DTC

U0338:00, U0515:00

Abnormal signal from start stop unit

DETECTION CONDITION

• The DSC HU/CM received error signals from the start stop unit with the ignition switched ON (engine off or on).

FAIL-SAFE FUNCTION

• Does not illuminate each warning/indicator light (Mazda Radar Cruise Control (MRCC) warning light flashes).

• Inhibits the Mazda Radar Cruise Control (MRCC) control.

POSSIBLE CAUSE

• Start stop unit malfunction

• Cruise control switch malfunction

• PCM malfunction

SYSTEM WIRING DIAGRAM

Not applicable

STEP

INSPECTION

ACTION

1

• Switch the ignition to off.

• Verify DTCs for the start stop unit using the M-MDS.

  (See DTC INSPECTION [START STOP UNIT].)

• Is the DTC displayed?

Yes

Go to applicable DTC inspection.

(See DTC TABLE [START STOP UNIT].)

No

Go to the next step.

2

• Inspect the cruise control switch.

  (See CRUISE CONTROL SWITCH INSPECTION [MAZDA RADAR CRUISE CONTROL (MRCC) SYSTEM].)

• Is the cruise control normal?

Yes

Go to the next step.

No

Replace the cruise control switch, then go to the next step.

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

3

• Switch the ignition to off.

• Verify DTCs for the PCM using the M-MDS.

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

• Is the DTC displayed?

Yes

Go to applicable DTC inspection.

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

No

Go to the next step.

4

• Clear DTC for the DSC HU/CM using the M-MDS.

  (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 start stop unit, then go to the next step.

(See START STOP UNIT REMOVAL/INSTALLATION.)

No

Go to the next step.

5

• Are any other DTCs displayed?

Yes

Repair the malfunctioning part according to the applicable DTC troubleshooting.

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

No

DTC troubleshooting completed.