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Home >> Mazda >> 2017 >> MX-5 Miata Club, Automatic Trans >> Repair and Diagnosis >> Accessories & Equipment >> Anti-Theft Systems >> On-Board Diagnostic - Retractable Fastback Control Module >> DTC B1DA9-2B; Retractable Fastback Switch Circuit Malfunction >> Diagnostic Procedure
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Diagnostic Procedure

Step Inspection Action
1 VERIFY OTHER RETRACTABLE FASTBACK CONTROL MODULE DTCs
Yes Replace the retractable fastback control module, then go to Step 4.
(See RETRACTABLE FASTBACK CONTROL MODULE REMOVAL/INSTALLATION ).
No Go to the next step.
2 INDICATOR UNIT CIRCUIT FOR SHORT TO GROUND
  • Switch the ignition off.
  • Disconnect the negative battery cable.

    (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION ).

  • Disconnect the retractable fastback control module and indicator unit connectors.
  • Inspect for continuity between the following terminals (wiring harness-side) and body ground:
    • Indicator unit terminal I
  • Is there continuity?
Yes Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
  • Retractable fastback control module terminal 1J and indicator unit terminal I If there is a common connector:
  • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
  • Repair or replace the malfunctioning part.

    If there is no common connector:

  • Repair or replace the wiring harness which has a short to ground.

Go to Step 4.
No Go to the next step.
3 INDICATOR UNIT
Yes Go to the next step.
No Replace the indicator unit, then go to the next step.
(See INDICATOR UNIT REMOVAL/INSTALLATION ).
4 VERIFY THAT REPAIRS HAVE BEEN COMPLETED
Yes Repeat the inspection from Step 1.

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.
(See DTC TABLE [RETRACTABLE FASTBACK CONTROL MODULE] ).
No DTC troubleshooting completed.