DTC U0301:09 [RADAR UNIT]

id1502a6018800

Description

Error signal received from PCM

Detection condition

•  Radar unit receives the following signals from the PCM.

―  Brake switch error signal

―  Cruise control switch error signal

―  PCM internal malfunction signal

―  Cruise control error signal

―  Engine speed error signal

―  Accelerator opening angle error signal

Fail-safe

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

Possible cause

•  DTCs are stored in the PCM.

―  PCM malfunction

•  DTCs are stored in the ABS HU/CM or DSC HU/CM.

―  ABS HU/CM or DSC HU/CM malfunction

•  Radar unit malfunction

System wiring diagram

Not applicable

Description	Error signal received from PCM
Detection condition	• Radar unit receives the following signals from the PCM. ― Brake switch error signal ― Cruise control switch error signal ― PCM internal malfunction signal ― Cruise control error signal ― Engine speed error signal ― Accelerator opening angle error signal
Fail-safe	• Inhibits the mazda radar cruise control (MRCC) system control
Possible cause	• DTCs are stored in the PCM. ― PCM malfunction • DTCs are stored in the ABS HU/CM or DSC HU/CM. ― ABS HU/CM or DSC HU/CM malfunction • Radar unit malfunction
System wiring diagram	Not applicable

Diagnostic Procedure

Step

Inspection

Action

1

VERIFY PCM DTCs

•  Retrieve the PCM DTCs using the M-MDS.
(See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5)].)

(See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-D 1.5)].)

(See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-D 2.2)].)

(See ON-BOARD DIAGNOSTIC TEST [MZR 1.6].)

•  Are any DTCs displayed?

Yes

Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.

(See DTC TABLE [PCM (SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5)].)

(See DTC TABLE [PCM (SKYACTIV-D 1.5)].)

(See DTC TABLE [PCM (SKYACTIV-D 2.2)].)

(See DTC TABLE [MZR 1.6].)

No

Go to the next step.

2

VERIFY ABS HU/CM OR DSC HU/CM DTCs

•  Retrieve the ABS HU/CM or DSC HU/CM DTCs using the M-MDS.
(See ON-BOARD DIAGNOSIS [ANTILOCK BRAKE SYSTEM (ABS)].)

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

•  Are any DTCs displayed?

Yes

Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.

(See ON-BOARD DIAGNOSIS [ANTILOCK BRAKE SYSTEM (ABS)].)

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

No

Go to the next step.

3

VERIFY THAT REPAIRS HAVE BEEN COMPLETED

•  Clear the DTC for the radar unit using the M-MDS.
(See CLEARING DTC [RADAR UNIT].)

•  Retrieve the radar unit DTCs using the M-MDS.
(See DTC INSPECTION [RADAR UNIT].)

•  Is the same DTC displayed?

Yes

Replace the radar unit, then go to the next step.

(See RADAR UNIT REMOVAL/INSTALLATION.)

No

Go to the next step.

4

VERIFY IF OTHER DTCs DISPLAYED

•  Are any other DTCs displayed?

Yes

Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.

(See DTC TABLE [RADAR UNIT].)

No

DTC troubleshooting completed.

Step	Inspection		Action
1	VERIFY PCM DTCs • Retrieve the PCM DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5)].) (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-D 1.5)].) (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-D 2.2)].) (See ON-BOARD DIAGNOSTIC TEST [MZR 1.6].) • Are any DTCs displayed?	Yes	Repair or replace the malfunctioning part according to the applicable DTC troubleshooting. (See DTC TABLE [PCM (SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5)].) (See DTC TABLE [PCM (SKYACTIV-D 1.5)].) (See DTC TABLE [PCM (SKYACTIV-D 2.2)].) (See DTC TABLE [MZR 1.6].)
1		No	Go to the next step.
2	VERIFY ABS HU/CM OR DSC HU/CM DTCs • Retrieve the ABS HU/CM or DSC HU/CM DTCs using the M-MDS. (See ON-BOARD DIAGNOSIS [ANTILOCK BRAKE SYSTEM (ABS)].) (See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].) • Are any DTCs displayed?	Yes	Repair or replace the malfunctioning part according to the applicable DTC troubleshooting. (See ON-BOARD DIAGNOSIS [ANTILOCK BRAKE SYSTEM (ABS)].) (See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].)
2		No	Go to the next step.
3	VERIFY THAT REPAIRS HAVE BEEN COMPLETED • Clear the DTC for the radar unit using the M-MDS. (See CLEARING DTC [RADAR UNIT].) • Retrieve the radar unit DTCs using the M-MDS. (See DTC INSPECTION [RADAR UNIT].) • Is the same DTC displayed?	Yes	Replace the radar unit, then go to the next step. (See RADAR UNIT REMOVAL/INSTALLATION.)
3		No	Go to the next step.
4	VERIFY IF OTHER DTCs DISPLAYED • Are any other DTCs displayed?	Yes	Repair or replace the malfunctioning part according to the applicable DTC troubleshooting. (See DTC TABLE [RADAR UNIT].)
4		No	DTC troubleshooting completed.