VEHICLE SPEED DECREASES UNINTENTIONALLY [MAZDA RADAR CRUISE CONTROL (MRCC) SYSTEM]

id1503d3005700

Note

•  Due to environmental effects, the system behavior may differ from the driver’s intentions even though the vehicle has no malfunction. To perform symptom troubleshooting, an understanding of the applicable system from the new vehicle instruction is required. For details on the control conditions of the system, refer to the [MAZDA RADAR CRUISE CONTROL (MRCC) SYSTEM] operation in the service highlights/technical guide.

Outline

Description	•  Vehicle speed decreases unintentionally.
Possible cause	•  Poor installation, damage, deformity, or looseness of front radar sensor, front bumper (including moderate impacts) •  Forward sensing camera (FSC) aiming not completed •  Front radar sensor aiming not completed •  Forward sensing camera (FSC) malfunction •  Front radar sensor malfunction

Diagnostic Procedure

Step	Inspection	Results	Action
1	VERIFY ALL SYSTEM DTCs •  Perform the DTC inspection. (See DTC INSPECTION.) •  Are any DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting.
		No	Go to the next step.
2	VERIFY FRONT RADAR SENSOR INSTALLATION CONDITION •  When a malfunction occurred, verify if the vehicle or environment corresponds to any of the following. ―  Poor installation, damage, deformity, or looseness of front radar sensor, front bumper (including moderate impacts) •  Did the vehicle or environment correspond to any of the above conditions?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification.
		No	Go to the next step.
3	PERFORM FORWARD SENSING CAMERA (FSC) AIMING •  Perform the forward sensing camera (FSC) aiming. (See FORWARD SENSING CAMERA (FSC) AIMING.)	-	Go to the next step.
4	PERFORM FRONT RADAR SENSOR AIMING •  Perform the front radar sensor aiming. (See FRONT RADAR SENSOR AIMING.)	-	Go to the next step.
Repair completion verification	VERIFY THAT VEHICLE IS REPAIRED •  Install/connect the part removed/disconnected during the troubleshooting procedure. •  Has the malfunction symptom been eliminated?	Yes	Complete the symptom troubleshooting. (Explain contents of repair to customer)
		No	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].) If the CAN communication is normal, perform the diagnosis from Step 1. •  If the malfunction is not resolved, replace the front radar sensor. (See FRONT RADAR SENSOR REMOVAL/INSTALLATION.)