| Last Modified: 05-13-2024 | 6.11:8.1.0 | Doc ID: RM1000000026ZCV |
| Model Year Start: 2023 | Model: Corolla | Prod Date Range: [09/2022 - ] |
| Title: 2ZR-FXE (ENGINE CONTROL): SFI SYSTEM: ECM Power Source Circuit; 2023 - 2025 MY Corolla Corolla HV [09/2022 - ] | ||
|
ECM Power Source Circuit |
DESCRIPTION
When the power switch is turned on (IG), auxiliary battery voltage is applied to the IGP terminal of the ECM. When the transistor in the MREL circuit operates, current flows from the auxiliary battery to ground through the drive circuit of the EFI-MAIN NO. 1 relay, thus operating the relay which supplies power to the +B and +B2 terminals of the ECM.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
Inspect the fuses for circuits related to this system before performing the following procedure.
PROCEDURE
|
1. |
CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) |
(a) Disconnect the ECM connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A46-17 (E1) - Body ground |
Always |
Below 1 Ω |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
2. |
CHECK TERMINAL VOLTAGE (IGP TERMINAL VOLTAGE) |
(a) Disconnect the ECM connector.
(b) Turn the power switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A46-41 (IGP) - Body ground |
Power switch on (IG) |
11 to 14 V |
| NG |
|
|
|
3. |
INSPECT EFI-MAIN NO. 1 RELAY |
Click here
![2023 - 2025 MY Corolla Corolla HV [09/2022 - ]; 2ZR-FXE (ENGINE CONTROL): RELAY: ON-VEHICLE INSPECTION+](/t3Portal/stylegraphics/info.gif)
| NG |
|
REPLACE EFI-MAIN NO. 1 RELAY |
|
|
4. |
CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 1 RELAY - ECM) |
(a) Remove the EFI-MAIN NO. 1 relay, EFI-MAIN NO.2 relay and EFI-MAIN NO.3 relayfrom the No. 1 engine room relay block and No. 1 junction block assembly.
HINT:
Remove the EFI-MAIN NO. 2 relay and EFI-MAIN NO. 3 relay connected between the checked terminals as the coil inside the relay influences the measurement value.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
2 (EFI-MAIN NO. 1 relay) - A46-27 (MREL) |
Always |
Below 1 Ω |
|
3 (EFI-MAIN NO. 1 relay) - A46-2 (+B) |
Always |
Below 1 Ω |
|
3 (EFI-MAIN NO. 1 relay) - A46-3 (+B2) |
Always |
Below 1 Ω |
|
2 (EFI-MAIN NO. 1 relay) or A46-27 (MREL) - Body ground and other terminals |
Always |
10 kΩ or higher |
|
3 (EFI-MAIN NO. 1 relay), A46-2 (+B) or A46-3 (+B2) - Body ground and other terminals |
Always |
10 kΩ or higher |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
5. |
CHECK TERMINAL VOLTAGE (POWER SOURCE OF EFI-MAIN NO. 1 RELAY) |
(a) Remove the EFI-MAIN NO. 1 relay from the No. 1 engine room relay block and No. 1 junction block assembly.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
5 (EFI-MAIN NO. 1 relay) - Body ground |
Always |
11 to 14 V |
|
1 (EFI-MAIN NO. 1 relay) - Body ground |
Always |
11 to 14 V |
| OK |
|
REPLACE ECM
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (AUXILIARY BATTERY - EFI-MAIN NO. 1 RELAY) |
|
6. |
INSPECT IGP-MAIN RELAY |
Click here
| NG |
|
REPLACE IGP-MAIN RELAY |
|
|
7. |
CHECK HARNESS AND CONNECTOR (IGP-MAIN RELAY - ECM) |
(a) Disconnect the ECM connector.
(b) Remove the IGP-MAIN relay from the No. 1 engine room relay block and No. 1 junction block assembly.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
3 (IGP-MAIN relay) - A46-41 (IGP) |
Always |
Below 1 Ω |
|
3 (IGP-MAIN relay) or A46-41 (IGP) - Body ground and other terminals |
Always |
10 kΩ or higher |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
8. |
CHECK TERMINAL VOLTAGE (POWER SOURCE OF IGP-MAIN RELAY) |
(a) Remove the IGP-MAIN relay from the No. 1 engine room relay block and No. 1 junction block assembly.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
5 (IGP-MAIN relay) - Body ground |
Always |
11 to 14 V |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (AUXILIARY BATTERY - IGP-MAIN RELAY) |
|
|
9. |
CHECK HARNESS AND CONNECTOR (IGP-MAIN RELAY - BODY GROUND) |
(a) Remove the IGP-MAIN relay 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 |
|---|---|---|
|
2 (IGP-MAIN relay) - Body ground |
Always |
Below 1 Ω |
|
Result |
Proceed to |
|---|---|
|
OK (w/ Smart Key System) |
A |
|
OK (w/o Smart Key System) |
B |
|
NG |
C |
| B |
|
| C |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
10. |
CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - IGP-MAIN RELAY) |
(a) Disconnect the certification ECU (smart key ECU assembly) connector.
(b) Remove the IGP-MAIN relay from the No. 1 engine room relay block and No. 1 junction block assembly.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
O175-24 (IGPD) - 1 (IGP-MAIN relay) |
Always |
Below 1 Ω |
|
O175-24 (IGPD) or 1 (IGP-MAIN relay) - Body ground and other terminals |
Always |
10 kΩ or higher |
| OK |
|
GO TO SMART KEY SYSTEM
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
11. |
INSPECT IGNITION OR STARTER SWITCH ASSEMBLY |
Click here
| NG |
|
|
|
12. |
CHECK HARNESS AND CONNECTOR (IGNITION OR STARTER SWITCH ASSEMBLY - IGP-MAIN RELAY) |
(a) Disconnect the ignition or starter switch assembly connector.
(b) Remove the IGP-MAIN relay from the No. 1 engine room relay block assembly.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
I12-8 (IG1) - 1 (IGP-MAIN relay) |
Always |
Below 1 Ω |
|
I12-8 (IG1) or 1 (IGP-MAIN relay) - Body ground and other terminals |
Always |
10 kΩ or higher |
| OK |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (AUXILIARY BATTERY - IGNITION OR STARTER SWITCH ASSEMBLY) |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|