Toyota Corolla Cross: ECU Power Source Circuit
DESCRIPTION
If the ignition switch is ON, the battery ECU assembly applies current to the MREL terminal to turn the IGCT relay on. This supplies power to the IGCT terminals.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
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 BATTERY ECU ASSEMBLY (IGCT VOLTAGE) |
CAUTION:
Be sure to wear insulated gloves and protective goggles.
(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 battery ECU assembly connector. NOTICE: Before disconnecting the connector, check that it is not loose or disconnected. |
|
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(c) Connect the cable to the negative (-) auxiliary battery terminal.
(d) Turn the ignition switch to ON.
(e) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
O211-12 (IGCT) - Body ground |
Ignition switch ON |
11 to 14 V |
NOTICE:
- Turning the ignition switch to ON with the service plug grip removed causes other DTCs to be stored. Clear the DTCs after performing this inspection.
- If the ignition switch is turned to ON with the connectors disconnected, other DTCs will be stored. Be sure to clear the DTCs after the inspection.
(f) Turn the ignition switch off.
(g) Disconnect the cable from the negative (-) auxiliary battery terminal.
(h) Reconnect the battery ECU assembly connector.
| NG | .gif) | GO TO STEP 3 |
|
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2. | CHECK HARNESS AND CONNECTOR (BATTERY ECU ASSEMBLY - BODY GROUND) |
CAUTION:
Be sure to wear insulated gloves and protective goggles.
(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 battery ECU assembly connector. NOTICE: Before disconnecting the connector, check that it is not loose or disconnected. |
|
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
O211-10 (GND) - Body ground |
Always | Below 1 Ω |
(d) Reconnect the battery ECU assembly connector.
| OK | | GO TO PROBLEM SYMPTOMS TABLE |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
3. | CHECK FUSE (IGCT NO. 2) |
(a) Remove the IGCT NO. 2 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 |
|---|---|---|
|
IGCT NO. 2 fuse | Always |
Below 1 Ω |
(c) Install the IGCT NO. 2 fuse.
| NG | | GO TO STEP 6 |
|
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4. | CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY - BATTERY ECU ASSEMBLY) |
CAUTION:
Be sure to wear insulated gloves and protective goggles.
(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 battery ECU assembly connector. NOTICE: Before disconnecting the connector, check that it is not loose or disconnected. |
|
(c) Remove the IGCT NO. 2 fuse from the No. 1 engine room relay block and No. 1 junction block assembly.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
O211-12 (IGCT) - 2 (IGCT NO. 2 fuse holder) |
Always | Below 1 Ω |
(e) Install the IGCT NO. 2 fuse.
(f) Reconnect the battery ECU assembly connector.
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
5. | CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY) |
(a) Remove the IGCT-MAIN NO. 1 relay and IGCT NO. 2 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 |
|---|---|---|
|
3 (IGCT-MAIN NO. 1 relay holder) - 1 (IGCT NO. 2 fuse holder) |
Always | Below 1 Ω |
(c) Install the IGCT-MAIN NO. 1 relay and IGCT NO. 2 fuse.
| OK | | CHECK ECU Power Source Circuit (HYBRID CONTROL SYSTEM) |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
6. | CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY - BATTERY ECU ASSEMBLY) |
CAUTION:
Be sure to wear insulated gloves and protective goggles.
(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 battery ECU assembly connector. NOTICE: Before disconnecting the connector, check that it is not loose or disconnected. |
|
(c) Remove the IGCT NO. 2 fuse from the No. 1 engine room relay block and No. 1 junction block assembly.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
O211-12 (IGCT) or 2 (IGCT NO. 2 fuse holder) - Body ground and other terminals |
Always | 10 kΩ or higher |
(e) Install the IGCT NO. 2 fuse.
(f) Reconnect the battery ECU assembly connector.
| OK | | REPLACE FUSE (IGCT NO. 2) |
|
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7. | REPAIR OR REPLACE HARNESS OR CONNECTOR |
| NEXT | | REPLACE FUSE (IGCT NO. 2) |
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Precaution
PRECAUTION PRECAUTIONS FOR INSPECTING HYBRID SYSTEM
CAUTION:
Before the following operations are conducted, take precautions to prevent electric shock by turning the ignition switch off, wear
Definition Of Terms
DEFINITION OF TERMS
Term Definition
Monitor Description Description of what the hybrid vehicle control ECU monitors and how to detect malfunctions (monitoring purpose and its detai
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Terminals Of Ecu
TERMINALS OF ECU COMBINATION METER ASSEMBLY
(a) Measure the voltage and resistance according to the value(s) in the table below.
Terminal No. (Symbol) Terminal Description
Condition Specified Condition
I4-1 (EP) - Body ground
Ground Always
Below 1 Ω
I
