DTC

C0044:14/C0044:1C/C0044:65/C0044:66/C0044:67

Brake fluid pressure sensor

DETECTION CONDITION

• C0044:14

• With the DSC HU/CM terminal voltage within the normal range, the brake fluid pressure sensor power supply voltage is 4.7 V or less, or 5.3 V or higher for a continuous 1.2 s, or the brake fluid pressure sensor output value is less than the specified value or exceeds the specified value for a continuous 1.2 s.

• C0044:1C

0-point output

• The brake fluid pressure sensor output value is less than the specified value or it exceeds the specified value for a continuous 5 s with the brake switch in the off condition.

Output increase

• The following condition is detected 9 times continuously (One detection period is when ignition is switched from ON to off).

• While the vehicle is traveling at a speed of 7 km/h {4 mph} or more, the deceleration rate calculated from the brake fluid pressure sensor signal value is detected 5 times or more at 1/4 or less than the normal value for a continuous 1 s.

• C0044:65/C0044:67

Sticking

• While the vehicle is traveling at a speed of 7 km/h {4 mph} or more, no fluctuation in the output value at 0.048 MPa {0.49 kgf/cm², 7.0 psi} or higher is detected with the brake fluid pressure sensor output value exceeding specified value.

Sticking during braking

• While the vehicle is traveling at a speed of 40 km/h {25 mph} or more, the amount of fluctuation in the brake fluid pressure sensor value is detected 5 times to be 0.048 MPa {0.49 kgf/cm², 7.0 psi} or less until the vehicle speed reaches 0 km/h {0 mph} and with the brake switch on.

• C0044:66

• While the vehicle is traveling at a speed of 10 km/h {6.2 mph} or more, a brake fluid pressure sensor signal value of 1000 MPa/s or more is detected 7 times or more during a 5 s period.

FAIL-SAFE FUNCTION

• Illuminates the TCS/DSC indicator light, and master warning light*¹.

• Tire pressure monitoring system warning light illuminates after flashes.

• Inhibits the brake assist, TCS, Hill Launch Assist (HLA), vehicle roll prevention function*², DSC, Mazda Radar Cruise Control (MRCC)*², Smart City Brake Support (SCBS)*², and TPMS controls.

*¹: Vehicles with Smart City Brake Support (SCBS).

*²: If equipped.

POSSIBLE CAUSE

• DSC HU/CM malfunction

• Brake fluid pressure sensor malfunction

• Short or open circuit in brake fluid pressure sensor circuit

• Brake switch malfunction

• PCM malfunction

SYSTEM WIRING DIAGRAM

Not applicable

STEP

INSPECTION

ACTION

1

• Switch the ignition ON.

• Measure the voltage between the DSC HU/CM terminal C and body ground when the brake pedal is depressed and released:

• Voltage

  Brake pedal depressed: B+

  Brake pedal released: 1 V or less

• Is the voltage normal?

Yes

Go to Step 5.

No

If it is B+ under any condition, then go to the next step.

If it is 1 V or less under any condition, then go to Step 4.

2

• Disconnect the brake switch connector.

• Measure voltage between the brake switch connector terminal D (vehicle harness-side) and body ground.

• Is the voltage 1 V or less?

Yes

Go to Step 3.

No

Refer to the wiring diagram and verify whether or not there is a common connector between the PCM and brake switch.

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 a short to power supply.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has a short to power supply.

Go to Step 5.

3

• 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 the Step 5.

(See BRAKE PEDAL REMOVAL/INSTALLATION.)

4

• Reconnect all disconnected connectors.

• Using the M-MDS, perform the DTC inspection for the PCM.

  (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5].)

• Are any DTCs detected?

Yes

Go to applicable DTC inspection.

(See DTC TABLE [SKYACTIV-G 2.5].)

No

Go to the next step.

5

• Reconnect all disconnected connectors.

• Clear the DTCs from the memory.

  (See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].)

• Start the engine and drive the vehicle at 40 km/h {25 mph} or more.

• Gradually slow down and stop the vehicle.

• Perform the DSC DTC inspection.

  (See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].)

• 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.

6

• Reconnect all disconnected connectors.

• Clear the DTCs from the memory.

  (See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].)

• Start the engine and drive the vehicle at 20 km/h {12 mph} 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

• Are any other DTCs output?

Yes

Go to the applicable DTC inspection.

(See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].)

No

DTC troubleshooting completed.