Last Modified: 07-31-2024 6.11:8.1.0 Doc ID: RM1000000026ZD4
Model Year Start: 2023 Model: Corolla Prod Date Range: [09/2022 -           ]
Title: 2ZR-FXE (ENGINE CONTROL): SFI SYSTEM: Fuel Injector Circuit; 2023 - 2025 MY Corolla Corolla HV [09/2022 -        ]

Fuel Injector Circuit

DESCRIPTION

The fuel injector assemblies are located in each intake port and inject fuel into the cylinders based on the signals from 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 TERMINAL VOLTAGE (POWER SOURCE OF FUEL INJECTOR ASSEMBLY)

*a

Front view of wire harness connector

(to Fuel Injector Assembly)

(a) Disconnect the fuel injector assembly 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

C33-1 (#1) - Body ground

Power switch on (IG)

11 to 14 V

C34-1 (#2) - Body ground

Power switch on (IG)

11 to 14 V

C35-1 (#3) - Body ground

Power switch on (IG)

11 to 14 V

C36-1 (#4) - Body ground

Power switch on (IG)

11 to 14 V

NG

GO TO STEP 4

OK

2.

INSPECT FUEL INJECTOR ASSEMBLY (INJECTION AND VOLUME)

(a) Inspect the fuel injector assembly.

Click here 2020 - 2025 MY Corolla Corolla HV [01/2019 -        ]; 2ZR-FXE (FUEL): FUEL INJECTOR: INSPECTION

HINT:

Perform "Inspection After Repair" after replacing the fuel injector assembly.

Click here 2023 - 2025 MY Corolla Corolla HV [09/2022 -        ]; 2ZR-FXE (ENGINE CONTROL): SFI SYSTEM: INITIALIZATION

NG

REPLACE FUEL INJECTOR ASSEMBLY 2023 MY Corolla Corolla HV [09/2022 - 11/2022]; 2ZR-FXE (FUEL): FUEL INJECTOR: REMOVAL 2023 - 2025 MY Corolla Corolla HV [11/2022 -        ]; 2ZR-FXE (FUEL): FUEL INJECTOR: REMOVAL

OK

3.

CHECK HARNESS AND CONNECTOR (FUEL INJECTOR ASSEMBLY - ECM)

(a) Disconnect the fuel injector assembly 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

C33-2 (#10) - C147-34 (#10)

Always

Below 1 Ω

C34-2 (#20) - C147-35 (#20)

Always

Below 1 Ω

C35-2 (#30) - C147-36 (#30)

Always

Below 1 Ω

C36-2 (#40) - C147-37 (#40)

Always

Below 1 Ω

C33-2 (#10) or C147-34 (#10) - Body ground and other terminals

Always

10 kΩ or higher

C34-2 (#20) or C147-35 (#20) - Body ground and other terminals

Always

10 kΩ or higher

C35-2 (#30) or C147-36 (#30) - Body ground and other terminals

Always

10 kΩ or higher

C36-2 (#40) or C147-37 (#40) - Body ground and other terminals

Always

10 kΩ or higher

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.

CHECK HARNESS AND CONNECTOR (IGP-MAIN RELAY - FUEL INJECTOR ASSEMBLY)

(a) Disconnect the IGP-MAIN relay from No. 1 engine room relay block and No. 1 junction block assembly.

(b) Disconnect the fuel injector assembly connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

3 (IGP-MAIN relay) - C33-1 (#1)

Always

Below 1 Ω

3 (IGP-MAIN relay) - C34-1 (#2)

Always

Below 1 Ω

3 (IGP-MAIN relay) - C35-1 (#3)

Always

Below 1 Ω

3 (IGP-MAIN relay) - C36-1 (#4)

Always

Below 1 Ω

3 (IGP-MAIN relay) or C33-1 (#1) - Body ground and other terminals

Always

10 kΩ or higher

3 (IGP-MAIN relay) or C34-1 (#2) - Body ground and other terminals

Always

10 kΩ or higher

3 (IGP-MAIN relay) or C35-1 (#3) - Body ground and other terminals

Always

10 kΩ or higher

3 (IGP-MAIN relay) or C36-1 (#4) - 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.

OK

GO TO ECM POWER SOURCE CIRCUIT

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR