DTC

U0320:00, U0420:00, U0420:64

Abnormal message from EPS CM

DETECTION CONDITION

• U0320:00, U0420:00

• The steering angle sensor detects signal modulation or steering angle that exceeds specification.

• U0420:64

• The signal from the steering angle sensor remains unchanged when the steering angle is turned to the right and left.

FAIL-SAFE FUNCTION

• Illuminates the TCS/DSC indicator light and master warning light*¹.

• Inhibits the TCS, DSC, Mazda Radar Cruise Control (MRCC)*², and Smart City Brake Support (SCBS)*² controls.

*¹: Vehicles with Smart City Brake Support (SCBS).

*²: If equipped.

POSSIBLE CAUSE

• EPS CM malfunction

SYSTEM WIRING DIAGRAM

Not applicable

STEP

INSPECTION

ACTION

1

• Switch the ignition off.

• Using the M-MDS, perform the DTC inspection for the EPS CM.

  (See ELECTRIC POWER STEERING (EPS) ON-BOARD DIAGNOSIS.)

• Are any DTCs detected?

Yes

Go to applicable DTC inspection.

(See ELECTRIC POWER STEERING (EPS) ON-BOARD DIAGNOSIS.)

No

Go to the next step.

2

• Clear the DTCs from the memory.

  (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 EPS CM, then go to the next step.

(See STEERING WHEEL AND COLUMN REMOVAL/INSTALLATION.)

No

Go to the next step.

3

• Are any other DTCs output?

Yes

Go to the applicable DTC inspection.

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

No

DTC troubleshooting completed.