System malfunction location

Error signal received from DSC HU/CM

Detection condition

• Communication error between DSC HU/CM and vehicle control module (V/C-module)

Fail-safe

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

• Inhibits the forward obstruction warning (FOW) system control

Possible cause

• DSC HU/CM malfunction

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

System wiring diagram

• Not applicable

Step

Inspection

Action

1

• Perform the DSC HU/CM DTC inspection using the M-MDS.

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

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

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

Then go to Step 3.

No

Go to the next step.

2

• 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 DSC HU/CM, then go to the next step.

(See DSC HU/CM REMOVAL/INSTALLATION.)

No

Go to the next step.

3

• 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.

4

• Verify other DTCs displayed.

• Are any other DTCs output?

Yes

Perform the corresponding DTC inspection.

No

DTC troubleshooting completed.