Toyota Avalon (XX50): DC/DC Converter Enable Circuit Short to Battery (P0A1112,P0A1114). Drive Motor "A" Inverter Actuator Stuck Open (P0A7872). Drive Motor "A" Inverter Actuator Stuck Closed (P0A7873)

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual / Engine / Hybrid / Battery Control / Motor Generator Control System / DC/DC Converter Enable Circuit Short to Battery (P0A1112,P0A1114). Drive Motor "A" Inverter Actuator Stuck Open (P0A7872). Drive Motor "A" Inverter Actuator Stuck Closed (P0A7873)

DC/DC Converter Enable Circuit Short to Battery (P0A1112,P0A1114)

DESCRIPTION

Refer to the description for DTC P1CCC96.

Click here

The motor generator control ECU sends a signal to the DC/DC converter to prohibit its control and receives signals indicating a normal or abnormal (below 11 V) condition of the 12 V charging system from the DC/DC converter via the NODD signal line.

If the vehicle is being driven with an inoperative DC/DC converter, the voltage of the auxiliary battery will drop, which will prevent the continued operation of the vehicle. Therefore, the motor generator control ECU monitors the operation of the DC/DC converter and alerts the driver if it detects a malfunction.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Warning Indicate
P0A1112	DC/DC Converter Enable Circuit Short to Battery	Short to +B detected in DC/DC converter NODD signal line (1 trip detection logic)	Wire harness or connector Inverter with converter assembly	Does not come on	Master Warning Light: Comes on
P0A1114	DC/DC Converter Enable Circuit Short to Ground or Open	Open or short to ground detected in DC/DC converter NODD signal line (1 trip detection logic)	Wire harness or connector Inverter with converter assembly	Does not come on	Master Warning Light: Comes on

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

P0A1112

DC/DC Converter Enable Circuit Short to Battery

Short to +B detected in DC/DC converter NODD signal line

(1 trip detection logic)

Wire harness or connector
Inverter with converter assembly

Does not come on

Master Warning Light:

Comes on

P0A1114

DC/DC Converter Enable Circuit Short to Ground or Open

Open or short to ground detected in DC/DC converter NODD signal line

(1 trip detection logic)

Wire harness or connector
Inverter with converter assembly

Does not come on

Master Warning Light:

Comes on

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.
With power switch on (IG) and wait for 10 seconds or more.
Enter the following menus: Powertrain / Motor Generator / 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 or N/A, perform driving pattern again.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION:

Before the following operations are conducted, take precautions to prevent electric shock by turning the power switch off, wearing insulated gloves, and removing the service plug grip from HV battery.
- Inspecting the high-voltage system
- Disconnecting the low voltage connector of the inverter with converter assembly
- Disconnecting the low voltage connector of the HV battery
To prevent electric shock, make sure to remove the service plug grip to cut off the high voltage circuit before servicing the vehicle.
After removing the service plug grip from the HV battery, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.
After removing the service plug grip, wait for at least 10 minutes before touching any of the high-voltage connectors or terminals. After waiting for 10 minutes, check the voltage at the terminals in the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work.
Click here

HINT:

Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

*a

Without waiting for 10 minutes

NOTICE:

After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.

HINT:

If the NODD signal line is open, DC/DC converter control will be prohibited and the auxiliary battery voltage will be approximately 12 V or less.

Click here

PROCEDURE

1.	CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY CONNECTOR)

Click here

Result	Proceed to
OK	A
NG (The connector is not connected securely.)	B
NG (The terminals are not making secure contact or are deformed, or water or foreign matter exists in the connector.)	C

CONNECT SECURELY

REPAIR OR REPLACE HARNESS OR CONNECTOR

2.	CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - IGCT RELAY)

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Disconnect the A42 inverter with converter assembly connector.

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

Instrument Panel Relay Block

IGCT Relay

Front view of wire harness connector

(to Inverter with Converter Assembly)

Standard Resistance:

Tester Connection	Condition	Specified Condition
A42-12 (IGCT) - 5 (IGCT relay)	Power switch off	Below 1 Ω

(e) Install the IGCT relay.

(f) Reconnect the A42 inverter with converter assembly connector.

REPLACE INVERTER WITH CONVERTER ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR

Drive Motor "A" Inverter Actuator Stuck Open (P0A7872)

DTC SUMMARY

MALFUNCTION DESCRIPTION

This DTC is stored when the motor generator control system is malfunctioning and current does not flow as commanded. The cause of this malfunction may be one of the following:

Internal inverter malfunction

Inverter with converter assembly internal circuit malfunction

Inverter low-voltage circuit malfunction

The connectors are not connected properly

DESCRIPTION

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Warning Indicate
P0A7872	Drive Motor "A" Inverter Actuator Stuck Open	Malfunction is detected when offset component occurs in current flowing through motor with one phase open malfunction (1 trip detection logic)	Inverter with converter assembly Wire harness or connector	Comes on	Master Warning Light: Comes on

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

P0A7872

Drive Motor "A" Inverter Actuator Stuck Open

Malfunction is detected when offset component occurs in current flowing through motor with one phase open malfunction

(1 trip detection logic)

Inverter with converter assembly
Wire harness or connector

Comes on

Master Warning Light:

Comes on

MONITOR DESCRIPTION

The motor generator control ECU monitors the motor circuit. If the motor generator control ECU detects a malfunction of the motor (MG2), the ECU will illuminate the MIL and store a DTC.

MONITOR STRATEGY

Related DTCs	P0A78 (INF:P0A7872) : Drive Motor "A" Inverter Performance
Required sensors/components	Motor inverter
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

Motor generator control ECU

DTC P0A78 (INF P0A7872) is not detected

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
When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" 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). [*1]
Move the shift lever to D, and then accelerate until the vehicle speed is 40 km/h (25 mph) and the accelerator position is approximately 30%. [*2]
HINT:

[*1] to [*2]: Normal judgment procedure.

The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.
Enter the following menus: Powertrain / Motor Generator / 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 or N/A, perform the normal judgment procedure again.

WIRING DIAGRAM

Refer to the wiring diagram for the Motor High-voltage Circuit.

Click here

CAUTION / NOTICE / HINT

CAUTION:

Before the following operations are conducted, take precautions to prevent electric shock by turning the power switch off, wearing insulated gloves, and removing the service plug grip from HV battery.
- Inspecting the high-voltage system
- Disconnecting the low voltage connector of the inverter with converter assembly
- Disconnecting the low voltage connector of the HV battery
To prevent electric shock, make sure to remove the service plug grip to cut off the high voltage circuit before servicing the vehicle.
After removing the service plug grip from the HV battery, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.
After removing the service plug grip, wait for at least 10 minutes before touching any of the high-voltage connectors or terminals. After waiting for 10 minutes, check the voltage at the terminals in the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work.
Click here

*a

Without waiting for 10 minutes

HINT:

Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

NOTICE:

Click here

PROCEDURE

1.	CHECK DTC OUTPUT

(a) Connect the Techstream to the DLC3.

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

(d) Check for DTCs.

Powertrain > Hybrid Control > Trouble Codes Powertrain > Motor Generator > Trouble Codes

Result	Proceed to
P0A7872 only is output, or DTCs except the ones in the table below are also output.	A
DTCs of hybrid control system in the tables below are output.	B
DTCs of motor generator control system in the tables below are output.	C

Table 1

Malfunction Content	System	Relevant DTC
Insulation Malfunction	Hybrid control system	P1C7C49	Hybrid/EV Battery Voltage System Isolation (A/C Area) Internal Electronic Failure
		P1C7D49	Hybrid/EV Battery Voltage System Isolation (Hybrid/EV Battery Area) Internal Electronic Failure
		P1C7E49	Hybrid/EV Battery Voltage System Isolation (Transaxle Area) Internal Electronic Failure
		P1C7F49	Hybrid/EV Battery Voltage System Isolation (Direct Current Area) Internal Electronic Failure
System Main Relay or High Voltage Circuit Malfunction	Hybrid control system	P0AD911	Hybrid/EV Battery Positive Contactor Circuit Short to Ground
		P0AD915	Hybrid/EV Battery Positive Contactor Circuit Short to Auxiliary Battery or Open
		P0ADD11	Hybrid/EV Battery Negative Contactor Circuit Short to Ground
		P0ADD15	Hybrid/EV Battery Negative Contactor Circuit Short to Auxiliary Battery or Open
		P1C8449	High Voltage Power Resource Circuit Short during Ready ON

Table 2

Malfunction Content	System	Relevant DTC
Microcomputer malfunction	Motor generator control system	P0A1A47	Generator Control Module Watchdog / Safety μC Failure
		P0A1A49	Generator Control Module Internal Electronic Failure
		P0A1B1F	Generator Control Module Circuit Intermittent
		P1C2A1C	Generator A/D Converter Circuit Circuit Voltage Out of Range
		P1C2A49	Generator A/D Converter Circuit Internal Electronic Failure
		P1C2B1C	Drive Motor "A" Control Module A/D Converter Circuit Voltage Out of Range
		P1C2B49	Drive Motor "A" Control Module A/D Converter Circuit Internal Electronic Failure
		P313383	Communication Error from Generator to Drive Motor "A" Value of Signal Protection Calculation Incorrect
		P313386	Communication Error from Generator to Drive Motor "A" Signal Invalid
		P313387	Communication Error from Generator to Drive Motor "A" Missing Message
		P313483	Communication Error from Drive Motor "A" to Generator Value of Signal Protection Calculation Incorrect
		P313486	Communication Error from Drive Motor "A" to Generator Signal Invalid
		P313487	Communication Error from Drive Motor "A" to Generator Missing Message
	Hybrid control system	P0A1B49	Drive Motor "A" Control Module Internal Electronic Failure
Power source circuit malfunction	Motor generator control system	P06B01C	Generator Control Module Position Sensor REF Power Source Circuit Voltage Out of Range
Power source circuit malfunction	Motor generator control system	P06D61C	Generator Control Module Offset Power Circuit Voltage Out of Range
Sensor and actuator circuit malfunction	Motor generator control system	P0A3F16	Drive Motor "A" Position Sensor Circuit Voltage Below Threshold
		P0A3F21	Drive Motor "A" Position Sensor Signal Amplitude < Minimum
		P0A3F22	Drive Motor "A" Position Sensor Signal Amplitude > Maximum
		P0A4B16	Generator Position Sensor Circuit Voltage Below Threshold
		P0A4B21	Generator Position Sensor Signal Amplitude < Minimum
		P0A4B22	Generator Position Sensor Signal Amplitude > Maximum
		P0A6012	Drive Motor "A" Phase V Current (High Resolution) Circuit Short to Battery
		P0A6014	Drive Motor "A" Phase V Current (High Resolution) Circuit Short to Ground or Open
		P0A601C	Drive Motor "A" Phase V Current (High Resolution) Circuit Voltage Out of Range
		P0A6312	Drive Motor "A" Phase W Current (High Resolution) Circuit Short to Battery
		P0A6314	Drive Motor "A" Phase W Current (High Resolution) Circuit Short to Ground or Open
		P0A631C	Drive Motor "A" Phase W Current (High Resolution) Circuit Voltage Out of Range
		P0BE512	Drive Motor "A" Phase U Current Sensor Circuit Short to Battery
		P0BE514	Drive Motor "A" Phase U Current Sensor Circuit Short to Ground or Open
		P0BE528	Drive Motor "A" Phase U Current Sensor Signal Bias Level Out of Range / Zero Adjustment Failure
		P0BE912	Drive Motor "A" Phase V Current Sensor Circuit Short to Battery
		P0BE914	Drive Motor "A" Phase V Current Sensor Circuit Short to Ground or Open
		P0BE928	Drive Motor "A" Phase V Current Sensor Signal Bias Level Out of Range / Zero Adjustment Failure
		P0BED12	Drive Motor "A" Phase W Current Sensor Circuit Short to Battery
		P0BED14	Drive Motor "A" Phase W Current Sensor Circuit Short to Ground or Open
		P0BED28	Drive Motor "A" Phase W Current Sensor Signal Bias Level Out of Range / Zero Adjustment Failure
		P0BFD62	Drive Motor "A" Phase U-V-W Current Sensor Signal Compare Failure
		P0C5013	Drive Motor "A" Position Sensor Circuit "A" Circuit Open
		P0C5016	Drive Motor "A" Position Sensor Circuit "A" Circuit Voltage Below Threshold
		P0C5017	Drive Motor "A" Position Sensor Circuit "A" Circuit Voltage Above Threshold
		P0C5A13	Drive Motor "A" Position Sensor Circuit "B" Circuit Open
		P0C5A16	Drive Motor "A" Position Sensor Circuit "B" Circuit Voltage Below Threshold
		P0C5A17	Drive Motor "A" Position Sensor Circuit "B" Circuit Voltage Above Threshold
		P0C6413	Generator Position Sensor Circuit "A" Circuit Open
		P0C6416	Generator Position Sensor Circuit "A" Circuit Voltage Below Threshold
		P0C6417	Generator Position Sensor Circuit "A" Circuit Voltage Above Threshold
		P0C6913	Generator Position Sensor Circuit "B" Circuit Open
		P0C6916	Generator Position Sensor Circuit "B" Circuit Voltage Below Threshold
		P0C6917	Generator Position Sensor Circuit "B" Circuit Voltage Above Threshold
		P0D2D16	Drive Motor "A" Inverter Voltage Sensor (VH) Circuit Voltage Below Threshold
		P0D2D17	Drive Motor "A" Inverter Voltage Sensor (VH) Circuit Voltage Above Threshold
		P0DFA62	Generator Phase U-V-W Current Sensor Signal Compare Failure
		P0E0012	Generator Phase U Current Sensor Circuit Short to Battery
		P0E0014	Generator Phase U Current Sensor Circuit Short to Ground or Open
		P0E0028	Generator Phase U Current Sensor Signal Bias Level Out of Range / Zero Adjustment Failure
		P0E0412	Generator Phase V Current Sensor Circuit Short to Battery
		P0E0414	Generator Phase V Current Sensor Circuit Short to Ground or Open
		P0E0428	Generator Phase V Current Sensor Signal Bias Level Out of Range / Zero Adjustment Failure
		P0E0812	Generator Phase W Current Sensor Circuit Short to Battery
		P0E0814	Generator Phase W Current Sensor Circuit Short to Ground or Open
		P0E0828	Generator Phase W Current Sensor Signal Bias Level Out of Range / Zero Adjustment Failure
		P0E3116	DC/DC Converter Voltage Sensor "A" (VL) Circuit Voltage Below Threshold
		P0E3117	DC/DC Converter Voltage Sensor "A" (VL) Circuit Voltage Above Threshold
		P0E5111	DC/DC Converter Current Sensor Circuit Short to Ground
		P0E5115	DC/DC Converter Current Sensor Circuit Short to Battery or Open
		P0E512A	DC/DC Converter Current Sensor Signal Stuck In Range
		P1CAC49	Generator Position Sensor Internal Electronic Failure
		P1CAD49	Drive Motor "A" Position Sensor Internal Electronic Failure
		P1CAF38	Generator Position Sensor REF Signal Cycle Malfunction Signal Frequency Incorrect
		P1CB038	Drive Motor "A" Position Sensor REF Signal Frequency Incorrect
	Hybrid control system	P0C7600	Hybrid/EV Battery System Discharge Time Too Long
		P0D2D1C	Drive Motor "A" Inverter Voltage Sensor Voltage Out of Range
		P0E311C	Boosting Converter Voltage Sensor "A" Voltage Out of Range
		P1C2D62	Hybrid/EV Battery "A" Voltage Sensor/Boosting Converter Voltage Sensor "A" Signal Compare Failure

HINT:

P0A7872 may be output as a result of the malfunctions indicated by the DTCs above.
1. The chart above is listed in inspection order of priority.
2. Check DTCs that are output at the same time by following the listed order. (The main cause of the malfunction can be determined without performing unnecessary inspections.)

(e) Turn the power switch off.

GO TO DTC CHART (HYBRID CONTROL SYSTEM)

GO TO DTC CHART (MOTOR GENERATOR CONTROL SYSTEM)

2.	CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY CONNECTOR)

Click here

Result	Proceed to
OK	A
NG (The connector is not connected securely.)	B
NG (The terminals are not making secure contact or are deformed, or water or foreign matter exists in the connector.)	C

CONNECT SECURELY

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.	CHECK MOTOR HIGH-VOLTAGE CIRCUIT

Click here

HINT:

If the "Motor High-voltage Circuit" inspection results are normal, perform the next step.

REPLACE INVERTER WITH CONVERTER ASSEMBLY

Drive Motor "A" Inverter Actuator Stuck Closed (P0A7873)

DTC SUMMARY

MALFUNCTION DESCRIPTION

This DTC is stored when a short is detected in the inverter with converter assembly (motor inverter) or the hybrid vehicle transaxle assembly (motor (MG2)). The cause of this malfunction may be one of the following:

Internal inverter malfunction

Motor inverter internal circuit malfunction

Hybrid vehicle transaxle assembly (motor (MG2)) malfunction

Open or short circuit
Iron particles or damage from foreign objects

DESCRIPTION

For a description of the inverter.

Click here

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Warning Indicate
P0A7873	Drive Motor "A" Inverter Actuator Stuck Closed	Current flow to any phase of the motor (MG2) exceeds the threshold after the motor inverter is shut down due to a DTC indicating a motor inverter malfunction (overheating, overcurrent or circuit malfunction) being stored. (1 trip detection logic)	Inverter with converter assembly Motor cable Hybrid vehicle transaxle assembly	Comes on	Master Warning Light: Comes on

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

P0A7873

Drive Motor "A" Inverter Actuator Stuck Closed

Current flow to any phase of the motor (MG2) exceeds the threshold after the motor inverter is shut down due to a DTC indicating a motor inverter malfunction (overheating, overcurrent or circuit malfunction) being stored.

(1 trip detection logic)

Inverter with converter assembly
Motor cable
Hybrid vehicle transaxle assembly

Comes on

Master Warning Light:

Comes on

MONITOR DESCRIPTION

The motor generator control ECU monitors the motor inverter electric current. If the current exceeds the threshold for a specified period of time, the motor generator control ECU will illuminate the MIL and set a DTC.

MONITOR STRATEGY

Related DTCs	P0A78 (INF P0A7873): MFIV detection (Short circuit malfunction)
Required sensors/components	Motor inverter
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

Motor generator control ECU

DTC P0A78 (INF P0A7873) is not detected

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
When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" 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.
With power switch on (IG) and wait for 5 seconds or more. [*1]
Turn the power switch on (READY) and wait for 5 seconds or more. [*2]
Drive the vehicle for approximately 10 minutes mainly using the engine. During the road test, check the Data List item "Motor Inverter Temperature" to prevent the motor inverter from overheating. [*3]
NOTICE:

As the state of charge of the HV battery may be low after driving in fail-safe mode, it will automatically be charged for 5 to 10 minutes with power switch on (READY) after repairs have been performed.

HINT:

[*1] to [*3]: Normal judgment procedure.

The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.
Enter the following menus: Powertrain / Motor Generator / 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 or N/A, perform the normal judgment procedure again.

WIRING DIAGRAM

Refer to the wiring diagram for the Motor High-voltage Circuit.

Click here

CAUTION / NOTICE / HINT

CAUTION:

Before the following operations are conducted, take precautions to prevent electric shock by turning the power switch off, wearing insulated gloves, and removing the service plug grip from HV battery.
- Inspecting the high-voltage system
- Disconnecting the low voltage connector of the inverter with converter assembly
- Disconnecting the low voltage connector of the HV battery
To prevent electric shock, make sure to remove the service plug grip to cut off the high voltage circuit before servicing the vehicle.
After removing the service plug grip from the HV battery, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.
After removing the service plug grip, wait for at least 10 minutes before touching any of the high-voltage connectors or terminals. After waiting for 10 minutes, check the voltage at the terminals in the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work.
Click here

HINT:

Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

*a

Without waiting for 10 minutes

NOTICE:

After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.
Click here
DTC P0A7873 is stored after DTCs P0A789E and/or P1C5D19 are stored. After troubleshooting and repairing the malfunction which caused DTC P0A7873 to be stored, be sure to troubleshoot the other DTCs.
Depending on the conditions in which the vehicle is being operated when a short circuit occurs in the inverter with converter assembly, the hybrid vehicle transaxle assembly may be affected. As this DTC is stored if a short circuit occurs in the inverter with converter assembly, it is necessary to perform a road test to check the hybrid vehicle transaxle assembly. If problems are found, replace the malfunctioning parts.
After completing the repair, including the repair of previously output DTCs, drive the vehicle at a speed of approximately 40 km/h (25 mph) for 1 minute and check that DTC P0A9000 is not output. If DTC P0A9000 is output, replace the hybrid vehicle transaxle assembly.

PROCEDURE

1.	CHECK DTC OUTPUT (HYBRID CONTROL)

(a) Connect the Techstream to the DLC3.

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

(d) Check for DTCs.

Powertrain > Hybrid Control > Trouble Codes

Result	Proceed to
P0A7873 only is output, or DTCs except the ones in the table below are also output.	A
Any of the following DTCs are also output.	B

Malfunction Content	Relevant DTC
Insulation Malfunction	P1C7C49	Hybrid/EV Battery Voltage System Isolation (A/C Area) Internal Electronic Failure
	P1C7D49	Hybrid/EV Battery Voltage System (Hybrid/EV Battery Area) Insulation Resistance Decreased
	P1C7E49	Hybrid/EV Battery Voltage System Isolation (Transaxle Area) Internal Electronic Failure
	P1C7F49	Hybrid/EV Battery Voltage System Isolation (Direct Current Area) Internal Electronic Failure

HINT:

P0A7873 may be output as a result of the malfunctions indicated by the DTCs above.
1. The chart above is listed in inspection order of priority.
2. Check DTCs that are output at the same time by following the listed order. (The main cause of the malfunction can be determined without performing unnecessary inspections.)

(e) Turn the power switch off.

GO TO DTC CHART (HYBRID CONTROL SYSTEM)

2.	CHECK HYBRID VEHICLE TRANSAXLE ASSEMBLY (MOTOR (MG2))

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Disconnect the motor cable from the hybrid vehicle transaxle assembly.

(1) Using a milliohmmeter, measure the resistance according to the value(s) in the table below.

HINT:

If the motor (MG2) temperature is high, the resistance will vary greatly from the specification. Therefore, measure the resistance at least 8 hours after the vehicle has been stopped.

Standard Resistance:

Tester Connection	Condition	Specified Condition
W1-1 (W) - W1-2 (U)	Power switch off	61.4 to 68.0 mΩ
W1-2 (U) - W1-3 (V)	Power switch off	61.4 to 68.0 mΩ
W1-1 (W) - W1-3 (V)	Power switch off	61.6 to 68.2 mΩ

HINT:

To correct the variation of the measured resistance due to temperature, use the following formula to calculate the resistance at 20°C (68° F).

R20 = Rt / {1 + 0.00393 X (T - 20)}

The calculation is based on the following:

R20: Resistance at 20°C (68° F) (mΩ)
Rt: Measured resistance (mΩ)
T: Temperature when the resistance is measured (° C)

(d) Using a megohmmeter set to 500 V, measure the resistance according to the value(s) in the table below.

NOTICE:

Be sure to set the megohmmeter to 500 V when performing this test. Using a setting higher than 500 V can result in damage to the component being inspected.

Standard Resistance:

Tester Connection	Condition	Specified Condition
W1-1 (W) - Body ground and shield ground	Power switch off	100 MΩ or higher
W1-2 (U) - Body ground and shield ground	Power switch off	100 MΩ or higher
W1-3 (V) - Body ground and shield ground	Power switch off	100 MΩ or higher

(e) Connect the motor cable.

GO TO STEP 5

3.	REPLACE INVERTER WITH CONVERTER ASSEMBLY

Click here

4.	REPLACE MOTOR CABLE

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GO TO STEP 8

5.	REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY

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6.	REPLACE INVERTER WITH CONVERTER ASSEMBLY

Click here

7.	REPLACE MOTOR CABLE

Click here

8.	CHECK DTC OUTPUT (HYBRID CONTROL)

(a) Check the other DTCs that were output together with DTC P0A7873.

Powertrain > Motor Generator > Trouble Codes

Relevant DTC
P0A789E	Drive Motor "A" Inverter Stuck On
P1C5D19	Drive Motor "A" Inverter Circuit Current Above Threshold

NOTICE:

DTC P0A7873 is stored after DTCs P0A789E and/or P1C5D19 are stored. After troubleshooting and repairing the malfunction which caused P0A7873 to be stored, be sure to troubleshoot the other DTCs.

GO TO DTC CHART (MOTOR GENERATOR CONTROL SYSTEM)

DC/DC Converter Stuck On (P0A949E,P0D3319)

Drive Motor "A" Performance (P0A9000)

See More:

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