HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for 2WD with NICKEL METAL HYDRIDE BATTERY): P314A31; Motor Electronics Coolant Pump "A" No Signal; 2019 - 2020 MY RAV4 HV [11/2018

Last Modified: 01-30-2024	6.11:8.1.0	Doc ID: RM100000001EKLA
Model Year Start: 2019	Model: RAV4 HV	Prod Date Range: [11/2018 - 08/2020]
Title: HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for 2WD with NICKEL METAL HYDRIDE BATTERY): P314A31; Motor Electronics Coolant Pump "A" No Signal; 2019 - 2020 MY RAV4 HV [11/2018 - 08/2020]

DTC

P314A31

Motor Electronics Coolant Pump "A" No Signal

DESCRIPTION

Refer to the description for DTC P0C7396.

Click here

The inverter water pump assembly sends the inverter water pump speed (measured value) signal to the hybrid vehicle control ECU assembly.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

P314A31

Motor Electronics Coolant Pump "A" No Signal

The inverter water pump speed signal is not sent to the hybrid vehicle control ECU assembly when the power switch is turned on (READY).*

(1 trip detection logic)

Wire harness or connector
Hybrid vehicle control ECU assembly
Inverter water pump assembly
INV W/P NO. 1 fuse
INV W/P NO. 2 fuse
INV W/P relay

Comes on

Master Warning:

Comes on

*: Any of the following conditions is met.

A malfunction (open, short to +B or short to ground) in the speed signal line from the inverter water pump assembly to the hybrid vehicle control ECU assembly is detected.
A malfunction in the +B line is detected.
A malfunction in the inverter water pump assembly power source circuit is detected.
A malfunction in hybrid vehicle control ECU assembly power source circuit is detected.

Related Data List

DTC No.	Data List
P314A31	Inverter Water Pump Revolution Inverter Water Pump Duty Ratio Ready Signal

Related Active Test

DTC No.	Active Test
P314A31	Activate the Inverter Water Pump

CONFIRMATION DRIVING PATTERN

HINT:

After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.

Click here

Connect the Techstream to the DLC3.
Turn the power switch on (IG) and turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the power switch off and wait for 2 minutes or more.
Turn the power switch on (IG) and turn the Techstream on.
Turn the power switch on (READY) and wait for 2 minutes or more.
Enter the following menus: Powertrain / Hybrid Control / Utility / All Readiness.
Check the DTC judgment result.
HINT:
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows INCOMPLETE, perform driving pattern again.

WIRING DIAGRAM

Refer to the wiring diagram for DTC P0C7396.

Click here

PROCEDURE

CLEAR DTC

Click here

2.	PERFORM ACTIVE TEST USING TECHSTREAM (ACTIVATE THE INVERTER WATER PUMP)

NOTICE:

Make sure that the HV coolant level is above the low line of the inverter reserve tank.
Be sure to perform the inspection with the auxiliary battery voltage at 12 V or more.

HINT:

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

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(d) Perform the "Activate the Inverter Water Pump" Active Test.

Powertrain > Hybrid Control > Active Test

Tester Display
Activate the Inverter Water Pump

(e) 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).

(f) Turn the power switch off.

GO TO STEP 9

3.	CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU ASSEMBLY CONNECTOR)

Click here

CONNECT SECURELY

4.	CHECK CONNECTOR CONNECTION CONDITION (INVERTER WATER PUMP ASSEMBLY CONNECTOR)

Click here

CONNECT SECURELY

5.	CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU ASSEMBLY - INVERTER WATER PUMP ASSEMBLY)

(a) Disconnect the A29 hybrid vehicle control ECU assembly connector.

(b) Disconnect the A53 inverter water pump assembly connector.

Standard Resistance (Check for Open):

Tester Connection	Condition	Specified Condition
A29-33 (NIWP) - A53-2 (NWP)	Power switch off	Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection	Condition	Specified Condition
A29-33 (NIWP) or A53-2 (NWP) - Body ground and other terminals	Power switch off	10 kΩ or higher

Front view of wire harness connector

(to Hybrid Vehicle Control ECU assembly)

Front view of wire harness connector

(to Inverter Water Pump Assembly)

(d) Reconnect the A53 inverter water pump assembly connector.

(e) Reconnect the A29 hybrid vehicle control ECU assembly connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR

6.	CHECK HYBRID VEHICLE CONTROL ECU ASSEMBLY

(a) Disconnect the A53 inverter water pump assembly connector.

(b) Turn the power switch on (IG).

Component with harness connected

(Hybrid Vehicle Control ECU Assembly)

Standard Voltage:

Tester Connection	Condition	Specified Condition
A29-33 (NIWP) - A30-3 (E1)	Power switch on (IG)	11 to 14 V

(d) Turn the power switch off.

(e) Reconnect the A53 inverter water pump assembly connector.

REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY

CLEAR DTC

Click here

8.	PERFORM ACTIVE TEST USING TECHSTREAM (ACTIVATE THE INVERTER WATER PUMP)

NOTICE:

Be sure to perform the inspection with the auxiliary battery voltage at 12 V or more.

HINT:

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

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(d) Perform the "Activate the Inverter Water Pump" Active Test.

Powertrain > Hybrid Control > Active Test

Tester Display
Activate the Inverter Water Pump

(e) Connect an oscilloscope between the hybrid vehicle control ECU assembly terminals specified in the table below, and measure the waveform.

Component with harness connected

(Hybrid Vehicle Control ECU Assembly)

Item	Content
Terminal	A29-33 (NIWP) - A30-3 (E1)
Equipment Setting	5 V/DIV., 5 ms./DIV.
Condition	Power switch on (IG), during Active Test

OK:

The period of the wavelength is 13 msec or less.

(f) Turn the power switch off.

REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY

GO TO STEP 15

9.	CHECK CONNECTOR CONNECTION CONDITION (INVERTER WATER PUMP ASSEMBLY CONNECTOR)

Click here

CONNECT SECURELY (INVERTER WATER PUMP ASSEMBLY CONNECTOR)

10.	CHECK INSTALLATION CONDITION (INV W/P RELAY)

(a) Check installation condition of the INV W/P relay.

OK:

INV W/P relay is installed correctly.

*1	No. 1 Engine Room Relay Block and Junction Block Assembly
*2	INV W/P Relay

GO TO STEP 17

11.	CHECK HARNESS AND CONNECTOR (IGCT RELAY - INV W/P RELAY)

(a) Remove the IGCT relay from the No. 3 relay block and junction block assembly.

*1	No. 3 Relay Block and Junction Block Assembly
*2	IGCT Relay

(b) Remove the INV W/P relay from the No. 1 engine room relay block and junction block assembly.

*1	No. 1 Engine Room Relay Block and Junction Block Assembly
*2	INV W/P Relay

Standard Resistance:

Tester Connection	Condition	Specified Condition
5 (IGCT relay) - 1 (INV W/P relay)	Power switch off	Below 1 Ω

NOTICE:

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. 3 Relay Block and Junction Block Assembly
Apply slight vibration with a finger to the No. 3 relay block and junction block assembly and check whether a malfunction occurs.
No. 1 Engine Room Relay Block and Junction Block Assembly
Apply slight vibration with a finger to the No. 1 engine room relay block and junction block assembly and check whether a malfunction occurs.
INV W/P NO. 1 fuse
Apply slight vibration with a finger to the INV W/P NO. 1 fuse and check whether a malfunction occurs.

*a	Example
*b	Shake Slightly
*c	Vibrate Slightly

(d) Install the IGCT relay and INV W/P relay.

GO TO STEP 18

12.	INSPECT RELAY (INV W/P)

(a) Remove the INV W/P relay from the No. 1 engine room relay block and junction block assembly.

*1	No. 1 Engine Room Relay Block and Junction Block Assembly
*2	INV W/P Relay

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

Standard Resistance:

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

*1	INV W/P Relay

GO TO STEP 20

13.	CHECK HARNESS AND CONNECTOR (INVERTER WATER PUMP ASSEMBLY - BODY GROUND)

*a	Front view of wire harness connector (to Inverter Water Pump Assembly)

*a	Example
*b	Shake Slightly
*c	Vibrate Slightly

(a) Disconnect the A53 inverter water pump assembly connector.

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
A53-4 (+BWP) - Body ground	Power switch on (IG)	11 to 14 V

NOTICE:

If the power switch is turned on (IG) 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 Junction Block Assembly
Apply slight vibration with a finger to the No. 1 engine room relay block and junction block assembly and check whether a malfunction occurs.
INV W/P NO. 2 fuse
Apply slight vibration with a finger to the INV W/P NO. 2 fuse and check whether a malfunction occurs.
INV W/P Relay
Apply slight vibration with a finger to the INV W/P relay and check whether a malfunction occurs.

GO TO STEP 21

14.	CHECK HARNESS AND CONNECTOR (INVERTER WATER PUMP ASSEMBLY - BODY GROUND)

(a) Disconnect the A53 inverter water pump assembly connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A53-1 (GND) - Body ground	Power switch off	Below 1 Ω

*a	Front view of wire harness connector (to Inverter Water Pump Assembly)

REPAIR OR REPLACE HARNESS OR CONNECTOR

15.	REPLACE INVERTER WATER PUMP ASSEMBLY

Click here

16.	ADD HV COOLANT AND PERFORM AIR BLEEDING

(a) After replacing the inverter water pump with motor assembly, add HV coolant and perform air bleeding.

Click here

END

17.	INSPECT RELAY (INV W/P)

(a) Remove the INV W/P relay from the No. 1 engine room relay block and junction block assembly.

*1	No. 1 Engine Room Relay Block and Junction Block Assembly
*2	INV W/P Relay

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

Standard Resistance:

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

*1	INV W/P Relay

CONNECT SECURELY (INV W/P RELAY)

REPLACE RELAY (INV W/P)

18.	CHECK INSTALLATION CONDITION (INV W/P NO. 1 FUSE)

(a) Check installation condition of the INV W/P NO. 1 fuse.

OK:

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

*1	No. 3 Relay Block and Junction Block Assembly
*2	INV W/P NO. 1 Fuse

GO TO STEP 25

19.	CHECK FUSE (INV W/P NO. 1)

(a) Remove the INV W/P NO. 1 fuse from the No. 3 relay block and junction block assembly.

*1	No. 3 Relay Block and Junction Block Assembly
*2	INV W/P NO. 1 Fuse

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

Standard Resistance:

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

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

GO TO STEP 26

20.	CHECK RELAY HOLDER TERMINAL (INV W/P RELAY)

(a) Check the terminals of the INV W/P relay holder.

OK:

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

*1	No. 1 Engine Room Relay Block and Junction Block Assembly
*2	INV W/P Relay

REPLACE RELAY (INV W/P)

GO TO STEP 27

21.	CHECK INSTALLATION CONDITION (INV W/P NO. 2 FUSE)

(a) Check installation condition of the INV W/P NO. 2 fuse.

OK:

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

*1	No. 1 Engine Room Relay Block and Junction Block Assembly
*2	INV W/P NO. 2 Fuse

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

22.	INSPECT RELAY (INV W/P)

(a) Remove the INV W/P relay from the No. 1 engine room relay block and junction block assembly.

*1	No. 1 Engine Room Relay Block and Junction Block Assembly
*2	INV W/P Relay

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

Standard Resistance:

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

*1	INV W/P Relay

GO TO STEP 32

23.	CHECK HARNESS AND CONNECTOR (INVERTER WATER PUMP ASSEMBLY CIRCUIT)

(a) Remove the INV W/P relay and INV W/P NO. 2 fuse from the No. 1 engine room relay block and junction block assembly.

(b) Disconnect the A53 inverter water pump assembly connector.

No. 1 Engine Room Relay Block and Junction Block Assembly

INV W/P NO. 2 Fuse

INV W/P Relay

Front view of wire harness connector

(to Inverter Water Pump Assembly)

Standard Resistance:

Tester Connection	Condition	Specified Condition
A53-4 (+BWP) - 3 (INV W/P relay)	Power switch off	Below 1 Ω
2 (INV W/P NO. 2 fuse) or A53-4 (+BWP) - Body ground and other terminals	Power switch off	10 kΩ or higher

NOTICE:

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.

(d) Reconnect the A53 inverter water pump assembly connector.

(e) Install the INV W/P relay and INV W/P NO. 2 fuse.

REPAIR OR REPLACE HARNESS OR CONNECTOR

24.	CHECK FUSE (INV W/P NO. 2)

(a) Remove the INV W/P NO. 2 fuse from the No. 1 engine room relay block and junction block assembly.

*1	No. 1 Engine Room Relay Block and Junction Block Assembly
*2	INV W/P NO. 2 Fuse

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

Standard Resistance:

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

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

GO TO STEP 28

25.	INSPECT RELAY (INV W/P)

(a) Remove the INV W/P relay from the No. 1 engine room relay block and junction block assembly.

*1	No. 1 Engine Room Relay Block and Junction Block Assembly
*2	INV W/P Relay

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

Standard Resistance:

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

*1	INV W/P Relay

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

GO TO STEP 30

26.	CHECK FUSE HOLDER TERMINAL (INV W/P NO. 1 FUSE)

(a) Check the terminals of the INV W/P NO. 1 fuse holder.

OK:

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

*1	No. 3 Relay Block and Junction Block Assembly
*2	INV W/P NO. 1 Fuse

REPLACE FUSE (INV W/P NO.1)

GO TO STEP 31

27.	REPAIR OR REPLACE HARNESS OR CONNECTOR (INV W/P RELAY HOLDER TERMINAL)

(a) Repair or replace the terminals of the INV W/P relay holder.

REPLACE RELAY (INV W/P)

28.	REPLACE INVERTER WATER PUMP ASSEMBLY

Click here

29.	ADD HV COOLANT AND PERFORM AIR BLEEDING

(a) After replacing the inverter water pump with motor assembly, add HV coolant and perform air bleeding.

Click here

REPLACE FUSE (INV W/P NO. 2)

30.	REPLACE RELAY (INV W/P)

(a) Replace INV W/P relay.

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

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

REPLACE FUSE (INV W/P NO.1)

32.	CHECK RELAY HOLDER TERMINAL (INV W/P RELAY)

(a) Check the terminals of the INV W/P relay holder.

OK:

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

*1	No. 1 Engine Room Relay Block and Junction Block Assembly
*2	INV W/P Relay

GO TO STEP 34

33.	CHECK FUSE (INV W/P NO. 1)

(a) Remove the INV W/P NO. 1 fuse from the No. 3 relay block and junction block assembly.

*1	No. 3 Relay Block and Junction Block Assembly
*2	INV W/P NO. 1 Fuse

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

Standard Resistance:

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

REPLACE RELAY (INV W/P)

GO TO STEP 36

34.	CHECK FUSE (INV W/P NO. 1)

(a) Remove the INV W/P NO. 1 fuse from the No. 3 relay block and junction block assembly.

*1	No. 3 Relay Block and Junction Block Assembly
*2	INV W/P NO. 1 Fuse

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

Standard Resistance:

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

GO TO STEP 37

35.	REPAIR OR REPLACE HARNESS OR CONNECTOR (INV W/P RELAY HOLDER TERMINAL)

(a) Repair or replace the terminals of the INV W/P relay holder.

REPLACE RELAY (INV W/P)

36.	REPLACE RELAY (INV W/P)

(a) Replace INV W/P relay.

REPLACE FUSE (INV W/P NO. 1)

37.	REPAIR OR REPLACE HARNESS OR CONNECTOR (INV W/P RELAY HOLDER TERMINAL)

(a) Repair or replace the terminals of the INV W/P relay holder.

38.	REPLACE RELAY (INV W/P)

(a) Replace INV W/P relay.

REPLACE FUSE (INV W/P NO. 1)