Mazda CX-5 Service & Repair Manual: Bsm Indicator Light Flashes While Not Under Bsm Indicator Light Flashing Conditions (No Combination Switch Operation (Turn Signal Switch)) [Blind Spot Monitoring (Bsm)]

Description

BSM indicator light flashes while not under BSM indicator light-flashing conditions (no combination switch operation (turn signal switch)

• The BSM indicator light flashes despite not satisfying the BSM indicator light flashing conditions (vehicle speed above 32 km/h {20 mph} or more, turn signal on, and vehicle in warning zone).

• The BSM indicator light flashes, but the turn signals are off.

Possible Causes

NOTE:

• This malfunction symptom is basically the same as symptom “BSM indicator light while not under BSM indicator light-illumination conditions”.

• BSM control module recognizes a vehicle as being inside the warning zone when it is actually outside of it.

• Radar (BSM control module integrated) is emitted outside of warning zone (deviates from warning zone)

• Damage, deformity or looseness to installation bracket or vehicle frame (including moderate impacts).

• Malfunction in steering angle signal (communication error between rear body control module (RBCM) and BSM control module, or EPS control module malfunction).

• Problem with rear bumper such as soiling to radar emitting/receiving area, application of stickers (including transparent types), repairs using putty application.

• After-market electrical parts interfere with BSM system

• BSM does not recognize vehicle speed correctly (BSM control module mistakenly recognizes vehicle speed as being above 32 km/h {20 mph} or more)

• PCM communication error with BSM control module

• Malfunction in ABS wheel speed sensor related parts

• BSM control module mistakenly recognizes that turn signals have been operated

• Short to ground circuit in wiring harness between combination switch (turn signal switch) and rear body control module (RBCM)

• Communication error between rear body control module (RBCM) and BSM control module

• BSM control module malfunction

Step

Inspection

Result

Action

1

VERIFY MALFUNCTION SYMPTOM

• BSM indicator light illuminates while under light-off conditions.

Yes

Go to the symptom troubleshooting procedure, “ BSM indicator light illuminates while not under BSM indicator light-off conditions”.

(See BSM INDICATOR LIGHT ILLUMINATES WHILE NOT UNDER LIGHT-ILLUMINATION CONDITIONS [BLIND SPOT MONITORING (BSM)].)

No

Go to the next step.

2

INSPECT IF MALFUNCTION IS IN REAR BODY CONTROL MODULE (RBCM) INPUT SIGNAL OR BSM

• Monitor the following PIDs on the suspected side of the BSM control module using the M-MDS.

  (See PID/DATA MONITOR TABLE [BLIND SPOT MONITORING (BSM)].)

• TURN_SW_L

• TURN_SW_R

• Are the monitoring values normal?

Yes

Replace the BSM control module.

(See BLIND SPOT MONITORING (BSM) CONTROL MODULE REMOVAL/INSTALLATION.)

No

Retrieve DTCs from the start stop unit, instrument cluster, and BSM control module using the M-MDS.

(See DTC INSPECTION [START STOP UNIT].)

(See DTC INSPECTION [INSTRUMENT CLUSTER].)

(See DTC INSPECTION [BLIND SPOT MONITORING (BSM)].)