DTC P314A-31: Motor Electronics Coolant Pump "A" No Signal [09/2023 - ]: Procedure

Pre-procedure1

• None

• Clear the DTCs.

  Powertrain > Engine > Clear DTCs 

  Result

  Proceed to
  NEXT

Post-procedure1

• Turn the ignition switch off and wait for at least 30 seconds.

Result: 

NEXT 

See step  2

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 - IWPO) is open or its connection is faulty, the inverter water pump assembly is operated forcibly.

Pre-procedure1

• None

• Perform the "Control the Intercooler Water Pump" Active Test.

  Powertrain > Engine > Active Test 

  Active Test Display
  Control the Intercooler Water Pump

  Data List Display
  Intercooler Water Pump Speed
  Intercooler Water Pump

• Touch the inverter water pump assembly and check that it is operating (vibrating).

  OK

  The inverter water pump is operating (vibrating).

  HINT: 

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

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Turn the ignition switch off.

Result: 

NG 

See step  11

Result: 

OK 

See step  3

1. Check the connector connections and contact pressure of the relevant terminals for the ECM connectors.

   HINT: 

   Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [09/2023 - ]

   Refer to REMOVAL [09/2023 - ]

   OK

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

   Result

   Proceed to
   OK
   NG

Result: 

NG 

CONNECT SECURELY 

Result: 

OK 

See step  4

1. Check the connector connections and contact pressure of the relevant terminals for the inverter water pump assembly connector.

   HINT: 

   Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [09/2023 - ]

   Refer to REMOVAL [09/2023 - ]

   OK

   The connector is connected securely, the terminals are not deformed or corroded and there are no contact problems.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

CONNECT SECURELY 

Result: 

OK 

See step  5

Pre-procedure1

• Disconnect the ECM connector.
• Disconnect the inverter water pump assembly connector.

• Measure the resistance according to the value(s) in the table below.

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  C26-46 (IWPI) - C33-2 (NWP)	Ignition switch off	Below 1 Ω	Ω
  C26-46 (IWPI) or C33-2 (NWP) - Body ground and other terminals	Ignition switch off	10 kΩ or higher	kΩ

  HINT: 

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

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Reconnect the inverter water pump assembly connector.
• Reconnect the ECM connector.

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  6

Pre-procedure1

• Disconnect the inverter water pump assembly connector.
• Turn the ignition switch to ON.

• Measure the voltage according to the value(s) in the table below.

  Standard Voltage

  Tester Connection	Condition	Specified Condition	Result
  C33-2 (NWP) - Body ground	Ignition switch ON	11 to 14 V	V

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Turn the ignition switch off.
• Reconnect the inverter water pump assembly connector.

Result: 

NG 

REPLACE ECM. Refer to  REMOVAL [09/2023 - ] 

Result: 

OK 

See step  7

HINT: 

Refer to REMOVAL [09/2023 - ]

Result

Result: 

NEXT 

See step  8

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

   HINT: 

   Refer to REPLACEMENT [09/2023 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  9

Pre-procedure1

• None

• Clear the DTCs.

  Powertrain > Engine > Clear DTCs 

  Result

  Proceed to
  NEXT

Post-procedure1

• Turn the ignition switch off and wait for at least 30 seconds.

Result: 

NEXT 

See step  10

Pre-procedure1

• Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

• Read the DTCs.

  Powertrain > Engine > Trouble Codes 

  Result

  Result	Proceed to
  DTCs are not output	A
  P314A-31 is output	B

Post-procedure1

• Turn the ignition switch off.

Result: 

A 

END 

Result: 

B 

REPLACE ECM. Refer to  REMOVAL [09/2023 - ] 

1. Check the connector connections and contact pressure of the relevant terminals for the inverter water pump assembly connector.

   HINT: 

   Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [09/2023 - ]

   Refer to REMOVAL [09/2023 - ]

   OK

   The connector is connected securely, the terminals are not deformed or corroded and there are no contact problems.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

CONNECT SECURELY (INVERTER WATER PUMP ASSEMBLY CONNECTOR) 

Result: 

OK 

See step  12

1. Check installation condition of the INV W/PMP relay.

   OK

   INV W/PMP relay is installed correctly.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  19

Result: 

OK 

See step  13

Pre-procedure1

• Remove the EFI-MAIN NO. 1 relay from the No. 1 engine room relay block and No. 1 junction block assembly.
• Remove the INV W/PMP relay from the No. 1 engine room relay block and No. 1 junction block assembly.

• Measure the resistance according to the value(s) in the table below while shaking the connector, wire harness, and relay block.

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  5 (EFI-MAIN NO. 1 relay) - 1 (INV W/PMP relay)	Ignition switch off	Below 1 Ω	Ω

  NOTE:

  Do not apply excessive force when using the probes of the tester to perform the inspection. If excessive force is used, the terminals will be damaged.

  HINT: 

  • Connectors

    Slightly shake the connector vertically and horizontally.

  • Wire Harness

    Slightly shake the wire harness vertically and horizontally.

    The connector joint and fulcrum of the vibration are the major areas that should be checked thoroughly.

  • No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

    Apply slight vibration with a finger to the No. 1 engine room relay block and No. 1 junction block assembly and check whether a malfunction occurs.

  • INV W/PMP NO. 1 fuse

    Apply slight vibration with a finger to the INV W/PMP NO. 1 fuse and check whether a malfunction occurs.

  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

  *a	Example
  *b	Shake Slightly
  *c	Vibrate Slightly

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Install the EFI-MAIN NO. 1 relay and INV W/PMP relay.

Result: 

NG 

See step  20

Result: 

OK 

See step  14

Pre-procedure1

• Remove the INV W/PMP relay from the No. 1 engine room relay block and No. 1 junction block assembly.

• Measure the resistance according to the value(s) in the table below.

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  3 - 5	Auxiliary battery voltage not applied between terminals 1 and 2	10 kΩ or higher	kΩ
  3 - 5	Auxiliary battery voltage applied between terminals 1 and 2	Below 1 Ω	Ω

  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

  *1	INV W/PMP Relay

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Install the INV W/PMP relay.

Result: 

NG 

See step  22

Result: 

OK 

See step  15

Pre-procedure1

• Disconnect the inverter water pump assembly connector.
• Turn the ignition switch to ON.

• Measure the voltage according to the value(s) in the table below while shaking the connector, wire harness, and relay block.

  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

  *a	Example
  *b	Shake Slightly
  *c	Vibrate Slightly

  Standard Voltage

  Tester Connection	Condition	Specified Condition	Result
  C33-4 (+BWP) - Body ground	Ignition switch ON	11 to 14 V	V

  NOTE:

  • If the ignition switch is turned to ON with the connectors disconnected, other DTCs will be stored. Be sure to clear the DTCs after the inspection.
  • Do not apply excessive force when using the probes of the tester to perform the inspection. If excessive force is used, the terminals will be damaged.

  HINT: 

  • Connectors

    Slightly shake the connector vertically and horizontally.

  • Wire Harness

    Slightly shake the wire harness vertically and horizontally.

    The connector joint and fulcrum of the vibration are the major areas that should be checked thoroughly.

  • No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

    Apply slight vibration with a finger to the No. 1 engine room relay block and No. 1 junction block assembly and check whether a malfunction occurs.

  • INV W/PMP NO. 2 fuse

    Apply slight vibration with a finger to the INV W/PMP NO. 2 fuse and check whether a malfunction occurs.

  • INV W/PMP Relay

    Apply slight vibration with a finger to the INV W/PMP relay and check whether a malfunction occurs.

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Turn the ignition switch off.
• Reconnect the inverter water pump assembly connector.

Result: 

NG 

See step  23

Result: 

OK 

See step  16

Pre-procedure1

• Disconnect the inverter water pump assembly connector.

• Measure the resistance according to the value(s) in the table below.

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  C33-1 (GND) - Body ground	Ignition switch off	Below 1 Ω	Ω

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Reconnect the inverter water pump assembly connector.

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  17

HINT: 

Refer to REMOVAL [09/2023 - ]

Result

Result: 

NEXT 

See step  18

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

   HINT: 

   Refer to REPLACEMENT [09/2023 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

END 

Pre-procedure1

• Remove the INV W/PMP relay from the No. 1 engine room relay block and No. 1 junction block assembly.

• Measure the resistance according to the value(s) in the table below.

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  3 - 5	Auxiliary battery voltage not applied between terminals 1 and 2	10 kΩ or higher	kΩ
  3 - 5	Auxiliary battery voltage applied between terminals 1 and 2	Below 1 Ω	Ω

  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

  *1	INV W/PMP Relay

  Result

  Proceed to
  OK
  NG

• Install the INV W/PMP relay.

Post-procedure1

Result: 

OK 

CONNECT SECURELY (INV W/PMP RELAY) 

Result: 

NG 

REPLACE RELAY (INV W/PMP) 

1. Check installation condition of the INV W/PMP NO. 1 fuse.

   OK

   INV W/PMP NO. 1 fuse is installed correctly.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  27

Result: 

OK 

See step  21

Pre-procedure1

• Remove the INV W/PMP NO. 1 fuse from theNo. 1 engine room relay block and No. 1 junction block assembly.

• Measure the resistance according to the value(s) in the table below.

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  INV W/PMP NO. 1 fuse	Always	Below 1 Ω	Ω

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Install the INV W/PMP NO. 1 fuse.

Result: 

OK 

REPAIR OR REPLACE HARNESS OR CONNECTOR (INV W/PMP NO. 1 FUSE HOLDER TERMINAL) 

Result: 

NG 

See step  28

1. Check the terminals of the INV W/PMP relay holder.

   OK

   The terminals of the INV W/PMP relay holder are not bent, loose or corroded.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE RELAY (INV W/PMP) 

Result: 

NG 

See step  29

1. Check installation condition of the INV W/PMP NO. 2 fuse.

   OK

   INV W/PMP NO. 2 fuse is installed correctly.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

CONNECT SECURELY (INV W/PMP NO. 2 FUSE) 

Result: 

OK 

See step  24

Pre-procedure1

• Remove the INV W/PMP relay from the No. 1 engine room relay block and No. 1 junction block assembly.

• Measure the resistance according to the value(s) in the table below.

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  3 - 5	Auxiliary battery voltage not applied between terminals 1 and 2	10 kΩ or higher	kΩ
  3 - 5	Auxiliary battery voltage applied between terminals 1 and 2	Below 1 Ω	Ω

  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

  *1	INV W/PMP Relay

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Install the INV W/PMP relay.

Result: 

NG 

See step  34

Result: 

OK 

See step  25

Pre-procedure1

• Remove the INV W/PMP NO. 2 fuse from the No. 1 engine room relay block and No. 1 junction block assembly.
• Remove the INV W/PMP relay from theNo. 1 engine room relay block and No. 1 junction block assembly.
• Disconnect the inverter water pump assembly connector.

• Measure the resistance according to the value(s) in the table below.

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  C33-4 (+BWP) - 3 (INV W/PMP relay)	Ignition switch off	Below 1 Ω	Ω
  2 (INV W/PMP NO. 2 fuse) - 5 (INV W/PMP relay)	Ignition switch off	Below 1 Ω	Ω
  2 (INV W/PMP NO. 2 fuse) or C33-4 (+BWP) - Body ground and other terminals	Ignition switch off	10 kΩ or higher	kΩ

  NOTE:

  Do not apply excessive force when using the probes of the tester to perform the inspection. If excessive force is used, the terminals will be damaged.

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Reconnect the inverter water pump assembly connector.
• Install the INV W/PMP relay and INV W/PMP NO. 2 fuse.

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  26

Pre-procedure1

• Remove the INV W/PMP NO. 2 fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

• Measure the resistance according to the value(s) in the table below.

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  INV W/PMP NO. 2 fuse	Always	Below 1 Ω	Ω

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Install the INV W/PMP NO. 2 fuse.

Result: 

OK 

REPAIR OR REPLACE HARNESS OR CONNECTOR (INV W/PMP NO. 2 FUSE HOLDER TERMINAL OR INV W/PMP RELAY HOLDER TERMINAL) 

Result: 

NG 

See step  30

Pre-procedure1

• Remove the INV W/PMP relay from the No. 1 engine room relay block and No. 1 junction block assembly.

• Measure the resistance according to the value(s) in the table below.

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  3 - 5	Auxiliary battery voltage not applied between terminals 1 and 2	10 kΩ or higher	kΩ
  3 - 5	Auxiliary battery voltage applied between terminals 1 and 2	Below 1 Ω	Ω

  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

  *1	INV W/PMP Relay

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Install the INV W/PMP relay.

Result: 

OK 

CONNECT SECURELY (INV W/PMP NO. 1 FUSE) 

Result: 

NG 

See step  32

1. Check the terminals of the INV W/PMP NO. 1 fuse holder.

   OK

   The terminals of the INV W/PMP NO. 1 fuse holder are not bent, loose or corroded.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE FUSE (INV W/PMP NO. 1) 

Result: 

NG 

See step  33

1. Repair or replace the terminals of the INV W/PMP relay holder.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

REPLACE RELAY (INV W/PMP) 

HINT: 

Refer to REMOVAL [09/2023 - ]

Result

Result: 

NEXT 

See step  31

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

   HINT: 

   Refer to REPLACEMENT [09/2023 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

REPLACE FUSE (INV W/PMP NO. 2) 

Result

Result: 

NEXT 

CONNECT SECURELY (INV W/PMP NO. 1 FUSE) 

1. Repair or replace the terminals of the INV W/PMP NO. 1 fuse holder.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

REPLACE FUSE (INV W/PMP NO. 1) 

1. Check the terminals of the INV W/PMP relay holder.

   OK

   The terminals of the INV W/PMP relay holder are not bent, loose or corroded.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  36

Result: 

OK 

See step  35

Pre-procedure1

• Remove the INV W/PMP NO. 2 fuse from No. 1 engine room relay block and No. 1 junction block assembly.

• Measure the resistance according to the value(s) in the table below.

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  INV W/PMP NO. 2 fuse	Always	Below 1 Ω	Ω

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Install the INV W/PMP NO. 2 fuse.

Result: 

OK 

REPLACE RELAY (INV W/PMP) 

Result: 

NG 

See step  38

Pre-procedure1

• Remove the INV W/PMP NO. 2 fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

• Measure the resistance according to the value(s) in the table below.

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  INV W/PMP NO. 2 fuse	Always	Below 1 Ω	Ω

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Install the INV W/PMP NO. 2 fuse.

Result: 

NG 

See step  39

Result: 

OK 

See step  37

1. Repair or replace the terminals of the INV W/PMP relay holder.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

REPLACE RELAY (INV W/PMP) 

Result

Result: 

NEXT 

REPLACE FUSE (INV W/PMP NO. 2) 

1. Repair or replace the terminals of the INV W/PMP relay holder.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  40

Result

Result: 

NEXT 

REPLACE FUSE (INV W/PMP NO. 2)