Lexus ES: Motor Electronics Coolant Pump "A" Component Internal Failure (P0C7396)

DTC SUMMARY

MALFUNCTION DESCRIPTION

This DTC is stored when the inverter water pump assembly is malfunctioning. The cause of this malfunction may be one of the following:

HINT:

If this DTC is stored, the driving torque may be restricted.

DESCRIPTION

The inverter water pump assembly transmits rotation speed information to the hybrid vehicle control ECU. The hybrid vehicle control ECU monitors the speed and detects malfunctions.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Warning Indicate
P0C7396	Motor Electronics Coolant Pump "A" Component Internal Failure	The inverter water pump assembly revolution speed is abnormally high or low (or stopped) for 1 minute or more. (1 trip detection logic)	Inverter cooling system Wire harness or connector Inverter water pump assembly Hybrid vehicle control ECU	Comes on	Master Warning Light: Comes on

HINT:

The inverter water pump assembly operates when the power switch is on (READY).

Related Data List

DTC No.	Data List
P0C7396	Inverter Water Pump Revolution Inverter Water Pump Duty Ratio Inverter Coolant Water Temperature

Related Active Test

DTC No.	Active Test
P0C7396	Activate the Inverter Water Pump

MONITOR DESCRIPTION

The hybrid vehicle control ECU monitors speed of the inverter water pump assembly. If there is an abnormality in speed, the hybrid vehicle control ECU will illuminate the MIL and store a DTC.

MONITOR STRATEGY

Related DTCs	P0C73 (INF P0C7396): Motor Electronics Coolant Pump "A" malfunction
Required sensors/components	Inverter water pump assembly
Frequency of operation	Continuous
Duration	TMC's intellectual property
MIL operation	1 driving cycle
Sequence of operation	None

TYPICAL ENABLING CONDITIONS

The monitor will run whenever the following DTCs are not stored	TMC's intellectual property
Other conditions belong to TMC's intellectual property	-

TYPICAL MALFUNCTION THRESHOLDS

TMC's intellectual property

-

COMPONENT OPERATING RANGE

Hybrid vehicle control ECU

DTC P0C73 (INF P0C7396) is not detected

CONFIRMATION DRIVING PATTERN

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

If this vehicle is jump started, etc. and excessive voltage is applied to the auxiliary battery, the inverter water pump assembly may suspend control as a self-protection function and store DTCs.

(When the auxiliary battery voltage returns to normal, the inverter water pump assembly will resume normal operation. In this case it is not necessary to replace the inverter water pump assembly.)

PROCEDURE

1.	CHECK DTC OUTPUT (HYBRID CONTROL)

(a) Connect the Techstream to the DLC3.

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

(c) Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

(d) Check for DTCs.

Powertrain > Hybrid Control > Trouble Codes

Result	Proceed to
P0C7396 only is output, or DTCs except the ones in the table below are also output.	A
Any of the following DTCs including pending DTCs are also output.	B

Malfunction Content	Relevant DTC
Microcomputer malfunction	P060647	Hybrid/EV Powertrain Control Module Processor Watchdog / Safety MCU Failure
	P06881F	ECM/PCM Power Relay Sense Circuit Intermittent
Sensor and actuator circuit malfunction	P314A31	Motor Electronics Coolant Pump "A" No Signal

HINT:

P0C7396 may be output as a result of the malfunction indicated by the DTCs above.

(e) Turn the power switch off.

B

GO TO DTC CHART (HYBRID CONTROL SYSTEM)

A

2.	READ VALUE USING TECHSTREAM (INVERTER WATER PUMP REVOLUTION)

NOTICE:

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

(a) Connect the Techstream to the DLC3.

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

(c) Enter the following menus: Powertrain / Hybrid Control / Data List / Inverter Water Pump Revolution.

Powertrain > Hybrid Control > Data List

Tester Display
Inverter Water Pump Revolution

(d) According to the display on the Techstream, read the Data List.

OK:

Tester Display	Condition	Specified Condition
Inverter Water Pump Revolution	Power switch on (IG)	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.

(e) Turn the power switch off.

NG

GO TO STEP 6

OK

3.

CLEAR DTC

Click here

NEXT

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

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).

(c) Enter the following menus: Powertrain / Hybrid Control / Active Test / Activate the Inverter Water Pump.

(d) Select 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

(e) According to the display on the Techstream, perform the Active Test "Activate the Inverter Water Pump" and, check the value of the Data List item "Inverter Water Pump Revolution".

OK:

Tester Display	Condition	Specified Condition
Inverter Water Pump Revolution	Power switch on (IG) During Active Test	3176 to 8617 rpm

(f) Turn the power switch off.

NG

GO TO STEP 6

OK

5.	CHECK HV COOLANT (CHECK FOR CONDITIONS THAT MAY HAVE CAUSED FREEZING)

Click here

Result	Proceed to
Ambient Temperature value is above freezing temperature of the HV coolant.	A
Ambient Temperature value is below freezing temperature of the HV coolant.	B

A

GO TO STEP 12

B

REPLACE HV COOLANT

6.	CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU CONNECTOR)

Click here

NG

CONNECT SECURELY

OK

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

Click here

NG

CONNECT SECURELY

OK

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

(a) Disconnect the A32 hybrid vehicle control ECU connector.

(b) Disconnect the Z1 inverter water pump assembly connector.

(c) Measure the resistance according to the value(s) in the table below. Standard Resistance (Check for Open): Tester Connection Condition Specified Condition A32-13 (IWP) - Z1-3 (SWP) Power switch off Below 1 Ω Standard Resistance (Check for Short): Tester Connection Condition Specified Condition A32-13 (IWP) or Z1-3 (SWP) - Body ground and other terminals Power 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.

*a Rear view of wire harness connector (to Hybrid Vehicle Control ECU) *b Front view of wire harness connector (to Inverter Water Pump Assembly)

(d) Reconnect the Z1 inverter water pump assembly connector.

(e) Reconnect the A32 hybrid vehicle control ECU connector.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

9.	READ VALUE USING TECHSTREAM (INVERTER WATER PUMP REVOLUTION)

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) Remove the INV W/PMP fuse from No. 4 relay block.

*1 No. 4 Relay Block *2 INV W/PMP Fuse

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

(d) Enter the following menus: Powertrain / Hybrid Control / Data List / Inverter Water Pump Revolution.

Powertrain > Hybrid Control > Data List

Tester Display
Inverter Water Pump Revolution

(e) According to the display on the Techstream, read the Data List.

OK:

Tester Display	Condition	Specified Condition
Inverter Water Pump Revolution	Power switch on (IG)	200 rpm or less

(f) Turn the power switch off.

(g) Install the INV W/PMP fuse.

NG

REPLACE HYBRID VEHICLE CONTROL ECU

OK

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

(a) Disconnect the A32 hybrid vehicle control ECU connector.

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

(c) Measure the voltage according to the value(s) in the table below. Standard Voltage: Tester Connection Condition Specified Condition A32-13 (IWP) - G59-6 (E1) Power switch on (IG) 11 to 14 V NOTICE: Turning the power switch on (IG) with the hybrid vehicle control ECU connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

*a Component with harness connected (Hybrid Vehicle Control ECU) *b Rear view of wire harness connector (to Hybrid Vehicle Control ECU)

(d) Turn the power switch off.

(e) Reconnect the A32 hybrid vehicle control ECU connector.

NG

GO TO STEP 12

OK

11.	CHECK HYBRID VEHICLE CONTROL ECU (CHECK WAVEFORM)

(a) Connect an oscilloscope between the hybrid vehicle control ECU terminals specified in the table below.

(b) Check the waveform while turning the power switch on (IG). Item Content Terminal A32-13 (IWP) - G59-6 (E1) Equipment Setting 5 V/DIV., 50 ms./DIV. Condition Power switch on (IG) OK: Waveform duty ratio is between 3% and 9%.

*a Component with harness connected (Hybrid Vehicle Control ECU)

(c) Turn the power switch off.

NG

REPLACE HYBRID VEHICLE CONTROL ECU

OK

12.	REPLACE INVERTER WATER PUMP ASSEMBLY

Click here

NEXT

13.	ADD HV COOLANT AND PERFORM AIR BLEEDING

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

Click here

NEXT

END

READ NEXT: