System malfunction location

Radar sensor is outside of operation range (ignition power supply, internal temperature)

Detection condition

• Radar sensor power supply voltage is other than 9.5—15.5 V.

• Temperature in radar sensor exceeds specification.

Fail-safe

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

• Inhibits the forward obstruction warning (FOW) system control

Possible cause

• Generator system malfunction

• C/U IG1 15 A fuse malfunction

• Battery malfunction

• Open circuit or short to ground in wiring harness between battery positive terminal and radar sensor

• Radar sensor malfunction

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

Step

Inspection

Action

1

• Perform the PCM DTC inspection using the M-MDS.

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

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

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

Then go to Step 6.

No

Go to the next step.

2

• Switch the ignition off (LOCK).

• Disconnect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5].)

• Remove the C/U IG1 15 A fuse.

• Is the fuse normal?

Yes

Install the C/U IG1 15 A fuse, then go to the next step.

No

Replace the C/U IG1 15 A fuse, then go to Step 6.

3

• Inspect the battery.

  (See BATTERY INSPECTION [SKYACTIV-G 2.5].)

• Is the battery normal?

Yes

Go to the next step.

No

Replace/charge the battery, then go to Step 6.

(See BATTERY REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

(See BATTERY RECHARGING [SKYACTIV-G 2.5].)

4

• Remove the front bumper.

  (See FRONT BUMPER REMOVAL/INSTALLATION.)

• Disconnect the radar sensor connector.

• Connect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5].)

• Switch the ignition ON (engine off or on).

• Measure the voltage of radar sensor terminal E (wiring harness-side).

NOTE:

• Measure the voltage while shaking the wiring harness between the radar sensor and IG1 relay.

• Is the voltage between approx. 9.5—15.5 V?

Yes

Go to the next step.

No

Refer to the wiring diagram and verify whether or not there is a common connector between radar sensor terminal E and IG1 relay.

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit or short to ground.

• Repair or replace the malfunctioning part.

• Repair or replace the wiring harness which has an open circuit or short to ground.

Go to Step 6.

5

• Connect the radar sensor connector.

• Connect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5].)

• 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).

• 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

Replace the 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.

6

• 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).

• 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.

7

• Verify other DTCs displayed.

• Are any other DTCs output?

Yes

Perform the corresponding DTC inspection.

No

DTC troubleshooting completed.