DTC U1A4B:97 [REAR VEHICLE MONITORING SYSTEM]

id0902z2885100

Description

Radar sensor sensitivity temporarily decreases depending on various external and environmental factors (Rear vehicle monitoring control module (RH))

Detection condition

•  Radar sensor sensitivity in rear vehicle monitoring control module (RH) decreases for 5 s or more.

Fail-safe function

•  Inhibits the rear vehicle monitoring system.

Possible cause

•  Rear bumper dirt or foreign material (reflective object) is adhered.

•  Dirt or foreign material (reflective object) on rear vehicle monitoring control module (RH)

•  Concavity and convexity on the surface of the repaired rear bumper

•  Rear vehicle monitoring control module (RH) malfunction

System wiring diagram

Not applicable

Description	Radar sensor sensitivity temporarily decreases depending on various external and environmental factors (Rear vehicle monitoring control module (RH))
Detection condition	• Radar sensor sensitivity in rear vehicle monitoring control module (RH) decreases for 5 s or more.
Fail-safe function	• Inhibits the rear vehicle monitoring system.
Possible cause	• Rear bumper dirt or foreign material (reflective object) is adhered. • Dirt or foreign material (reflective object) on rear vehicle monitoring control module (RH) • Concavity and convexity on the surface of the repaired rear bumper • Rear vehicle monitoring control module (RH) malfunction
System wiring diagram	Not applicable

Diagnostic Procedure

Step	Inspection		Action
1	INSPECT REAR BUMPER SURFACE • Visually inspect the rear bumper surface for the following: ― Dirt ― Adhered foreign material (reflective object) • Is the rear bumper normal?	Yes	Go to the next step.
1		No	Remove dirt or foreign material (reflective object), then go to Step 4.
2	INSPECT AREA AROUND REAR VEHICLE MONITORING CONTROL MODULE (RH) • Visually inspect the area around the rear vehicle monitoring control module (RH) for the following: ― Dirt ― Adhered foreign material (reflective object) • Is the area around the rear vehicle monitoring control module (RH) normal?	Yes	Go to the next step.
2		No	Remove dirt or foreign material (reflective object), then go to Step 4.
3	VERIFY REAR BUMPER REPAIR HISTORY • Verify if the rear bumper had been repaired or repainted before. • Is there a problem with the repair? (Is the paint Mazda genuine?)	Yes	Go to the next step.
3		No	Replace the rear bumper, then go to the next step. (See REAR BUMPER REMOVAL/INSTALLATION.)
4	VERIFY THAT REPAIRS HAVE BEEN COMPLETED • Clear the DTC for the rear vehicle monitoring control module using the M-MDS. (See CLEARING DTC [REAR VEHICLE MONITORING SYSTEM].) • Drive the vehicle at a vehicle speed of 40 km/h {25 mph} or more for 5 s or more. • Retrieve the rear vehicle monitoring control module DTCs using the M-MDS. (See DTC INSPECTION [REAR VEHICLE MONITORING SYSTEM].) • Is the same DTC displayed?	Yes	Repeat the inspection from Step 1. • If the malfunction recurs, replace the rear vehicle monitoring control module (RH). (See REAR VEHICLE MONITORING CONTROL MODULE REMOVAL/INSTALLATION.) Go to the next step.
4		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. (See DTC TABLE [REAR VEHICLE MONITORING SYSTEM].)
5		No	DTC troubleshooting completed.