GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Corvette 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 Power Folding Top Does Not Close

Diagnostic Aids
    • Complete the check list, prior to performing the diagnosis:
       - When the folding top control switch is pressed, check for driver information center (DIC) warning messages.
       - Windows are normalized. Refer to Power Windows Description and Operation .
       - Luggage barrier is installed and secured, closing the luggage barrier switch.
       - Vehicle is in PARK or the park brake is applied with manual transmission.
       - Press the ignition to ACCY or RUN, with the engine OFF.
       - Hydraulic fluid bypass valve in the operating position, turned clockwise, located above the pump motor.
       - Operating temperature is normal.
    • When using the scan tool, the folding top cover is referenced as the tonneau.
    • If a repair is made to a signal circuit for a fault to ground, test the component of that circuit for proper operation.
    • Using the scan tool to access the History parameters for the folding top control (FTC) module, will display the last status of the items listed.

Test Description

The number below refers to the step number on the diagnostic table.

  1. This step determines the integrity of valve 3. When commanding the valve on, be careful not to confuse the low audible click from the valve with the louder click from the relay in the FTC module.

Step

Action

Yes

No

Schematic Reference: Folding Top Schematics

Connector End View Reference: Power Roof Systems Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Verify that the Power Folding Top Does Not Close complaint is present.

Does the power folding top close as described in the system description and operation?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Press the folding top close control switch.

Did the folding top cover latch actuator release?

Go to Step 4

Go to Folding Top Stowage Compartment Lid Release Inoperative

4

Did the folding top cover raise to the open position?

Go to Step 5

Go to Power Folding Top Inoperative

5

While the folding top cover was raising to the open position, did the folding top cover pull down striker extend to the up position?

Go to Step 6

Go to Folding Top Stowage Compartment Lid Release Inoperative

6

During the folding top close operation, did top movement stop after the folding top cover opened?

Go to Step 13

Go to Step 7

7

During the folding top close operation, did top movement stop after the folding top raised to the up position?

Go to Step 16

Go to Step 8

8

During the folding top close operation, did top movement stop after the 5 bow raised?

Go to Step 19

Go to Step 9

9

During the power folding top close operation, did top movement stop after the folding top cover closed?

Go to Step 10

Go to Step 11

10

Important: Ensure that the folding top cover is latched before continuing with this diagnostic procedure.

After the folding top cover closed and latched, did the folding top cover pull down retract to the down position?

Go to Step 39

Go to Folding Top Stowage Compartment Lid Release Inoperative

11

During the power folding top close operation, did the 1 bow lower down onto the windshield?

Go to Step 12

Go to Step 24

12

Could an audible chime be heard after the completion of the top closed function?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 27

13

With a scan tool, observe the Tonneau Open Limit Switch parameter in the Folding Top Module Inputs data list.

Does the Tonneau Open Limit Switch parameter display Active?

Go to Step 22

Go to Step 14

14
  1. Disconnect the folding top cover open switch connector.
  2. Connect a test lamp from the accessory voltage circuit of the folding top cover open switch connector to a good ground.

Does the test lamp illuminate?

Go to Step 15

Go to Step 42

15
  1. Connect a 3-amp fused jumper wire between the accessory voltage circuit and the signal circuit of the folding top cover open switch connector.
  2. With a scan tool, observe the Tonneau Open Limit Switch parameter.

Does the Tonneau Open Limit Switch parameter display Active?

Go to Step 38

Go to Step 34

16

With a scan tool, observe the Top Closed Limit Switch parameter in the Folding Top Module Inputs data list.

Does the Top Closed Limit Switch parameter display Active?

Go to Step 39

Go to Step 17

17
  1. Disconnect the top closed switch connector.
  2. Connect a test lamp from the accessory voltage circuit of the top closed switch connector to a good ground.

Does the test lamp illuminate?

Go to Step 18

Go to Step 42

18
  1. Connect a 3-amp fused jumper wire between the accessory voltage circuit and the signal circuit of the top closed switch connector.
  2. With a scan tool, observe the Top Closed Limit Switch parameter.

Does the Top Closed Limit Switch parameter display Active?

Go to Step 37

Go to Step 35

19

With a scan tool, observe the 5 Bow Raised Pos. Switch parameter in the Folding Top Module Inputs data list.

Does the 5 Bow Raised Pos. Switch parameter display Active?

Go to Step 22

Go to Step 20

20
  1. Disconnect the 5 bow raised switch connector.
  2. Connect a test lamp from the accessory voltage circuit of the 5 bow raised switch connector to a good ground.

Does the test lamp illuminate?

Go to Step 21

Go to Step 42

21
  1. Connect a 3-amp fused jumper wire between the accessory voltage circuit and the signal circuit of the 5 bow raised switch connector.
  2. With a scan tool, observe the 5 Bow Raised Pos. Switch parameter.

Does the 5 Bow Raised Pos. Switch parameter display Active?

Go to Step 37

Go to Step 30

22

With a scan tool, observe the Power Pull Down Ajar Status parameter in the Folding Top Module Inputs data list.

Does the Power Pull Down Ajar Status parameter display Ajar?

Go to Step 39

Go to Step 23

23
  1. Disconnect the folding top cover pull down actuator connector.
  2. Connect a 3-amp jumper wire from the folding top cover pull down ajar signal circuit of the connector to a good ground.
  3. With a scan tool, observe the Power Pull Down Ajar Status parameter.

Does the Power Pull Down Ajar Status parameter display Ajar?

Go to Folding Top Stowage Compartment Lid Release Inoperative

Go to Step 33

24

  1. Wait four minutes for the module to release the pressure in the hydraulic system.
  2. Manually open the folding top cover to access the hydraulic fluid bypass valve.
  3. Turn the hydraulic fluid bypass valve counterclockwise to inhibit folding top movement.
  4. Navigate the scan tool to Valve 3 in the Roof, Special Functions, FTC data list.
  5. With the scan tool command Valve 3 ON.

Can an audible click be heard from the valve when it is commanded ON?

Go to Step 48

Go to Step 25

25
  1. Disconnect the valve 3 harness connector.
  2. Connect a test lamp from the control circuit of the valve 3 connector to a good ground.
  3. With a scan tool command Valve 3 ON.

Does the test lamp illuminate when the valve is commanded ON?

Go to Step 26

Go to Step 32

26
  1. Connect a test lamp between the control circuit of the valve 3 connector and the ground circuit of the valve 3 connector.
  2. With a scan tool command Valve 3 ON.

Does the test lamp illuminate when the valve is commanded ON?

Go to Step 41

Go to Step 43

27

With a scan tool, observe the 5 Bow Lowered Pos. Switch parameter in the Folding Top Module Inputs data list.

Does the 5 Bow Lowered Pos. Switch parameter display Active?

Go to Step 39

Go to Step 28

28
  1. Disconnect the 5 bow lowered switch connector.
  2. Connect a test lamp from the accessory voltage circuit of the 5 bow lowered switch connector to a good ground.

Does the test lamp illuminate?

Go to Step 29

Go to Step 42

29
  1. Connect a 3-amp fused jumper wire between the accessory voltage circuit and the signal circuit of the 5 bow lowered switch connector.
  2. With a scan tool, observe the 5 Bow Lowered Pos. Switch parameter.

Does the 5 Bow Lowered Pos. Switch parameter display Active?

Go to Step 37

Go to Step 31

30

Test the signal circuit of the 5 bow raised switch for an open. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 49

Go to Step 39

31

Test the signal circuit of the 5 bow lowered switch for an open. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 49

Go to Step 39

32

Test the control circuit of the inoperative valve for a short to ground or an open. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 49

Go to Step 39

33

Test the folding top cover pull down ajar signal circuit for an open. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 49

Go to Step 40

34

Test the signal circuit of the folding top cover open switch for an open. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 49

Go to Step 39

35

Test the signal circuit of the top closed switch for an open. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 49

Go to Step 39

36

Test the folding top cover pull down ajar signal circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 49

Go to Step 40

37

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

Did you find and correct the condition?

Go to Step 49

Go to Step 44

38

Inspect for poor connections at the harness connector of the folding top cover 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 49

Go to Step 45

39

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 to Connector Repairs .

Did you find and correct the condition?

Go to Step 49

Go to Step 46

40

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

Did you find and correct the condition?

Go to Step 49

Go to Step 47

41

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

Did you find and correct the condition?

Go to Step 49

Go to Step 48

42

Repair the open in the accessory voltage circuit of the inoperative limit or position switch. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 49

--

43

Repair the high resistance or open in the ground circuit of the inoperative valve. Refer to Wiring Repairs .

Did you complete the repair?

Go to Step 49

--

44

Replace the inoperative limit or position switch. Refer to Power Folding Top Limit Switches Replacements .

Did you complete the replacement?

Go to Step 49

--

45

Important: The folding top cover open limit switch is an internal part of the folding top cover hydraulic cylinder assembly that is not serviced separately.

Replace the folding top cover open limit switch. Refer to Folding Top Cylinder Replacement .

Did you complete the replacement?

Go to Step 49

--

46

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

Did you complete the replacement?

Go to Step 49

--

47

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

Did you complete the replacement?

Go to Step 49

--

48

Replace the folding top pump, valve, and motor assembly. Refer to Folding Top Pump with Motor Replacement .

Did you complete the replacement?

Go to Step 49

--

49
  1. Turn OFF the ignition.
  2. Disconnect any jumper wires.
  3. Connect all previously disconnected components.
  4. Replace any open fuses, if necessary.
  5. Turn the bypass valve, clockwise, to allow rear folding top cover movement.
  6. Press the ignition to ACCY or RUN, with the engine OFF.
  7. Use the scan tool to clear any DTCs.
  8. Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2