   Tester Display
   Inverter Water Pump Revolution

   OK

   Tester Display	Condition	Specified Condition
   Inverter Water Pump Revolution	Ignition switch ON	200 rpm or less

3. Turn the ignition switch off.
4. Install the INV W/PMP NO. 2 fuse.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE HYBRID VEHICLE CONTROL ECU 

Refer to REMOVAL [11/2022 - 12/2024] , or refer to REMOVAL [12/2024 - ]

Result: 

OK 

See step  9

1. Disconnect the hybrid vehicle control ECU connector.
2. Turn the ignition switch to ON.
3. Measure the voltage according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a

   Component with harness connected (Hybrid Vehicle Control ECU)

   *b

   Front view of wire harness connector (to Hybrid Vehicle Control ECU)

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A192-32 (IWP) - I249-1 (E1)	Ignition switch ON	11 to 14 V

   NOTE:

   Make sure to check for and clear DTCs after performing this inspection.

4. Turn the ignition switch off.
5. Reconnect the hybrid vehicle control ECU connector.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  11

Result: 

OK 

See step  10

1. Connect an oscilloscope between the hybrid vehicle control ECU terminals specified in the table below.
2. Turn the ignition switch to ON.
3. Check the waveform while turning the ignition switch to ON.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a

   Component with harness connected (Hybrid Vehicle Control ECU)

   -

   -

   Item	Content
   Terminal	A192-32 (IWP) - I249-1 (E1)
   Equipment Setting	5 V/DIV., 50 ms./DIV.
   Condition	Ignition switch ON

   OK

   Waveform duty ratio is between 3% and 9%.

4. Turn the ignition switch off.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE HYBRID VEHICLE CONTROL ECU 

Refer to REMOVAL [11/2022 - 12/2024] , or refer to REMOVAL [12/2024 - ]

Result: 

OK 

See step  11

Refer to REMOVAL [11/2022 - ]

Result

Result: 

NEXT 

See step  12

1. After replacing the inverter water pump assembly, add HV coolant and perform air bleeding.

   Refer to REPLACEMENT [11/2022 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

END