| Last Modified: 05-13-2024 | 6.11:8.1.0 | Doc ID: RM100000001GEI2 |
| Model Year Start: 2020 | Model: Corolla | Prod Date Range: [01/2019 - 09/2022] |
| Title: 2ZR-FXE (ENGINE CONTROL): SFI SYSTEM: VC Output Circuit; 2020 - 2022 MY Corolla Corolla HV [01/2019 - 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
![2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]; 2ZR-FXE (ENGINE CONTROL): SFI SYSTEM: ECM Power Source Circuit+](/t3Portal/stylegraphics/info.gif)
-
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
|
|
|
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 |
|
|
|
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
| B |
|
|
|
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 |
|
|
|
5. |
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 |
|
| C |
|
|
|
6. |
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 |
|
|
|
7. |
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 |
|
| B |
|
REPLACE FUEL TANK PRESSURE SENSOR
|
|
8. |
CHECK HARNESS AND CONNECTOR |
(a) Disconnect the throttle body assembly connector.
(b) Disconnect the crankshaft position sensor connector.
(c) Disconnect the manifold absolute pressure sensor connector.
(d) Disconnect the canister pump module connector.*
(e) Disconnect the fuel tank pressure sensor connector.*
(f) Disconnect the ECM connectors.
(g) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
C77-134 (VCTA) - Body ground |
Always |
10 kΩ or higher |
|
C77-116 (VCV1) - Body ground |
Always |
10 kΩ or higher |
|
C77-77 (VCPM) - Body ground |
Always |
10 kΩ or higher |
|
A46-55 (VCPP)* - Body ground |
Always |
10 kΩ or higher |
|
C77-92 (VPTK)* - 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 |
|
A46-2 (+B) - Body ground |
Always |
10 kΩ or higher |
|
A46-3 (+B2) - Body ground |
Always |
10 kΩ or higher |
*:w/ Canister Pump Module
| OK |
|
REPLACE ECM
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|