System malfunction location

Radar sensor sensitivity lowered

Detection condition

• Radar sensor sensitivity decreases.

Fail-safe

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

• Inhibits the forward obstruction warning (FOW) system control

Possible cause

• Dirt, snow, or thick moisture film (such as condensation) is adhering to surface of radar sensor or radiator grille ornament

• Reflective object is adhering to radar sensor surface and the area around it

• Radar sensor malfunction

• Vehicle control module (V/C-module) malfunction

System wiring diagram

• Not applicable

Step

Inspection

Action

1

• Visually inspect the surface of the radiator grille ornament.

• Under the following conditions?

• Dirt is adhering to radiator grille ornament.

• Foreign matter (reflective object) is adhering to radiator grille ornament

Yes

Return the surfaces of the radiator grille ornament to their normal condition, then go to Step 4.

No

Go to the next step.

2

• Remove front bumper.

  (See FRONT BUMPER REMOVAL/INSTALLATION.)

• Visually inspect the surface of the radar sensor.

• Under the following conditions?

• Dirt is adhering to radar sensor

• Foreign matter (reflective object) is adhering to radar sensor

Yes

Return the radar sensor to their normal condition, then go to Step 4.

No

Go to the next step.

3

• Is the message indicating “FOW, MRCC Radar blocked” displayed in the LCD in the instrument cluster?

Yes

Switch the ignition off (LOCK), leave it for 30 min to cool down the radar sensor, switch the ignition ON (engine off or on) again, and verify the message indicating “FOW, MRCC Radar blocked” in the LCD.

“FOW, MRCC Radar blocked” is not displayed

• Go to the next step.

“FOW, MRCC Radar blocked” is displayed

• Replace radar sensor, then go to the next step.

  (See RADAR SENSOR REMOVAL/INSTALLATION [MAZDA RADAR CRUISE CONTROL (MRCC) SYSTEM].)

No

Go to the next step.

4

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

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

• Switch the ignition ON (engine on).

• Drive the vehicle at 40 km/h (25 mph) or more for 3 min or more.

• 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.