HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): Shut Down Signal Circuit; 2020 - 2022 MY Corolla Corolla HV [01/2019

Last Modified: 05-13-2024	6.11:8.1.0	Doc ID: RM100000001GCMP
Model Year Start: 2020	Model: Corolla	Prod Date Range: [01/2019 - 09/2022]
Title: HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): Shut Down Signal Circuit; 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]

Shut Down Signal Circuit

DESCRIPTION

The cause of the malfunction may be a shutdown signal.

Check whether there is a shutdown signal +B short circuit.

Related Parts Check

Area	Inspection
HSDN terminal	Check that the HSDN terminal voltage decreases to check for an open or short circuit while READY off (IG ON).
Hybrid vehicle control ECU, inverter, wire harness	Check for open or short circuit in hybrid vehicle control ECU, inverter and wire harness.

SYSTEM DESCRIPTION

Power supply to the motor is cut off due to a shutdown signal sent from the hybrid vehicle control ECU to the motor generator control ECU (MG ECU).

WIRING DIAGRAM

Refer to the wiring diagram for the ECU power source circuit.

Click here

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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PROCEDURE

1.	CHECK HYBRID VEHICLE CONTROL ECU

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

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

Component with harness connected

(Hybrid Vehicle Control ECU)

Standard Voltage:

Tester Connection	Condition	Specified Condition
A57-6 (HSDN) - I3-3 (E1)	Power switch on (IG)	Below 4.5 V

SHUTDOWN SIGNAL CIRCUIT NORMAL (PERFORM NEXT STEP FOR REFERENCED DTC)

2.	CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - INVERTER WITH CONVERTER ASSEMBLY)

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 C89 inverter with converter assembly connector.

(d) Connect the cable to the negative (-) auxiliary battery terminal.

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

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
C89-22 (HSDN) or A57-6 (HSDN) - Body ground	Power switch on (IG)	Below 1 V

NOTICE:

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

Front view of wire harness connector

(to Inverter with Converter Assembly)

Front view of wire harness connector

(to Hybrid Vehicle Control ECU)

(g) Turn the power switch off.

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
C89-22 (HSDN) - C89-6 (+B)	Power switch off	10 kΩ or higher
C89-22 (HSDN) - C89-5 (+B2)	Power switch off	10 kΩ or higher
A57-6 (HSDN) - A57-11 (+B1)	Power switch off	10 kΩ or higher
A57-6 (HSDN) - A57-5 (MREL)	Power switch off	10 kΩ or higher

(j) Reconnect the A57 hybrid vehicle control ECU connector.

(k) Reconnect the C89 inverter with converter assembly connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.	CHECK INVERTER WITH CONVERTER ASSEMBLY

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 C89 inverter with converter assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
C89-22 (HSDN) - C89-6 (+B)	Power switch off	10 kΩ or higher
C89-22 (HSDN) - C89-5 (+B2)	Power switch off	10 kΩ or higher

*a	Component without harness connected (Inverter with Converter Assembly)

(d) Reconnect the C89 inverter with converter assembly connector.

REPLACE HYBRID VEHICLE CONTROL ECU

REFER TO REPLACE INVERTER WITH CONVERTER ASSEMBLY PARTS