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. (See BRAKE SWITCH INSPECTION.) • 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. (See BRAKE FLUID PRESSURE SENSOR INSPECTION.) • 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. (See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].) • 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? (See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].) | 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? (See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].) | Yes | Go to the applicable DTC inspection. (See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].)
No | DTC troubleshooting completed.