GM Service Manual Online
For 1990-2009 cars only

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 B3665: Front Tonneau Position Error

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Folding Top Control Module Battery Voltage

1

1

--

--

Folding Top Control Module Control

B1420

B1420

--

--

Folding Top Control Module Ground

--

1, 2

--

--

Folding Top Control Switch Battery Voltage

2

2

--

--

Folding Top Control Switch Close Signal

2

2

B3602

--

Folding Top Control Switch Open Signal

2

2

B3602

--

Front Panel Position Sensor 5-Volt Reference

B3665, B3666, B3971

B3665

B3665, B3666, B3670, B3971

--

Front Panel Position Sensor Signal

B3665

B3665

B3665

--

Front Panel Position Sensor Low Reference

--

B3665

--

--

Folding Top Position Sensor 5-Volt Reference

B3665, B3666, B3971

B3971

B3665, B3666, B3670, B3971

--

Folding Top Position Sensor Signal

B3971

B3971

B3971

--

Folding Top Position Sensor Low Reference

--

B3971

--

--

Rear Panel Position Sensor 5-Volt Reference

B3665, B3666, B3971

B3666

B3665, B3666, B3670, B3971

--

Rear Panel Position Sensor Signal

B3666

B3666

B3666

--

Rear Panel Position Sensor Low Reference

--

B3666

--

--

Folding Top Pump Motor Temperature Sensor 5-Volt Reference

B3665, B3666, B3971

2, 7

B3665, B3666, B3971, B3670

--

Folding Top Pump Motor Temperature Sensor Signal

2, 7

2, 7

B3670

--

Hard Top Connected Signal

B1420

4, 7

B1310

--

Folding Top Closed Switch Control

B1420

4, 7

--

--

Front Latched Position Switch Signal

B1420, 3, 4, 7

3, 4, 7

B1300

--

Front Latched Position Switch Control

B1420

3, 4, 7

--

--

Front Unlatched Position Switch Signal

B1420, 9

9

B1300

--

Front Unlatched Position Switch Control

B1420

9

--

--

Compartment Partition Position Switch Signal

B1420, 2, 7

2, 7

8

--

Compartment Partition Position Switch Control

B1420

2, 7

--

--

Pump Direction A Control

B1011

2

--

--

Pump Direction B Control

B1011

2

--

--

Rear Compartment Lid Open Switch Signal

B1420, 3, 4

3, 4

B3669

--

Rear Compartment Lid Open Switch Control

B1420

3, 4

--

--

Folding Top Valve 1 Control

1

3

--

--

Folding Top Valve 1 - Ground

--

3

--

--

Folding Top Valve 2 Control

1

4

--

--

Folding Top Valve 2 - Ground

--

4

--

--

Folding Top Valve 3 Control

1

3, 4, 6

--

--

Folding Top Valve 3 - Ground

--

3, 4, 6

--

--

Folding Top Valve 4 Control

1

B1297, 3, 4, 5

--

--

Folding Top Valve 4 - Ground

--

B1297, 3, 4, 5

--

--

Folding Top Valve 5 Control

1

2

--

--

Folding Top Valve 5 - Ground

--

2

--

--

1. No communication with the FTC module

2. Power folding top is inoperative

3. Power folding top does not open or complete the top opening procedure

4. Power folding top does not close or complete the top closing procedure

5. Rear Compartment lid will not open

6. Rear compartment lid will not close

7. DIC warning message displayed

8. Folding top will operate with the rear compartment partition removed

9. No effect on power folding top operation

Circuit/System Description

The folding top control (FTC) module supplies a 5-volt reference and low reference circuit to the front panel position sensor. The position sensor sends a voltage signal, that varies with the movement of the front panel, through the signal circuit to the FTC module. Then based on this voltage signal, the FTC module determines the position of the front panel and continues with the operating sequence. This voltage is converted and displayed as counts on the scan tool. Each count equals 0.0196 volt.

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

If the FTC module sees the analog input from the front panel position sensor as either less than 12 counts or greater than 242 counts. The position sensor will be considered out of range and the FTC module will set this DTC.

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

    • The FTC module will clear the DTC as an active malfunction when it sees the analog input from this position sensor as between 12 counts and 242 counts during one cycle of checking the FTC module inputs.
    • A history DTC will clear after 50 consecutive ignition cycles without a fault present.

Diagnostic Aids

    • All position sensors use common ground and 5-volt reference circuits.
    • Multiple DTCs, B3665, B3666 B3670, and B3971 can set:
       - If the 5-volt reference circuit is shorted to voltage
       - If the 5-volt reference circuit is shorted to ground
       - If the position sensor ground circuit is open
    • The Rear Compartment Lid is also referenced as the Deck Lid for this vehicle.

Reference Information

Schematic Reference

Folding Top Schematics

Connector End View Reference

Component 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

Control Module References for Scan Tool Information

Circuit/System Verification

Ignition ON, observe the scan tool Front Tonneau Position Sensor parameter. The reading should be between 12 and 242 Counts.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the folding top stowage compartment front panel position sensor.
  2. Ignition OFF, test for less than 1 ohm between the low reference circuit terminal C and ground.
  3. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuits test normal, replace the FTC module.
  4. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal A and ground.
  5. If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the FTC module.
    If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the FTC module.
  6. Verify the scan tool Front Tonneau Position Sensor parameter is less than 10 Counts.
  7. If greater than the specified range, test the signal circuit terminal B for a short to voltage. If the circuit tests normal, replace the FTC module.
  8. Install a 3A fused jumper wire between the signal circuit terminal B and the 5-volt reference circuit terminal A. Verify the scan tool Front Tonneau Position Sensor parameter is greater than 242 Counts.
  9. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the FTC module.
  10. If all circuits test normal, test or replace the folding top stowage compartment front panel position sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Folding Top Stowage Compartment Front Closeout Panel Position Switch Replacement
    •  Control Module References for FTC module replacement, setup, and programming