HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with P610): Motor Resolver Circuit; 2021 - 2022 MY Corolla Corolla HV [04/2020

Last Modified: 05-13-2024	6.11:8.1.0	Doc ID: RM100000001N40I
Model Year Start: 2021	Model: Corolla	Prod Date Range: [04/2020 - 09/2022]
Title: HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with P610): Motor Resolver Circuit; 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]

Motor Resolver Circuit

DESCRIPTION

The cause of this malfunction may be the motor resolver.

Check the motor resolver internal resistance and the connection condition from the inverter to the resolver.

Related Parts Check

Area	Inspection
Wire harness and connector between the inverter and motor resolver	Check for short circuit between wire harness and +B side.
Resolver, wire harness, connector	Check the internal resistance of resolver (including wire harness), body ground resistance, and connector connection condition.
Resolver	Check for open or short circuit of the resolver.

SYSTEM DESCRIPTION

A resolver is a sensor that is used to detect the position of the magnetic poles of the rotor of a motor. Knowing the position of the poles is indispensable for ensuring precise control of the motor (MG2).

Each resolver contains a stator that has an excitation coil and 2 detection coils (S, C). The gap between the stator and rotor changes as the rotor turns because the rotor is oval shaped. An alternating current with a predetermined frequency flows through the excitation coil, and detection coils S and C output alternating currents in accordance with the sensor rotor position.

The MG ECU, which is built into the inverter with converter assembly, detects the absolute position of the rotor according to the phases of detection coils S and C and the heights of their waveforms. Furthermore, the CPU calculates the amount of change in the position within a predetermined length of time, in order to use the resolver as a revolution speed sensor.

The MG ECU monitors signals output from the motor resolver and detects malfunctions.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

This diagnostic procedure is referenced to in the diagnostic procedure of several DTCs.

If the result of this diagnostic procedure is normal, proceed as directed in the procedure for the DTC.

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.

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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.

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HINT:

If the problem symptom cannot be reproduced, performing a road test on a road on which the vehicle tends to vibrate will make it easier to reproduce the symptom.
If the resolver is malfunctioning, the vehicle may not drive smoothly.
When inspecting the connectors, if it is difficult to judge if a connector was disconnected, deformed or improperly secured, disconnect and reconnect the connector and then check for DTCs again. Check if the same DTC is output. If the same DTC is not output, improper connection of connectors is suspected.
As a malfunction detection threshold may be exceeded when performing the vibration or heat connector inspections, make sure to perform the following inspection to check that the DTC was not stored due to the malfunction of a part.

PROCEDURE

1.	CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - MOTOR RESOLVER)

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 C90 inverter with converter assembly connector.

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

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
C90-5 (MRF) - Body ground	Power switch on (IG)	Below 1 V
C90-6 (MRFG) - Body ground	Power switch on (IG)	Below 1 V
C90-1 (MSN) - Body ground	Power switch on (IG)	Below 1 V
C90-2 (MSNG) - Body ground	Power switch on (IG)	Below 1 V
C90-4 (MCS) - Body ground	Power switch on (IG)	Below 1 V
C90-3 (MCSG) - Body ground	Power switch on (IG)	Below 1 V

NOTICE:

Turning the power switch on (IG) with the inverter with converter assembly disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

*a	Front view of wire harness connector (to Inverter with Converter Assembly)

(f) Turn the power switch off.

(g) Disconnect the cable from the negative (-) auxiliary battery terminal and wait for 2 minutes or more.

(h) Reconnect the C90 inverter with converter assembly connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR

2.	CHECK MOTOR RESOLVER

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 C90 inverter with converter assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
C90-5 (MRF) - C90-6 (MRFG)	Power switch off	8.9 to 14.9 Ω
C90-1 (MSN) - C90-2 (MSNG)	Power switch off	16.2 to 28.1 Ω
C90-4 (MCS) - C90-3 (MCSG)	Power switch off	18.2 to 30.1 Ω

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 (°F).)

Standard Resistance (Check for Short):

Tester Connection	Condition	Specified Condition
C90-5 (MRF) or C90-6 (MRFG) - Body ground and other terminals	Power switch off	1 MΩ or higher
C90-1 (MSN) or C90-2 (MSNG) - Body ground and other terminals	Power switch off	1 MΩ or higher
C90-4 (MCS) or C90-3 (MCSG) - Body ground and other terminals	Power switch off	1 MΩ or higher

*a	Front view of wire harness connector (to Inverter with Converter Assembly)

(d) Reconnect the C90 inverter with converter assembly connector.

MOTOR RESOLVER CIRCUIT NORMAL (PERFORM NEXT STEP FOR REFERENCED DTC)

3.	CHECK CONNECTOR CONNECTION CONDITION (RESOLVER CONNECTOR)

(a) Check the connection condition of the resolver connector and the contact pressure of each terminal. Check the terminals for deformation, and check the connector for water ingress and foreign matter.

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OK:

- The connector is connected securely.

- The terminals are not deformed and are connected securely.

- No water or foreign matter in the connector.

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

4.	INSPECT HYBRID VEHICLE TRANSAXLE ASSEMBLY (MOTOR RESOLVER)

(a) Disconnect the C92 resolver connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
C92-6 (MRF) - C92-9 (MRFG)	Power switch off	8.8 to 14.8 Ω
C92-4 (MSN) - C92-5 (MSNG)	Power switch off	16.2 to 28.0 Ω
C92-10 (MCS) - C92-14 (MCSG)	Power switch off	18.1 to 30.0 Ω

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 (°F).)

Standard Resistance (Check for Short):

Tester Connection	Condition	Specified Condition
C92-6 (MRF) - Body ground and other terminals (except C92-9 (MRFG))	Power switch off	1 MΩ or higher
C92-9 (MRFG) - Body ground and other terminals (except C92-6 (MRF))	Power switch off	1 MΩ or higher
C92-4 (MSN) - Body ground and other terminals (except C92-5 (MSNG))	Power switch off	1 MΩ or higher
C92-5 (MSNG) - Body ground and other terminals (except C92-4 (MSN))	Power switch off	1 MΩ or higher
C92-10 (MCS) - Body ground and other terminals (except C92-14 (MCSG))	Power switch off	1 MΩ or higher
C92-14 (MCSG) - Body ground and other terminals (except C92-10 (MCS))	Power switch off	1 MΩ or higher

*a	Component without harness connected (Motor Resolver (Hybrid Vehicle Transaxle Assembly))

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY