System malfunction location

Brake fluid level signal error

Detection condition

• The front body control module (FBCM) continues the detected condition in which the brake fluid level is less than MIN for the specified period or more.

Fail-safe

• Inhibits the Mazda radar cruise control (MRCC) system control

• Inhibits the forward obstruction warning (FOW) system control

Possible cause

• Insufficient brake fluid level

• Malfunction in circuit between brake fluid level sensor and front body control module (FBCM) and front body control module (FCBM)

• Signal error in circuit between front body control module (FBCM) and vehicle control module (V/C-module)

System wiring diagram

• Not applicable

Step

Inspection

Action

1

• Inspect the brake fluid level.

  (See BRAKE FLUID INSPECTION.)

• Is the brake fluid level normal?

Yes

Go to the next step.

No

Add genuine brake fluid, then go to Step 4.

2

• Perform the vehicle control module (V/C-module) DTC inspection using the M-MDS.

  (See DTC INSPECTION [VEHICLE CONTROL MODULE (V/C-MODULE)].)

• Is DTC U0422:00 output?

Yes

Go to the applicable DTC inspection.

(See DTC U0422:00 [VEHICLE CONTROL MODULE (V/C-MODULE)].)

Then go to Step 4.

No

Go to the next step.

3

• Perform the front body control module (FBCM) DTC inspection using the M-MDS.

  (See DTC INSPECTION [FRONT BODY CONTROL MODULE (FBCM)].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [FRONT BODY CONTROL MODULE (FBCM)].)

Then go to the next step.

No

Go to the next step.

4

• Clear vehicle control module (V/C-module) DTCs using the M-MDS.

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

• Switch the ignition ON (engine on).

• Perform the vehicle control module (V/C-module) DTC inspection using the M-MDS.

  (See DTC INSPECTION [VEHICLE CONTROL MODULE (V/C-MODULE)].)

• Is the same DTC present?

Yes

Repeat the inspection from Step 1.

• If the malfunction does not recur, go to the next step.

• If the malfunction recurs, replace the vehicle control module (V/C-module).

  (See VEHICLE CONTROL MODULE (V/C-MODULE) REMOVAL/INSTALLATION [MAZDA RADAR CRUISE CONTROL (MRCC) SYSTEM].)

Go to the next step.

No

Go to the next step.

5

• Verify other DTCs displayed.

• Are any other DTCs output?

Yes

Perform the corresponding DTC inspection.

No

DTC troubleshooting completed.