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Home >> Mazda >> 2021 >> MX-5 Miata Club, Standard Trans >> Repair and Diagnosis >> Body & Frame >> Door Locks >> On-Board Diagnostic - Retractable Fastback Control Module >> DTC B1DA6-29: Incorrect Top Lock Position [Retractable Hardtop Control Module] >> Diagnostic Procedure
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Diagnostic Procedure

DTC B1DA6:29 (RETRACTABLE HARDTOP CONTROL MODULE) DIAGNOSTIC PROCEDURE

Step Inspection Action
1 VERIFY OTHER RETRACTABLE HARDTOP CONTROL MODULE DTCs
Yes Replace the retractable hardtop control module, then go to Step 8.
(See RETRACTABLE HARDTOP CONTROL MODULE REMOVAL/INSTALLATION .)
No Go to the next step.
2 INSPECT TOP LOCK SWITCH CIRCUIT FOR SHORT TO GROUND
  • Switch the ignition off.
  • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)
  • Disconnect the retractable hardtop control module and top lock switch connectors.
  • Inspect for continuity between the following terminal (wiring harness-side) and body ground:
    • Top lock switch terminal A
  • Is there continuity?
Yes Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
  • Retractable hardtop control module terminal 1G and top lock switch terminal A

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 8.

No Go to the next step.
3 INSPECT TOP LOCK SWITCH
Yes Go to the next step.
No Replace the top lock switch, then go to Step 8.
(See TOP LOCK STRIKER REMOVAL/INSTALLATION .)
4 INSPECT FRONT ROOF LINK LIMIT SWITCH (LH) CIRCUIT FOR SHORT TO GROUND
  • Disconnect the front roof link limit switch (LH) connector.
  • Verify that the retractable hardtop control module and front roof link limit switch (LH) connectors are disconnected.
  • Inspect for continuity between the following terminals (wiring harness-side) and body ground:
    • Front roof link limit switch (LH) terminal C
    • Front roof link limit switch (LH) terminal D
    • Front roof link limit switch (LH) terminal B
  • Is there continuity?
Yes Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
  • Retractable hardtop control module terminal 4L and front roof link limit switch (LH) terminal C
  • Retractable hardtop control module terminal 4M and front roof link limit switch (LH) terminal D
  • Retractable hardtop control module terminal 4K and front roof link limit switch (LH) terminal B

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 8.

No Go to the next step.
5 INSPECT FRONT ROOF LINK LIMIT SWITCH (LH)
Yes Go to the next step.
No Replace the front roof link limit switch (LH), then go to Step 8.
(See ROOF LINK LIMIT SWITCH REMOVAL/INSTALLATION .)
6 INSPECT REAR ROOF LINK LIMIT SWITCH (LH) CIRCUIT FOR SHORT TO GROUND
  • Disconnect the rear roof link limit switch (LH) connector.
  • Verify that the retractable hardtop control module and rear roof link limit switch (LH) connectors are disconnected.
  • Inspect for continuity between the following terminals (wiring harness-side) and body ground:
    • Rear roof link limit switch (LH) terminal A
    • Rear roof link limit switch (LH) terminal C
  • Is there continuity?
Yes Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
  • Retractable hardtop control module terminal 4I and rear roof link limit switch (LH) terminal A
  • Retractable hardtop control module terminal 4F and rear roof link limit switch (LH) terminal C

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 8.

No Go to the next step.
7 INSPECT REAR ROOF LINK LIMIT SWITCH (LH)
Yes Go to the next step.
No Replace the rear roof link limit switch (LH), then go to the next step.
(See RETRACTABLE HARDTOP CONTROL MODULE REMOVAL/INSTALLATION .)
8 VERIFY THAT REPAIRS HAVE BEEN COMPLETED
Yes Repeat the inspection from Step 1.
No Go to the next step.
9 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 HARDTOP CONTROL MODULE] .)
No DTC troubleshooting completed.