DTC B1484, C1954 [DYNAMIC STABILITY CONTROL (DSC)]

id0402b2800500

DTC
B1484, C1954
Brake switch system
DETECTION CONDITION
•  B1484
―  Open circuit is detected in wiring harness between DSC HU/CM—brake switch (Voltage at the DSC HU/CM terminal N is more than 40% and less than 67% of the voltage at the DSC HU/CM terminal J for 0.5 s continuously.).
•  C1954
―  Brake switch ON signal is input even though signal from brake fluid pressure sensor is lower than specified value (While vehicle is driven at a speed of 10.8 km/h {6.7 mph} or more, brake switch is continuously ON for 60 s with accelerator pedal ON and brake fluid pressure 500 kPa {5.10 kgf/cm2, 72.5 psi}or lower, not operated).
―  Brake fluid pressure sensor signal value is continuously more than 1,000 kPa {10.20 kgf/cm2, 145.0 psi} for 1 s with brake switch signal OFF.
POSSIBLE CAUSE
•  STOP 10A fuse malfunction
•  Brake switch malfunction
•  Open circuit or short to ground in the wiring harness between the DSC HU/CM terminal N and the brake switch terminal D
•  Brake fluid pressure sensor malfunction in DSC HU/CM

Diagnostic procedure

STEP

INSPECTION

ACTION
1
INSPECT BRAKE PEDAL POSITION SIGNAL INPUT TO DSC HU/CM USING M-MDS
•  Connect the M-MDS to the DLC-2.
•  Select the “BOO_ABS” PID and verify that the display is switched as follows according to the brake pedal condition:
―  Brake pedal released: Off
―  Brake pedal depressed: On
•  Does the “BOO_ABS” PID change normally?
Yes
Go to Step 6.
No
Go to the next step.
2
INSPECT STOP LIGHT FUSE CONDITION
•  Turn the ignition switch to the LOCK position.
•  Inspect the STOP 10A fuse.
•  Is the STOP 10A fuse normal?
Yes
Go to the next step.
No
Replace the fuse, then go to Step 6.
3
INSPECT BRAKE SWITCH
•  Inspect the brake switch.
•  Is the brake switch normal?
Yes
Go to the next step.
No
Replace the brake switch, then go to Step 6.
(See BRAKE PEDAL REMOVAL/INSTALLATION.)
4
INSPECT FOR OPEN CIRCUIT IN WIRING HARNESS BETWEEN DSC HU/CM AND STOP LIGHT FUSE
•  Disconnect the DSC HU/CM and brake switch connectors.
•  Inspect the vehicle wiring harness-side connectors for continuity between the following terminals:
―  STOP 10A fuse—brake switch terminal B
―  Brake switch terminal D—DSC HU/CM terminal N
•  Is there continuity?
Yes
Go to the next step.
No
Repair or replace the wiring harness for open circuit between brake switch and DSC HU/CM, then go to Step 6.
5
INSPECT BRAKE FLUID PRESSURE SENSOR
•  Inspect the brake fluid pressure sensor.
•  Is the brake fluid pressure sensor normal?
Yes
Go to the next step.
No
Replace the DSC HU/CM, then go to the next step.
(See DSC HU/CM REMOVAL/INSTALLATION.)
6
VERIFY DTC TROUBLESHOOTING COMPLETED
•  Make sure to reconnect all disconnected connectors.
•  Clear the DTC from the memory.
•  Start the engine and drive the vehicle at 20 km/h {13 mph} or more for 60 s or more.
•  Are the same DTCs present?
Yes
Repeat the inspection from Step 1.
If the malfunction recurs, replace the DSC HU/CM, then go to the next step.
(See DSC HU/CM REMOVAL/INSTALLATION.)
No
Go to the next step.
7
VERIFY AFTER REPAIR PROCEDURE
•  Are any other DTCs present?
Yes
Go to the applicable DTC inspection.
(See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].)
No
DTC troubleshooting completed.