Last Modified: 05-13-2024 |
6.11:8.1.0 |
Doc ID: RM100000001N40N |
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): Inverter Low-voltage Circuit; 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022] |
Inverter Low-voltage Circuit
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DESCRIPTION
The cause of the malfunction may be the low-voltage circuit.
Check whether there is an open circuit in the inverter +B low-voltage power source system or a problem in the communication between the hybrid vehicle control ECU and inverter.
Related Parts Check
Area
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Inspection
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Inverter +B low-voltage power source system check
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Check for inverter overcurrent malfunction.
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Communication malfunction between hybrid vehicle control ECU and MG-ECU inside inverter with converter assembly
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Check for inverter overcurrent malfunction due to communication malfunction.
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Check for short to ground in inverter +B low-voltage power source system
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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:
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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.
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Inspecting the high-voltage system
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Disconnecting the low voltage connector of the inverter with converter assembly
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Disconnecting the low voltage connector of the HV battery
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To prevent electric shock, make sure to remove the service plug grip to cut off the high voltage circuit before servicing the vehicle.
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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.
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
PROCEDURE
(a) Remove the PCU FR fuse from the No. 1 engine room relay block and No. 1 junction block assembly.
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*1
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No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
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*2
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PCU FR Fuse
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(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
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Condition
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Specified Condition
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PCU FR fuse
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Always
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Below 1 Ω
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(c) Reinstall the PCU FR fuse.
OK
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2.
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CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY POWER SOURCE CIRCUIT)
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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.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
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Condition
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Specified Condition
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C89-24 (GND1) - Body ground
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Power switch off
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Below 1 Ω
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C89-23 (GND2) - Body ground
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Power switch off
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Below 1 Ω
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*a
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Front view of wire harness connector
(to Inverter with Converter Assembly)
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(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
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Condition
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Specified Condition
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C89-6 (+B) - Body ground
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Power switch on (IG)
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Same as auxiliary battery voltage
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C89-5 (+B2) - Body ground
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Power switch on (IG)
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Same as auxiliary battery voltage
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NOTICE:
Turning the power switch on (IG) with the inverter with converter assembly connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.
(g) Turn the power switch off.
(h) Disconnect the cable from the negative (-) auxiliary battery terminal and wait for 2 minutes or more.
(i) Reconnect the C89 inverter with converter assembly connector.
NG |
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REPAIR OR REPLACE POWER SOURCE CIRCUIT
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OK
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3.
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CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - INVERTER WITH CONVERTER ASSEMBLY)
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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.
(c) Disconnect the A57 hybrid vehicle control ECU connector.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
Tester Connection
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Condition
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Specified Condition
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C89-20 (HMCH) - A57-4 (HMCH)
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Power switch off
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Below 1 Ω
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C89-19 (HMCL) - A57-14 (HMCL)
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Power switch off
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Below 1 Ω
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Standard Resistance (Check for Short):
Tester Connection
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Condition
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Specified Condition
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C89-20 (HMCH) or A57-4 (HMCH) - Body ground and other terminals
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Power switch off
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10 kΩ or higher
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C89-19 (HMCL) or A57-14 (HMCL) - Body ground and other terminals
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Power switch off
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10 kΩ or higher
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*a
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Front view of wire harness connector
(to Inverter with Converter Assembly)
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*b
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Front view of wire harness connector
(to Hybrid Vehicle Control ECU)
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(e) Connect the cable to the negative (-) auxiliary battery terminal.
(f) Turn the power switch on (IG).
(g) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection
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Condition
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Specified Condition
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C89-20 (HMCH) or A57-4 (HMCH) - Body ground and other terminals
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Power switch on (IG)
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Below 1 V
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C89-19 (HMCL) or A57-14 (HMCL) - Body ground and other terminals
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Power switch on (IG)
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Below 1 V
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NOTICE:
Turning the power switch on (IG) with the hybrid vehicle control ECU and inverter with converter assembly connectors disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.
(h) Turn the power switch off.
(i) Disconnect the cable from the negative (-) auxiliary battery terminal and wait for 2 minutes or more.
(j) Reconnect the A57 hybrid vehicle control ECU connector.
(k) Reconnect the C89 inverter with converter assembly connector.
NG |
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REPAIR OR REPLACE HARNESS OR CONNECTOR
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OK
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4.
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CHECK HYBRID VEHICLE CONTROL ECU
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(a) Disconnect the A57 hybrid vehicle control ECU connector.
(b) Measure the resistance according to the value(s) in the table below.
*a
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Component without harness connected
(Hybrid Vehicle Control ECU)
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-
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-
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Standard Resistance:
Tester Connection
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Condition
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Specified Condition
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A57-4 (HMCH) - A57-14 (HMCL)
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Power switch off
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80 to 170 Ω
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(c) Reconnect the A57 hybrid vehicle control ECU connector.
OK |
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INVERTER LOW-VOLTAGE CIRCUIT NORMAL (PERFORM NEXT STEP FOR REFERENCED DTC)
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5.
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CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - PCU FR FUSE)
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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.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
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Condition
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Specified Condition
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C89-6 (+B) - Body ground
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Power switch off
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10 kΩ or higher
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C89-5 (+B2) - Body ground
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Power switch off
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10 kΩ or higher
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*a
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Front view of wire harness connector
(to Inverter with Converter Assembly)
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(d) Reconnect the C89 inverter with converter assembly connector.
OK
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6.
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REFER TO REPLACE INVERTER WITH CONVERTER ASSEMBLY PARTS
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Click here
NEXT |
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REPLACE FUSE (PCU FR)
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7.
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REPAIR OR REPLACE HARNESS OR CONNECTOR
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NEXT |
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REPLACE FUSE (PCU FR)
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