NO.3 BRAKE SYSTEM WARNING LIGHT STAY ON [DYNAMIC STABILITY CONTROL (DSC)]
id0403b2895800
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Brake system warning lights stay on |
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POSSIBLE CAUSE
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• Brake fluid amount is low.
• Electric Parking brake does not release.
• Electric Parking brake switch signal error input to instrument cluster.
• Brake fluid level sensor stuck on.
• Short to ground in following circuit:
• No connection at DSC HU/CM connector (When DSC HU/CM connector comes off, ABS warning light, brake system warning light, TCS/DSC indicator light, and TCS OFF indicator light illuminate.)
• DSC HU/CM detected malfunction. (Input and output device malfunction)
• DSC HU/CM detects low voltage in power supply.
• DSC HU/CM ground malfunction (When DSC HU/CM ground is not securely connected, ABS warning light, brake system warning light, TCS/DSC indicator light, and TCS OFF indicator light illuminate but diagnostic trouble code does not display.)
• DSC HU/CM does not operate.
• Front body control module (FBCM) detected malfunction.
• DSC HU/CM internal malfunction
• Instrument cluster detected malfunction
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Diagnostic procedure
STEP |
INSPECTION |
ACTION |
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1
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INSPECT BRAKE FLUID AMOUNT AND VERIFY THAT ELECTRIC PARKING BRAKE RELEASED
• Inspect the brake fluid amount and verify that the electric parking brake released.
• Is the brake fluid amount normal?
• Is the electric parking brake released?
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Yes
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Go to the next step.
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No
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Add the brake fluid or release the electric parking brake.
If the brake fluid refilled:
• Inspect and repair the brake line for leakage.
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2
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CONFIRM DSC HU/CM DTC
• Retrieve the DSC HU/CM DTC using the M-MDS.
• Are any DTCs present?
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Yes
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Go to the applicable DTC inspection.
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No
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If communication error message is displayed on the M-MDS screen:
• Go to the next step.
If communication error message is not displayed:
• Go to Step 4.
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3
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INSPECT CONNECTION OF DSC HU/CM CONNECTOR
• Inspect for connection of the DSC HU/CM connector.
• Is the DSC HU/CM connector connected securely?
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Yes
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Go to the next step.
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No
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Connect the DSC HU/CM connector securely, then go to the next step.
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4
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CONFIRM INSTRUMENT CLUSTER OPERATION RECORD
• Retrieve the warning system operation history using the M-MDS.
• Is the brake system warning light illumination history recorded?
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Yes
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If the Brake Waning Lamp recorded:
• Go to Step 5.
If the Brake Waning Lamp (Brake fluid low) recorded:
• Go to Step 6.
If the Brake Waning Lamp (Electric parking brake ON over 20 km/h or 12.4 mile/h) recorded:
• Go to Step 8.
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No
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Go to Step 10.
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5
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VERIFY WHETHER MALFUNCTION IS IN INSTRUMENT CLUSTER OR ELSEWHERE
• Connect the M-MDS to the DLC-2.
• Turn off and on all warning light and indicator lights using the instrument cluster PID WL+IL of active command modes.
• Do the ABS warning light, brake system warning light, TCS/DSC indicator light and DSC OFF indicator light turn on and off according to the active command modes?
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Yes
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Go to Step 10.
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No
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Replace the instrument cluster.
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6
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INSPECT WHETHER MALFUNCTION IS IN BRAKE FLUID LEVEL SENSOR OR ELSEWHERE
• Inspect the brake fluid level sensor for continuity.
• Is the continuity condition normal?
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Yes
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Go to the next step.
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No
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Replace the malfunctioning part.
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*7
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INSPECT FOR SHORT TO GROUND IN WIRING HARNESS BETWEEN FRONT BODY CONTROL MODULE (FBCM) AND BRAKE FLUID LEVEL SENSOR
• Inspect for short to ground in the following circuit:
• Is the short to ground detected?
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Yes
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Repair or replace the wiring harness for a possible short to ground.
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No
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Retrieve the front body control module (FBCM) DTC using the M-MDS.
If the DTC remains:
• Go to the applicable DTC inspection.
If the DTC does not remain:
• Replace the front body control module (FBCM).
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8
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INSPECT WHETHER MALFUNCTION IS IN ELECTRIC PARKING BRAKE SWITCH OR ELSEWHERE
• Inspect the following parts for continuity:
• Is the continuity condition normal?
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Yes
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Go to the next step.
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No
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Replace the malfunctioning part.
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*9
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INSPECT FOR SHORT TO GROUND IN WIRING HARNESS BETWEEN INSTRUMENT CLUSTER AND ELECTRIC PARKING BRAKE SWITCH
• Inspect for short to ground in the following circuit:
• Is the short to ground detected?
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Yes
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Repair or replace the wiring harness for a possible short to ground.
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No
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Retrieve the instrument cluster DTC using the M-MDS.
If the DTC remains:
• Go to the applicable DTC inspection.
If the DTC does not remain:
• Replace the instrument cluster.
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10
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INSPECT DSC HU/CM POWER SUPPLY FUSE
• Inspect the DSC HU/CM ignition power supply fuse.
• Is the fuse normal?
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Yes
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Go to the next step.
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No
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Inspect the blown fuse’s circuit for short to ground.
Repair or replace the wiring harness for a possible short to ground as necessary.
Install appropriate amperage fuse.
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*11
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VERIFY WHETHER MALFUNCTION IS IN WIRING HARNESS (BETWEEN DSC HU/CM POWER SUPPLY AND DSC HU/CM FOR CONTINUITY) OR ELSEWHERE
• Switch the ignition ON.
• Measure the voltage at the DSC HU/CM terminal AH (wiring harness-side).
• Is the voltage approx. 12 V?
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Yes
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Go to the next step.
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No
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Refer to the wiring diagram and verify whether or not there is a common connector between DSC HU/CM terminal AH (wiring harness-side) and IG1 relay No.1 terminal C.
If there is a common connector:
• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
• Repair or replace the malfunctioning part.
If there is no common connector:
• Repair or replace the wiring harness which has an open circuit.
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*12
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VERIFY WHETHER MALFUNCTION IS IN WIRING HARNESS (BETWEEN DSC HU/CM AND GROUND FOR CONTINUITY) OR ELSEWHERE
• Switch the ignition off.
• Disconnect the DSC HU/CM connector.
• Inspect for continuity between DSC HU/CM terminal B (wiring harness-side) and body ground.
• Is there continuity?
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Yes
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Replace the DSC HU/CM. (open circuit in the DSC HU/CM)
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No
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Repair or replace the wiring harness for a possible open circuit and poor contact in ground point.
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