Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM1000000026ZCZ
Model Year Start: 2023 Model: Corolla Prod Date Range: [09/2022 -           ]
Title: 2ZR-FXE (ENGINE CONTROL): SFI SYSTEM: VC Output Circuit; 2023 - 2025 MY Corolla Corolla HV [09/2022 -        ]

VC Output Circuit

DESCRIPTION

The ECM constantly generates 5 V power source voltage from the auxiliary battery voltage supplied to the +B, +B2 (BATT) terminal of the ECM to operate the microprocessor. The ECM also provides this power source voltage to the sensors through the VC output circuit.

When the VC circuit has a short circuit, the microprocessor in the ECM and sensors that are supplied power through the VC circuit are deactivated because power is not supplied from the VC circuit. When the system is in this condition, it will not start.

WIRING DIAGRAM

  • For the circuit diagram of the ECM power source refer to the ECM power source circuit.

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

  • VC Output Circuit

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.

CHECK TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Check the communication between the Techstream and ECM.

HINT:

Communication can be checked by using the Data List item Engine.

Result

Proceed to

Communication is not possible

A

Communication is possible

B
B

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

A

2.

CHECK EFI NO. 2 FUSE VOLTAGE

*1

No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

*2

EFI NO. 2 Fuse

(a) Turn the power switch on (IG).

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

1 (EFI NO. 2 fuse) - Body ground

Power switch on (IG)

11 to 14 V

HINT:

  • Check the fuse with it installed to the No. 1 engine room relay block and No. 1 junction block assembly.
  • If the result is not as specified, since current is not flowing to the +B and +B2 terminals of the ECM, the system may not be started.
NG

GO TO ECM POWER SOURCE CIRCUIT

OK

3.

CHECK CONNECTION BETWEEN TECHSTREAM AND ECM (THROTTLE POSITION SENSOR)

(a) Disconnect the throttle body assembly connector.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Check the communication between the Techstream and ECM.

HINT:

Communication can be checked by using the Data List item Engine.

Result

Proceed to

Communication is not possible

A

Communication is possible

B

HINT:

Perform "Inspection After Repair" after replacing the throttle body assembly.

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

B

REPLACE THROTTLE BODY ASSEMBLY

A

4.

CHECK CONNECTION BETWEEN TECHSTREAM AND ECM (CAMSHAFT POSITION SENSOR)

(a) Disconnect the camshaft position sensor connector.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Check the communication between the Techstream and ECM.

HINT:

Communication can be checked by using the Data List item Engine.

Result

Proceed to

Communication is not possible

A

Communication is possible

B
B

REPLACE CAMSHAFT POSITION SENSOR

A

5.

CHECK CONNECTION BETWEEN TECHSTREAM AND ECM (CRANKSHAFT POSITION SENSOR)

(a) Disconnect the crankshaft position sensor connector.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Check the communication between the Techstream and ECM.

HINT:

Communication can be checked by using the Data List item Engine.

Result

Proceed to

Communication is not possible

A

Communication is possible

B
B

REPLACE CRANKSHAFT POSITION SENSOR

A

6.

CHECK CONNECTION BETWEEN TECHSTREAM AND ECM (MASS AIR FLOW METER SUB-ASSEMBLY)

(a) Disconnect the mass air flow meter sub-assembly connector.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Check the communication between the Techstream and ECM.

HINT:

Communication can be checked by using the Data List item Engine.

Result

Proceed to

Communication is not possible

A

Communication is possible

B

HINT:

Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly.

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

B

REPLACE MASS AIR FLOW METER SUB-ASSEMBLY

A

7.

CHECK CONNECTION BETWEEN TECHSTREAM AND ECM (MANIFOLD ABSOLUTE PRESSURE SENSOR)

(a) Disconnect the manifold absolute pressure sensor connector.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Check the communication between the Techstream and ECM.

HINT:

Communication can be checked by using the Data List item Engine.

Result

Proceed to

Communication is not possible (w Canister Pump Module)

A

Communication is not possible (w/o Canister Pump Module)

B

Communication is possible

C
B

GO TO STEP 10

C

REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR

A

8.

CHECK CONNECTION BETWEEN TECHSTREAM AND ECM (CANISTER PUMP MODULE)

(a) Disconnect the canister pump module connector.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Check the communication between the Techstream and ECM.

HINT:

Communication can be checked by using the Data List item Engine.

Result

Proceed to

Communication is not possible

A

Communication is possible

B
B

REPLACE CANISTER PUMP MODULE

A

9.

CHECK CONNECTION BETWEEN TECHSTREAM AND ECM (FUEL TANK PRESSURE SENSOR)

(a) Disconnect the fuel tank pressure sensor connector.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Check the communication between the Techstream and ECM.

HINT:

Communication can be checked by using the Data List item Engine.

Result

Proceed to

Communication is not possible

A

Communication is possible

B
A

GO TO STEP 10

B

REPLACE FUEL TANK PRESSURE SENSOR

10.

CHECK HARNESS AND CONNECTOR

(a) Disconnect the throttle body assembly connector.

(b) Disconnect the camshaft position sensor connector.

(c) Disconnect the crankshaft position sensor connector.

(d) Disconnect the manifold absolute pressure sensor connector.

(e) Disconnect the mass air flow meter sub-assembly connector.

(f) Disconnect the canister pump module connector.*

(g) Disconnect the fuel tank pressure sensor connector.*

(h) Disconnect the ECM connectors.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

C147-134 (VCTA) - Body ground

Always

10 kΩ or higher

C147-114 (VCV1) - Body ground

Always

10 kΩ or higher

C147-89 (VCPM) - Body ground

Always

10 kΩ or higher

A46-56 (VCPP)* - Body ground

Always

10 kΩ or higher

A46-54 (VPTK)* - Body ground

Always

10 kΩ or higher

C147-108 (VCVG) - Body ground

Always

10 kΩ or higher

C147-82 (VCNE) - Body ground

Always

10 kΩ or higher

A46-2 (+B) - 1 (EFI NO. 2 fuse)

Always

Below 1 Ω

A46-3 (+B2) - 1 (EFI NO. 2 fuse)

Always

Below 1 Ω

*:w/ Canister Pump Module

OK

REPLACE ECM 2023 MY Corolla Corolla HV [09/2022 - 11/2022]; 2ZR-FXE (ENGINE CONTROL): ECM: REMOVAL 2023 - 2025 MY Corolla Corolla HV [11/2022 -        ]; 2ZR-FXE (ENGINE CONTROL): ECM: REMOVAL

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR