| Last Modified: 07-31-2024 | 6.11:8.1.0 | Doc ID: RM10000000260SH |
| Model Year Start: 2023 | Model: GR Corolla | Prod Date Range: [09/2022 - ] |
| Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for Gasoline Model without Electric Parking Brake System TMC Made): Brake Warning Light Remains ON; 2023 - 2025 MY Corolla Corolla Hatchback GR Corolla [09/2022 - ] | ||
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Brake Warning Light Remains ON |
DESCRIPTION
This procedure is for troubleshooting when the brake system warning light (red indicator) remains on but no DTCs are output.
The skid control ECU (brake actuator assembly) controls the brake system warning light (red indicator) in the combination meter assembly via CAN communication.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
Before performing this procedure, depress the brake pedal and confirm that the stop lights illuminate.
PROCEDURE
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1. |
PRE-CHECK |
(a) Check that all of the following conditions required for the brake system warning light (red indicator) to turn off are met:
(1) The ABS warning light is not illuminated.
HINT:
If the ABS warning light remains illuminated, make sure that the conditions required for the ABS warning light to turn off are met.
Click here
![2023 MY Corolla Corolla Hatchback GR Corolla [09/2022 - 11/2022]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for Gasoline Model without Electric Parking Brake System TMC Made): PROBLEM SYMPTOMS TABLE](/t3Portal/stylegraphics/info.gif)
(2) The brake fluid level in the brake master cylinder reservoir assembly is not low.
(3) Ensure that the brake booster has sufficient vacuum.
HINT:
When the vacuum inside the brake booster decreases, the brake system warning light (red indicator) comes on.
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2. |
INSPECT BRAKE MASTER CYLINDER RESERVOIR ASSEMBLY |
(a) With a sufficient level of brake fluid, disconnect the A67 brake fluid level warning switch (brake master cylinder reservoir assembly) connector and confirm that the brake system warning light (red indicator) illuminates.
OK:
The brake system warning light (red indicator) does not turn off.
HINT:
If the brake system warning light (red indicator) turns off, there is a short in the brake fluid level warning switch (brake master cylinder reservoir assembly) circuit.
| NG |
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3. |
CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - BRAKE MASTER CYLINDER RESERVOIR ASSEMBLY) |
(a) Turn the ignition switch off.
(b) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
OK:
The connector is securely connected.
(c) Disconnect the I4 combination meter assembly connector.
(d) Check both the connector case and the terminals for deformation and corrosion.
OK:
No deformation or corrosion.
(e) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
I4-11 (SW) - A67-1 (+) |
Always |
Below 1 Ω |
|
I4-11 (SW) or A67-1 (+) - Body ground |
Always |
10 kΩ or higher |
|
A67-2 (E) - Body ground |
1 minute or more after disconnecting the cable from the negative (-) battery terminal |
Below 1 Ω |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
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4. |
INSPECT VACUUM WARNING SWITCH ASSEMBLY |
(a) Inspect the vacuum warning switch assembly.
Click here
OK:
The vacuum warning switch assembly is normal.
| NG |
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REPLACE VACUUM WARNING SWITCH ASSEMBLY
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5. |
CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - VACUUM WARNING SWITCH ASSEMBLY) |
(a) Disconnect the A65 vacuum warning switch assembly connector.
(b) Disconnect the I4 combination meter assembly connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
I4-27 (VCM) - A65-2 (+) |
Always |
Below 1 Ω |
|
I4-27 (VCM) or A65-2 (+) - Body ground |
Always |
10 kΩ or higher |
|
A65-1 (E) - Body ground |
1 minute or more after disconnecting the cable from the negative (-) battery terminal |
Below 1 Ω |
| NG |
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REPAIR OR REPLACE HARNESS OR CONNECTOR |
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6. |
INSPECT COMBINATION METER ASSEMBLY |
(a) Reconnect the I4 combination meter assembly connector.
(b) Reconnect the A67 brake fluid level warning switch (brake master cylinder reservoir assembly) connector.
(c) Perform the Active Test of the combination meter assembly using the GTS.
Body Electrical > Combination Meter > Active Test
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Tester Display |
|---|
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Multi Display All (White) |
(d) Check the combination meter assembly.
OK:
The multi-information display turns on or off in accordance with GTS operation.
| OK |
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REPLACE BRAKE ACTUATOR ASSEMBLY
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| NG |
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INSPECT METER / GAUGE SYSTEM
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