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Home >> Mazda >> 2017 >> CX-5 Grand Select, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 31 (On-Board Diagnostic - Blind Spot Monitoring System) >> DTC U0401-68: Error Signal Received From Pcm >> Diagnostic Procedure

Diagnostic Procedure

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Description Error signal received from PCM
Detection condition 
  • Blind spot monitoring (BSM) control module receives the error signal from the PCM for 1 s or more  .
Fail-safe 
  • Blind spot monitoring (BSM) system is stopped.
Possible cause 
  • DTCs are stored in the PCM.
  • PCM malfunction
  • Blind spot monitoring (BSM) control module malfunction
System wiring diagram  Not applicable
Step Inspection Action
1 VERIFY PCM DTCs  Yes Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
(See DTC TABLE [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .)
No Go to the next step.
2 VERIFY IF MALFUNCTIONING LOCATION IS PCM DEPENDING ON REPEATABILITY  Yes Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .)
No Go to Step 4.
3 VERIFY THAT REPAIRS HAVE BEEN COMPLETED  Yes Replace the blind spot monitoring (BSM) control module, then go to the next step.
(See BLIND SPOT MONITORING (BSM) CONTROL MODULE 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 [BLIND SPOT MONITORING (BSM) SYSTEM] .)
No DTC troubleshooting completed.