Toyota Corolla Cross: Inverter Low-voltage Circuit
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 | Inspection |
|---|---|
|
Inverter +B low-voltage power source system check |
Check for inverter overcurrent malfunction. |
|
Communication malfunction between hybrid vehicle control ECU and MG-ECU inside inverter with converter assembly |
Check for inverter overcurrent malfunction due to communication malfunction. |
|
Check for short to ground in inverter +B low-voltage power source system |
- |
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:
Refer to the precautions before inspecting high voltage circuit.
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NOTICE:
- After the ignition switch is turned off, there may be a waiting time before disconnecting the negative (-) auxiliary battery terminal.
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- When disconnecting and reconnecting the auxiliary battery
HINT:
When disconnecting and reconnecting the auxiliary battery, there is an automatic learning function that completes learning when the respective system is used.
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PROCEDURE
|
1. | CHECK FUSE (PCU NO. 1) |
(a) Remove the PCU NO. 1 fuse from the No. 1 engine room relay block and No. 1 junction block assembly.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
PCU NO. 1 fuse | Always |
Below 1 Ω |
(c) Install the PCU NO. 1 fuse.
| NG | .gif) | GO TO STEP 5 |
|
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|
2. | CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY POWER SOURCE CIRCUIT) |
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 ignition switch to ON (READY), unless instructed by the repair manual because this may cause a malfunction.
(b) Disconnect the inverter with converter assembly connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
A187-4 (GND1) - Body ground |
Ignition switch off |
Below 1 Ω |
|
A187-12 (GND2) - Body ground |
Ignition switch off |
Below 1 Ω |
(d) Connect the cable to the negative (-) auxiliary battery terminal.
(e) Turn the ignition switch to ON.
(f) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
A187-1 (IGC1) - Body ground |
Ignition switch ON |
Same as auxiliary battery voltage |
|
A187-9 (IGC2) - Body ground |
Ignition switch ON |
Same as auxiliary battery voltage |
NOTICE:
Turning the ignition switch to ON with the inverter with converter assembly connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.
(g) Turn the ignition switch off.
(h) Disconnect the cable from the negative (-) auxiliary battery terminal and wait for 2 minutes or more.
(i) Reconnect the inverter with converter assembly connector.
| NG | | REPAIR OR REPLACE POWER SOURCE CIRCUIT |
|
|
3. | 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 ignition switch to ON (READY), unless instructed by the repair manual because this may cause a malfunction.
(b) Disconnect the inverter with converter assembly connector.
(c) Disconnect the 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 | Condition |
Specified Condition |
|---|---|---|
|
A187-29 (HMCH) - A192-2 (HMCH) |
Ignition switch off |
Below 1 Ω |
|
A187-30 (HMCL) - A192-1 (HMCL) |
Ignition switch off |
Below 1 Ω |
Standard Resistance (Check for Short):
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
A187-29 (HMCH) or A192-2 (HMCH) - Body ground and other terminals |
Ignition switch off |
10 kΩ or higher |
|
A187-30 (HMCL) or A192-1 (HMCL) - Body ground and other terminals |
Ignition switch off |
10 kΩ or higher |
(e) Connect the cable to the negative (-) auxiliary battery terminal.
(f) Turn the ignition switch to ON.
(g) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
A187-29 (HMCH) or A192-2 (HMCH) - Body ground and other terminals |
Ignition switch ON |
Below 1 V |
|
A187-30 (HMCL) or A192-1 (HMCL) - Body ground and other terminals |
Ignition switch ON |
Below 1 V |
NOTICE:
Turning the ignition switch to ON 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 ignition switch off.
(i) Disconnect the cable from the negative (-) auxiliary battery terminal and wait for 2 minutes or more.
(j) Reconnect the hybrid vehicle control ECU connector.
(k) Reconnect the inverter with converter assembly connector.
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
4. | CHECK HYBRID VEHICLE CONTROL ECU |
(a) Disconnect the hybrid vehicle control ECU connector.
(b) Measure the resistance according to the value(s) in the table below.
|
*a | Component without harness connected (Hybrid Vehicle Control ECU) |
- | - |
Standard Resistance:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
A192-1 (HMCL) - A192-2 (HMCH) |
Ignition switch off |
80 to 170 Ω |
(c) Reconnect the hybrid vehicle control ECU connector.
| OK | | INVERTER LOW-VOLTAGE CIRCUIT NORMAL (PERFORM NEXT STEP FOR REFERENCED DTC) |
| NG | | REPLACE HYBRID VEHICLE CONTROL ECU |
|
5. | CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - PCU FUSE) |
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 ignition switch to ON (READY), unless instructed by the repair manual because this may cause a malfunction.
(b) Disconnect the inverter with converter assembly connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
A187-1 (IGC1) - Body ground |
Ignition switch off |
10 kΩ or higher |
|
A187-9 (IGC2) - Body ground |
Ignition switch off |
10 kΩ or higher |
(d) Reconnect the inverter with converter assembly connector.
| NG | | GO TO STEP 7 |
|
|
6. | REPLACE INVERTER WITH CONVERTER ASSEMBLY |
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| NEXT | | REPLACE FUSE (PCU NO. 1) |
|
7. | REPAIR OR REPLACE HARNESS OR CONNECTOR |
| NEXT | | REPLACE FUSE (PCU NO. 1) |
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Click here
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1.
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