GM Service Manual Online
For 1990-2009 cars only

Circuit 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.

When the top is in the closed position the following definitions of the limit switches should be true:

    • Top closed switch-The switch will be closed to voltage and the scan tool parameter should display Active.
    • Top open switch-The switch will be open and the scan tool parameter should display Inactive.

DTC Descriptor

The diagnostic procedure supports the following DTC:

DTC B3671 Folding Top Position Sensor

Conditions for Running the DTC

The FTC module must be powered and can not have B1327 or B1328 set as active DTCs for this DTC to set.

Conditions for Setting the DTC

The FTC module will set B3971 as a current DTC if it senses that both the top open and top closed limit 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 class 2 message to the driver information center (DIC), displaying TOP NOT SECURE.

Conditions for Clearing the DTC

    • This DTC will clear on the current status after the condition for setting the fault is corrected.
    • A history DTC will clear after 50 consecutive ignition cycles without a fault present.
    • History and current DTC can be cleared using the scan tool.

Diagnostic Aids

If the DTC does not reset after the code is cleared, then the switch may be the intermittent fault. Refer to Testing for Intermittent Conditions and Poor Connections .

Step

Action

Yes

No

Schematic Reference: Folding Top Schematics

Connector End View Reference: Folding Top Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the Top Open and Top Closed Limit Switch parameters in the Folding Top Module Inputs data list.

Does the scan tool indicate that both, the Top Open and Top Closed Limit Switches are Active at the same time?

Go to Step 3

Go to Diagnostic Aids

3

Is the folding top in the closed position?

Go to Step 4

Go to Step 5

4

  1. Turn OFF the ignition.
  2. Disconnect the top open switch.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the Top Open Limit Switch parameter.

Does the Top Open Limit Switch parameter display Active?

Go to Step 6

Go to Step 8

5

  1. Turn OFF the ignition.
  2. Disconnect the top closed switch.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the Top Closed Limit Switch parameter.

Does the Top Closed Limit Switch parameter display Active?

Go to Step 7

Go to Step 9

6

Test the signal circuit of the top open switch for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 10

7

Test the signal circuit of the top closed switch for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 10

8

Inspect for poor connections at the harness connector of the top closed limit switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 11

9

Inspect for poor connections at the harness connector of the top open limit switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 12

10

Inspect for poor connections at the harness connector of the folding top control (FTC) module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 14

Go to Step 13

11

Replace the top closed limit switch. Refer to Folding Top Position Switch Replacement .

Did you complete the replacement?

Go to Step 14

--

12

Replace the folding top open limit switch. Refer to Folding Top Position Switch Replacement .

Did you complete the replacement?

Go to Step 14

--

13

Replace the FTC module. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 14

--

14

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK