| Last Modified: 05-13-2024 | 6.11:8.1.0 | Doc ID: RM100000001HBR8 |
| Model Year Start: 2020 | Model: Corolla Hatchback | Prod Date Range: [01/2019 - 11/2022] |
| Title: M20A-FKS (COOLING): COOLING FAN SYSTEM (w/o Cooling Fan ECU): Cooling Fan Circuit; 2020 - 2023 MY Corolla Corolla Hatchback [01/2019 - 11/2022] | ||
|
Cooling Fan Circuit |
DESCRIPTION
The ECM calculates an appropriate cooling fan speed based on the engine coolant temperature, air conditioning switch status, refrigerant pressure, engine speed and vehicle speed, and sends a signal to the cooling fan ECU (fan with motor assembly). The cooling fan ECU (fan with motor assembly) steplessly control the speed of the cooling fan based on the duty cycle signal sent from the ECM. By sending signals to the cooling fan ECU (fan with motor assembly) in accordance with the driving conditions and by controlling the cooling fan speed optimally with the ECM, both high cooling performance and quietness are ensured.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
- Inspect the fuses for circuits related to this system before performing the following procedure.
- Before replacing the ECM, refer to Service Bulletin.
PROCEDURE
|
1. |
PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE ENGINE COOLING FAN DUTY RATIO) |
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine / Active Test / Control the Engine Cooling Fan Duty Ratio.
Powertrain > Engine > Active Test
|
Tester Display |
|---|
|
Control the Engine Cooling Fan Duty Ratio |
(e) Check the operation of the cooling fan while operating it using the Techstream.
OK:
|
Tester Operation |
Fan Operation |
|---|---|
|
30 - 100% |
Cooling fan operates |
|
0% |
Cooling fan stops |
(f) Turn the ignition switch to ON.
|
Result |
Proceed to |
|---|---|
|
OK |
A |
|
NG (Cooling fan does not operate) |
B |
|
NG (Cooling fan does not stop) |
C |
| A |
|
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
| C |
|
|
|
2. |
CHECK HARNESS AND CONNECTOR (COOLING FAN MOTOR POWER SOURCE CIRCUIT) |
(a) Disconnect the A63 cooling fan motor connector.
|
(b) Measure the voltage according to the value(s) in the table below. Standard Voltage:
|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN MOTOR POWER SOURCE CIRCUIT) |
|
|
3. |
CHECK HARNESS AND CONNECTOR (COOLING FAN MOTOR - NO. 1 INTEGRATION RELAY) |
(a) Disconnect the A63 cooling fan motor 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 (Check for Open):
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A63-4 (IGS1) - 1B-4 |
Always |
Below 1 Ω |
Standard Resistance (Check for Short):
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A63-4 (IGS1) or 1B-4 - Body ground |
Always |
10 kΩ or higher |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN MOTOR - NO. 1 INTEGRATION RELAY) |
|
|
4. |
CHECK HARNESS AND CONNECTOR (COOLING FAN MOTOR - BODY GROUND) |
(a) Disconnect the A63 cooling fan motor connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A63-2 (E1) - Body ground |
Always |
Below 1 Ω |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN MOTOR - BODY GROUND) |
|
|
5. |
CHECK HARNESS AND CONNECTOR (COOLING FAN MOTOR - ECM) |
(a) Disconnect the A47 ECM connector.
(b) Disconnect the A63 cooling fan motor connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A63-3 (SI) - A47-32 (RFC) |
Always |
Below 1 Ω |
Standard Resistance (Check for Short):
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A63-3 (SI) or A47-32 (RFC) - Body ground |
Always |
10 kΩ or higher |
| OK |
|
REPLACE COOLING FAN MOTOR
|
![2019 - 2020 MY Corolla Corolla Hatchback [06/2018 - 09/2019]; M20A-FKS (COOLING): COOLING FAN MOTOR (w/o Cooling Fan ECU): REMOVAL](/t3Portal/stylegraphics/info.gif)
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN MOTOR - ECM) |
|
6. |
CHECK HARNESS AND CONNECTOR (COOLING FAN MOTOR - ECM) |
(a) Disconnect the A47 ECM connector.
(b) Disconnect the A63 cooling fan motor connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A47-32 (RFC) - A63-3(SI) |
Always |
Below 1 Ω |
| OK |
|
REPLACE COOLING FAN MOTOR
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (COOLING FAN MOTOR - ECM) |
|
|