GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2007 🢒 G6 🢒 DTC 🢒 DTC B3674

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B3674 01: Movable Roof Control Valve 1 Circuit short to battery

DTC B3674 02: Movable Roof Control Valve 1 Circuit short to ground

DTC B3674 04: Movable Roof Control Valve 1 Circuit open circuit

Circuit/System Description

The folding top uses electronically controlled valves to control the flow of hydraulic fluid. The folding top control (FTC) module controls Valve 1 (V1) by supplying voltage to the valve. The FTC Module also monitors the control circuit of V1 for proper operation.

Conditions for Running the DTC

The FTC module is active.

Conditions for Setting the DTC

B3674 01

A short to voltage on the control circuit of V1.

B3674 02

A short to ground on the control circuit of V1.

B3674 04

An open on the control circuit or low reference circuit of V1.

Action Taken When the DTC Sets

The top is disabled.

Conditions for Clearing the DTC

The fault is no longer present and the top completes one cycle.

Reference Information

Schematic Reference

Folding Top Schematics

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
    •  Scan Tool Output Controls

Circuit/System Testing

B3674 01

Test the control circuit of V1 for a short to voltage. If circuit OK, replace FTC Module.

B3674 02

Test the control circuit of V1 for a short to ground. If circuit OK, replace FTC Module.

B3674 04

  1. Disconnect V1.
  2. Probe the control circuit of V1 with a test lamp connected to ground.
  3. Command V1 on with a scan tool. The test lamp should illuminate.
    4. ⇒If the test lamp does not illuminate, test the control circuit for an open or high resistance.
    ⇒If circuit OK, replace FTC Module.
  4. Probe the low reference circuit with a test lamp connected to B+. The test lamp should illuminate.
    5. ⇒If the test lamp does not illuminate, test the low reference circuit for an open or high resistance.
    ⇒If circuit OK, replace FTC Module.
  5. If circuits tests OK, replace V1.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Folding Top Pump with Motor Replacement
    •  Folding Top Control Module Replacement