Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Brake Warning Light Remains ON: Procedure
- CHECK DTC
- Check if the ABS, VSC and/or electronically controlled brake system DTC is output. Refer to DTC CHECK / CLEAR
.RESULT
Result Proceed to DTC is not output A DTC is output B
B → See step 8
A: Go to next step
- Check if the ABS, VSC and/or electronically controlled brake system DTC is output. Refer to DTC CHECK / CLEAR
.
- INSPECT CAN COMMUNICATION SYSTEM
- Check if the CAN communication system DTC is output. Refer to DIAGNOSTIC TROUBLE CODE CHART
.RESULT
Result Proceed to DTC is not output A DTC is output B
B → See step 9
A: Go to next step
- Check if the CAN communication system DTC is output. Refer to DIAGNOSTIC TROUBLE CODE CHART
.
- INSPECT IF SKID CONTROL ECU CONNECTOR IS SECURELY CONNECTED
- Check the skid control ECU connector's connection.
OK
The connector is securely connected.
NG → CONNECT CONNECTOR TO ECU CORRECTLY
OK: Go to next step
- Check the skid control ECU connector's connection.
- INSPECT BATTERY
- Check the battery voltage.
Standard voltage
11 to 14 V
NG → See step 10
OK: Go to next step
- Check the battery voltage.
- CHECK TERMINAL VOLTAGE (IG1, IG2)
- Disconnect the A19 and A21 ECU connectors.
- Turn the engine switch on (IG).
- Measure the voltage according to the value(s) in the table below.
Standard voltage
Tester Connection Switch Condition Specified Condition A19-46 (IG1) - A19-1 (GND) Engine switch on (IG) 11 to 14 V A21-46 (IG2) - A21-1 (GND4) Engine switch on (IG) 11 to 14 V - Measure the resistance according to the value(s) in the table below.
Standard resistance
Tester Connection Condition Specified Condition A19-1 (GND) - Body ground Always Below 1 Ω A21-1 (GND4) - Body ground Always Below 1 Ω
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 CIRCUIT)
OK: Go to next step
- INSPECT COMBINATION METER ASSEMBLY
- Check the combination meter. Refer to HOW TO PROCEED WITH TROUBLESHOOTING
.
HINT:
If troubleshooting has been carried out according to the PROBLEM SYMPTOMS TABLE, refer back to the table and proceed to the next step before replacing the part. Refer to PROBLEM SYMPTOMS TABLE .
NG → See step 11
OK → See step 7
- Check the combination meter. Refer to HOW TO PROCEED WITH TROUBLESHOOTING
.
- REPLACE SKID CONTROL ECU. Refer to REMOVAL
- REPAIR CIRCUIT INDICATED BY OUTPUT CODE. Refer to DIAGNOSTIC TROUBLE CODE CHART
- GO TO CAN COMMUNICATION SYSTEM. Refer to HOW TO PROCEED WITH TROUBLESHOOTING
- INSPECT CHARGING SYSTEM. Refer to ON-VEHICLE INSPECTION
- REPLACE COMBINATION METER ASSEMBLY. Refer to REMOVAL
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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