GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The folding top control (FTC) module checks the integrity of the signal circuits from the rear compartment lid release close switch at least once every 300 milliseconds. The rear compartment lid release close switch has a constant battery positive voltage supplied. Pressing the rear compartment lid release close switch will apply the battery positive voltage to the rear compartment lid release close switch signal circuit to the FTC module. The FTC module monitors the signal request and will operate the rear compartment lid when battery positive voltage is received.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B3641 Trunk Close Switch Circuit

Conditions for Running the DTC

    • The battery voltage is between 9-16 volts.
    • DTC B1327 is not currently set.

Conditions for Setting the DTC

When the FTC module detects a short to battery in the rear compartment lid release close switch circuit for more than 5 seconds.

Action Taken When the DTC Sets

    • Stores a current and history DTC B3641 in the FTC module.
    • The rear compartment lid pulldown feature will be inactive from the rear compartment lid release close switch.

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

A rear compartment lid release close switch that is held or stuck in the closed position for more than 5 seconds will set this DTC.

Step

Action

Yes

No

Schematic Reference: Body Rear End Schematics

Connector End View Reference: Body Rear End 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, select the display DTCs function in the folding top control (FTC) menu.

Is DTC B3641 set as a current DTC?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections

3

Inspect the rear compartment lid release close switch for a condition in which the switch is stuck in the closed position.

Did you find and correct the condition?

Go to Step 7

Go to Step 4

4

Test the rear compartment lid release close switch signal circuit for a short to B+. Refer to Circuit Testing and Wiring Repairs.

Did you find and correct the condition?

Go to Step 7

Go to Step 5

5

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

Did you find and correct the condition?

Go to Step 7

Go to Step 6

6

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

Did you complete the replacement?

Go to Step 7

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7

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

Does the DTC reset?

Go to Step 2

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