DTC C1288, C1290, C1440, C1730, C1954


DTC	C1288, C1290, C1440, C1730, C1954		Brake fluid pressure sensor
DETECTION CONDITION		• C1288 - The pressure from the brake fluid pressure sensor when the system starts up is not within specification. • C1290 - The pressure from the brake fluid pressure sensor when not braking exceeds specification. • C1440 - The difference between the estimated brake fluid pressure response calculated by each sensor and the brake fluid pressure response from the brake fluid pressure sensor is not within specification. • C1730 - The voltage to the brake fluid pressure sensor is not within specification. • C1954 - The output voltage from the brake fluid pressure sensor is not within specification.
POSSIBLE CAUSE		• Open or short circuit in the wiring harness between DSC HU/CM terminal B and brake fluid pressure sensor terminal B • Open or short circuit in the wiring harness between DSC HU/CM terminal C and brake fluid pressure sensor terminal C • Open circuit in the wiring harness between DSC HU/CM terminal E and brake fluid pressure sensor terminal A • Malfunction in the brake fluid pressure sensor • Poor connection at connectors (female terminal) • Open circuit in the wiring harness between brake light noise filter and brake switch • Open circuit in the wiring harness between brake light noise filter and DSC HU/CM • Open circuit in the wiring harness between brake light noise filter and STOP 15 A fuse • Brake switch malfunction • STOP 15 A fuse malfunction • Brake light noise filter malfunction


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 depressed: On - Brake pedal released: Off • Does the "BOO_ABS" PID change normally?	Yes	Go to Step 6.
1		No	Go to the next step.
2	INSPECT STOP LIGHT FUSE CONDITION • Turn the ignition switch off. • Inspect the STOP 15 A fuse. • Is the STOP 15 A fuse normal?	Yes	Go to the next step.
2		No	Replace the fuse, then go to Step 11.
3	INSPECT BRAKE SWITCH • Inspect the brake switch. (See BRAKE SWITCH INSPECTION.) • Is the brake switch normal?	Yes	Go to the next step.
3		No	Replace the brake switch, then go to Step 11. (See BRAKE PEDAL REMOVAL/INSTALLATION.)
4	INSPECT BRAKE LIGHT NOISE FILTER • Inspect the brake light noise filter. (See Brake Light Noise Filter Inspection.) • Is the brake light noise filter normal?	Yes	Go to the next step.
4		No	Replace the wiring harness (including the brake light noise filter), then go to Step 11. Note • The brake light noise filter is integrated with the wiring harness and cannot be replaced individually. Therefore, if there is a malfunction of the brake light noise filter, replace the wiring harness.
5	INSPECT FOR OPEN CIRCUIT IN WIRING HARNESS BETWEEN DSC HU/CM AND STOP LIGHT FUSE • Disconnect the DSC HU/CM, brake switch, and brake light noise filter connectors. • Inspect the vehicle wiring harness-side connectors for continuity between the following terminals: - STOP 15 A fuse-brake light noise filter terminal A - Brake light noise filter terminal C-brake switch terminal B - Brake switch terminal D-brake light noise filter terminal D - Brake light noise filter terminal B-DSC HU/CM terminal AD • Is there continuity?	Yes	Go to the next step.
5		No	Repair or replace the wiring harness for open circuit between brake switch, brake light noise filter and DSC HU/CM, then go to Step 11.
6	INSPECT BRAKE FLUID PRESSURE SENSOR POWER SUPPLY FOR OPEN CIRCUIT • Turn the ignition switch to the ON position (engine off). • Measure the voltage between brake fluid pressure sensor terminal C (harness-side) and ground. • Is the voltage 4.75-5.25 V?	Yes	Go to the next step.
6		No	Repair or replace the wiring harness for open circuit between brake fluid pressure sensor terminal C and DSC HU/CM terminal C, then go to Step 11.
7	INSPECT BRAKE FLUID PRESSURE SENSOR GROUND FOR OPEN CIRCUIT • Turn the ignition switch off. • Disconnect DSC HU/CM and brake fluid pressure sensor connectors. • Inspect for continuity between DSC HU/CM terminal E (harness-side) and brake fluid pressure sensor terminal A (harness-side). • Is there continuity?	Yes	Go to the next step.
7		No	Repair or replace the wiring harness for open circuit between DSC HU/CM terminal E and brake fluid pressure sensor terminal A, then go to Step 11.
8	INSPECT BRAKE FLUID PRESSURE SENSOR SIGNAL FOR OPEN CIRCUIT • Inspect for continuity between DSC HU/CM terminal B (harness-side) and brake fluid pressure sensor terminal B (harness-side). • Is there continuity?	Yes	Go to the next step.
8		No	Repair or replace the wiring harness for open circuit between DSC HU/CM terminal B and brake fluid pressure sensor terminal B, then go to Step 11.
9	INSPECT BRAKE FLUID PRESSURE SENSOR SIGNAL FOR SHORT TO GROUND • Turn the ignition switch off. • Inspect for continuity between DSC HU/CM terminal B (harness-side) and ground. • Is there continuity?	Yes	Repair or replace the wiring harness for short to ground between DSC HU/CM terminal B and brake fluid pressure sensor terminal B, then go to Step 11.
9		No	Go to the next step.
10	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.
10		No	Replace the DSC HU/CM, then go to the next step. (See DSC HU/CM REMOVAL/INSTALLATION.)
11	VERIFY DTC TROUBLESHOOTING COMPLETED • Clear the DTC from the memory. (See Clearing DTCs Procedures.) • Are the same DTCs present?	Yes	Replace the DSC HU/CM, then go to the next step. (See DSC HU/CM REMOVAL/INSTALLATION.)
11		No	Go to the next step.
12	VERIFY AFTER REPAIR PROCEDURE • Are any other DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC Table.)
12		No	DTC troubleshooting completed.

Brake Light Noise Filter Inspection

1. Verify the resistance and continuity between the brake light noise filter terminals.