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For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Corvette 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 DTC B3971

DTC Descriptor

DTC B3671: Folding Top Position Sensor

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Circuit/System Description

The folding top control (FTC) module supplies accessory voltage to the top open and closed limit switches. It monitors the signal circuits of these switches to determine the open and closed position of the top.

With the top is in each position, the top open and top closed switches should be as follows:

    • Top closed -- The top closed switch will be closed the scan tool Top Closed Switch parameter will display Active. The top open switch will be open and the scan tool Top Open Switch parameter will display Inactive.
    • Top open -- The top open switch will be closed and the scan tool Top Open Switch parameter should display Active. The top closed switch will open and the scan tool Top Closed Switch parameter will display Inactive.

Conditions for Running the DTC
    • The FTC module is powered.
    • DTC B1327 or B1328 are not set.

Conditions for Setting the DTC

Both the top open and top closed switches are active at the same time.

Action Taken When the DTC Sets
    • The FTC module disables all folding top functions.
    • If the condition occurs during operation of the folding top, once the top control switch is released, the FTC module will send a serial data message to the driver information center (DIC), displaying TOP NOT SECURE.

Conditions for Clearing the DTC
    • A current DTC will clear when a fault is no longer detected.
    • A history DTC will clear after 50 malfunction free ignition cycles.

Reference Information

Schematic Reference

Folding Top Schematics

Connector End View Reference

Power Roof Systems Connector End Views

Description and Operation

Power Folding Top Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Data Definitions

Circuit/System Verification
  1. Ignition ON, top up, verify the scan tool Top Closed Switch parameter displays Active and the Top Open Switch parameter displays Inactive.
  2. Top down, verify the scan tool Top Open Switch parameter displays Active and the Top Closed Switch parameter displays Inactive.

Circuit/System Testing
  1. Ignition OFF, disconnect the harness connector at the top closed switch.
  2. Ignition ON, verify the scan tool Top Closed Switch parameter displays Inactive.
    3. ⇒If not the specified value, test the top closed switch signal circuit for a short to voltage. If the circuit tests normal, replace the FTC module.
  3. Ignition OFF, disconnect the harness connector at the top open switch.
  4. Ignition ON, verify the scan tool Top Open Switch parameter displays Inactive.
    5. ⇒If not the specified value, test the top open switch signal circuit for a short to voltage. If the circuit tests normal, replace the FTC module.
  5. Ignition OFF, reconnect the harness connectors at the top open switch and top closed switch.
  6. Ignition ON, top closed, verify the scan tool Top Closed Switch parameter displays Active.
    7. ⇒If not the specified value, test the top closed switch signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the top closed switch.
  7. Top open, verify the scan tool Top Open Switch parameter displays Active.
    8. ⇒If not the specified value, test the top open switch signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the top open switch.
  8. If all circuits test normal, replace the FTC module.

Component Testing

Top Open Switch - Top Closed Switch

  1. Ignition OFF, disconnect the harness connector at the switch.
  2. Test for infinite resistance between the signal terminal A and the ignition terminal B with the switch in the open position.
    3. ⇒If not the specified value, replace the switch.
  3. Test for less than 2 ohms of resistance between the signal terminal A and the ignition terminal B with the switch in the closed position.
    4. ⇒If greater than the specified range, replace the switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for FTC Module replacement, setup and programming.