DTC U0301:09 [RADAR UNIT]


id1502a6018800

Description

Error signal received from PCM

Detection condition
•  There is an error in the following signals sent from the PCM.
?  Brake switch signal
?  Cruise control system control signal
Fail-safe
•  Inhibits the Mazda radar cruise control (MRCC) system control
•  Inhibits the smart brake support (SBS) system control (Radar unit type B (VIN serial No. 200001-))
•  Inhibits the distance recognition support system (DRSS) control (Radar unit type B (VIN serial No. 200001-))
Possible cause
•  DTCs are stored in the PCM.
•  DTCs are stored in the DSC HU/CM.
?  DSC HU/CM malfunction
•  PCM 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.
•  Are any other DTCs displayed?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
No
Go to the next step.
2
VERIFY DSC HU/CM DTCs
•  Retrieve the DSC HU/CM DTCs using the M-MDS.
•  Are any other DTCs displayed?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
No
Go to the next step.
3
VERIFY IF MALFUNCTIONING LOCATION IS PCM DEPENDING ON REPEATABILITY
•  Clear the DTC for the radar unit using the M-MDS.
•  Retrieve the radar unit DTCs using the M-MDS.
•  Is the same DTC displayed?
Yes
Replace the PCM, then go to the next step.
No
Go to the next step.
4
VERIFY THAT REPAIRS HAVE BEEN COMPLETED
•  Clear the DTC for the radar unit using the M-MDS.
•  Retrieve the radar unit DTCs using the M-MDS.
•  Is the same DTC displayed?
Yes
Replace the radar unit, then go to the next step.
No
Go to the next step.
5
VERIFY IF OTHER DTCs DISPLAYED
•  Are any other DTCs displayed?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
No
DTC troubleshooting completed.