Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001GKC8
Model Year Start: 2020 Model: Corolla Prod Date Range: [01/2019 - 11/2022]
Title: 2ZR-FAE (ENGINE CONTROL): SFI SYSTEM: Fuel Injector Circuit; 2020 - 2023 MY Corolla [01/2019 - 11/2022]

Fuel Injector Circuit

DESCRIPTION

The fuel injectors are located on the intake manifold. They 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)

*b

No. 1 Fuel Injector Assembly

*c

No. 2 Fuel Injector Assembly

*d

No. 3 Fuel Injector Assembly

*e

No. 4 Fuel Injector Assembly

(a) Disconnect the fuel injector assembly connectors.

(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

C33-1 (#1) - Body ground

Ignition switch ON

11 to 14 V

C34-1 (#2) - Body ground

Ignition switch ON

11 to 14 V

C35-1 (#3) - Body ground

Ignition switch ON

11 to 14 V

C36-1 (#4) - Body ground

Ignition switch ON

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 - 2023 MY Corolla [01/2019 - 11/2022]; 2ZR-FAE (FUEL): FUEL INJECTOR: INSPECTION

HINT:

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

Click here 2020 - 2023 MY Corolla [01/2019 - 11/2022]; 2ZR-FAE (ENGINE CONTROL): SFI SYSTEM: INITIALIZATION

NG

REPLACE FUEL INJECTOR ASSEMBLY 2020 MY Corolla [01/2019 - 03/2019]; 2ZR-FAE (FUEL): FUEL INJECTOR: REMOVAL 2020 - 2022 MY Corolla [03/2019 - 09/2022]; 2ZR-FAE (FUEL): FUEL INJECTOR: REMOVAL 2023 MY Corolla [09/2022 - 11/2022]; 2ZR-FAE (FUEL): FUEL INJECTOR: REMOVAL

OK

3.

CHECK HARNESS AND CONNECTOR (FUEL INJECTOR ASSEMBLY - ECM)

(a) Disconnect the fuel injector assembly connectors.

(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) - C77-98 (#10)

Always

Below 1 Ω

C34-2 (#20) - C77-95 (#20)

Always

Below 1 Ω

C35-2 (#30) - C77-96 (#30)

Always

Below 1 Ω

C36-2 (#40) - C77-97 (#40)

Always

Below 1 Ω

C33-2 (#10) or C77-98 (#10) - Body ground and other terminals

Always

10 kΩ or higher

C34-2 (#20) or C77-95 (#20) - Body ground and other terminals

Always

10 kΩ or higher

C35-2 (#30) or C77-96 (#30) - Body ground and other terminals

Always

10 kΩ or higher

C36-2 (#40) or C77-97 (#40) - Body ground and other terminals

Always

10 kΩ or higher

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE 2020 - 2022 MY Corolla [01/2019 - 09/2022]; 2ZR-FAE (ENGINE CONTROL): SFI SYSTEM: PROBLEM SYMPTOMS TABLE 2023 MY Corolla [09/2022 - 11/2022]; 2ZR-FAE (ENGINE CONTROL): SFI SYSTEM: PROBLEM SYMPTOMS TABLE

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.

CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - FUEL INJECTOR ASSEMBLY)

(a) Disconnect the No. 1 integration relay connector.

(b) Disconnect the fuel injector assembly connectors.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

1B-4 - C33-1 (#1)

Always

Below 1 Ω

1B-4 - C34-1 (#2)

Always

Below 1 Ω

1B-4 - C35-1 (#3)

Always

Below 1 Ω

1B-4 - C36-1 (#4)

Always

Below 1 Ω

1B-4 or C33-1 (#1) - Body ground and other terminals

Always

10 kΩ or higher

1B-4 or C34-1 (#2) - Body ground and other terminals

Always

10 kΩ or higher

1B-4 or C35-1 (#3) - Body ground and other terminals

Always

10 kΩ or higher

1B-4 or C36-1 (#4) - Body ground and other terminals

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

5.

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

1B-3 - Body ground

Always

11 to 14 V

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - NO. 1 INTEGRATION RELAY)

OK

6.

INSPECT NO. 1 INTEGRATION RELAY (EFI-MAIN RELAY)

(a) Inspect the No. 1 integration relay (EFI-MAIN relay).

Click here 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 09/2022]; POWER DISTRIBUTION: INTEGRATION RELAY: INSPECTION 2023 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2022 - 11/2022]; POWER DISTRIBUTION: INTEGRATION RELAY: INSPECTION

NG

REPLACE NO. 1 INTEGRATION RELAY 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; POWER DISTRIBUTION: INTEGRATION RELAY: REMOVAL 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]; POWER DISTRIBUTION: INTEGRATION RELAY: REMOVAL 2023 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2022 - 11/2022]; POWER DISTRIBUTION: INTEGRATION RELAY: REMOVAL

OK

7.

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

1B-6 - Body ground

Always

Below 1 Ω

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

8.

CHECK HARNESS AND CONNECTOR (EFI-MAIN RELAY - NO. 1 INTEGRATION RELAY)

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

(b) Disconnect the No. 1 integration relay connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

3 (EFI-MAIN relay) - 1B-5

Always

Below 1 Ω

3 (EFI-MAIN relay) or 1B-5 - Body ground and other terminals

Always

10 kΩ or higher

OK

GO TO ECM POWER SOURCE CIRCUIT 2020 - 2022 MY Corolla [01/2019 - 09/2022]; 2ZR-FAE (ENGINE CONTROL): SFI SYSTEM: ECM Power Source Circuit 2023 MY Corolla [09/2022 - 11/2022]; 2ZR-FAE (ENGINE CONTROL): SFI SYSTEM: ECM Power Source Circuit

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR