Last Modified: 05-13-2024 |
6.11:8.1.0 |
Doc ID: RM1000000027APQ |
Model Year Start: 2023 |
Model: Corolla |
Prod Date Range: [09/2022 - 11/2022] |
Title: 2ZR-FAE (ENGINE CONTROL): SFI SYSTEM: ECM Power Source Circuit; 2023 MY Corolla [09/2022 - 11/2022] |
DESCRIPTION
When the ignition switch is turned to ON, the battery voltage is applied to IGSW of the ECM. The output signal from the MREL terminal of the ECM causes a current to flow to the coil, closing the contacts of the EFI-MAIN relay and supplying power to either terminal +B or +B2 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
|
C77-59 (E1) - Body ground
|
Always
|
Below 1 Ω
|
NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR
|
OK
|
|
|
2.
|
CHECK TERMINAL VOLTAGE (IGSW TERMINAL VOLTAGE)
|
*a
|
Front view of wire harness connector
(to ECM)
|
(a) Disconnect the ECM connector.
(b) Turn the ignition switch to ON.
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection
|
Condition
|
Specified Condition
|
A46-6 (IGSW) - Body ground
|
Ignition switch ON
|
11 to 14 V
|
OK
|
|
|
3.
|
INSPECT EFI-MAIN RELAY
|
(a) Inspect the EFI-MAIN relay.
Click here
NG |
|
REPLACE EFI-MAIN RELAY
|
OK
|
|
|
4.
|
CHECK HARNESS AND CONNECTOR (EFI-MAIN RELAY - BODY GROUND)
|
(a) Remove the EFI-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 (EFI-MAIN relay) - Body ground
|
Always
|
Below 1 Ω
|
NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR
|
OK
|
|
|
5.
|
CHECK HARNESS AND CONNECTOR (EFI-MAIN RELAY - ECM)
|
(a) Disconnect the ECM connector.
(b) Remove the EFI-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
|
1 (EFI-MAIN relay) - A46-46 (MREL)
|
Always
|
Below 1 Ω
|
3 (EFI-MAIN relay) - A46-2 (+B)
|
Always
|
Below 1 Ω
|
3 (EFI-MAIN relay) - A46-3 (+B2)
|
Always
|
Below 1 Ω
|
1 (EFI-MAIN relay) or A46-46 (MREL) - Body ground and other terminals
|
Always
|
10 kΩ or higher
|
3 (EFI-MAIN relay), A46-2 (+B) or A46-3 (+B2) - Body ground and other terminals
|
Always
|
10 kΩ or higher
|
HINT:
If a short is detected in any of the above circuits, there may be a malfunction in the circuit of a connected ECU.
NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR
|
OK
|
|
|
6.
|
CHECK TERMINAL VOLTAGE (POWER SOURCE OF EFI-MAIN RELAY)
|
*1
|
NO. 1 Engine Room Relay Block and NO. 1 Junction Block Assembly
|
*2
|
EFI-MAIN Relay
|
(a) Remove the EFI-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 (EFI-MAIN relay) - Body ground
|
Always
|
11 to 14 V
|
NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - EFI-MAIN RELAY)
|
7.
|
CHECK TERMINAL VOLTAGE (POWER SOURCE OF NO. 1 INTEGRATION RELAY)
|
*a
|
Front view of wire harness connector
(to No. 1 Integration Relay)
|
(a) Disconnect the No. 1 integration relay connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection
|
Condition
|
Specified Condition
|
1A-10 - Body ground
|
Always
|
11 to 14 V
|
NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - NO. 1 INTEGRATION RELAY)
|
OK
|
|
|
8.
|
INSPECT NO. 1 INTEGRATION RELAY (IG2 NO. 1 RELAY)
|
(a) Inspect the No. 1 integration relay (IG2 NO. 1 relay).
Click here
OK
|
|
|
9.
|
CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - ECM)
|
(a) Disconnect the No. 1 integration relay connector.
(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
|
1A-9 - A46-6 (IGSW)
|
Always
|
Below 1 Ω
|
1A-9 or A46-6 (IGSW) - Body ground and other terminals
|
Always
|
10 kΩ or higher
|
HINT:
If a short is detected in any of the above circuits, there may be a malfunction in the circuit of a connected ECU.
NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR
|
OK
|
|
|
10.
|
CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - BODY GROUND)
|
(a) Disconnect the No. 1 integration relay connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
|
Condition
|
Specified Condition
|
1A-8 - Body ground
|
Always
|
Below 1 Ω
|
Result
|
Proceed to
|
OK (w/ Smart Key System)
|
A
|
OK (w/o Smart Key System)
|
B
|
NG
|
C
|
C |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR
|
A
|
|
|
11.
|
CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - NO. 1 INTEGRATION RELAY)
|
(a) Disconnect the certification ECU (smart key ECU assembly) connector.
(b) Disconnect the No. 1 integration relay connector.
(c) Disconnect the instrument panel junction block assembly 4F connector.
HINT:
Disconnect the IG1-NO. 1, IG1-NO. 2 and IG2-NO. 2 relays connected between the checked terminals as the coil inside the relay influences the measurement value.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
|
Condition
|
Specified Condition
|
I1-15 (IG1D) - 1A-7
|
Always
|
Below 1 Ω
|
I1-15 (IG1D) or 1A-7 - Body ground and other terminals
|
Always
|
10 kΩ or higher
|
NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR
|
12.
|
INSPECT IGNITION OR STARTER SWITCH ASSEMBLY
|
(a) Inspect the ignition or starter switch assembly.
Click here
OK
|
|
|
13.
|
CHECK HARNESS AND CONNECTOR (IGNITION OR STARTER SWITCH ASSEMBLY - NO. 1 INTEGRATION RELAY)
|
(a) Disconnect the ignition or starter switch assembly connector.
(b) Disconnect the No. 1 integration relay connector.
(c) Disconnect the instrument panel junction block assembly 4F connector.
HINT:
Disconnect the IG1-NO. 1, IG1-NO. 2 and IG2-NO. 2 relays connected between the checked terminals as the coil inside the relay influences the measurement value.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
|
Condition
|
Specified Condition
|
I12-8 (IG1) - 1A-7
|
Always
|
Below 1 Ω
|
I12-8 (IG1) or 1A-7 - Body ground and other terminals
|
Always
|
10 kΩ or higher
|
OK |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - IGNITION OR STARTER SWITCH ASSEMBLY)
|
NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR
|
|