Audi TT Mk2 (8J) Roadster — Convertible Top Troubleshooting Guide¶

Extracted on 2026-07-28 UTC¶

Source: TTForum — FAQ Mk2 Roadster Compendium of Convertible Top Problems & Solutions ¶

Original Author: SwissJetPilot (TTForum)¶

Applicable Vehicles¶

Audi TT Mk2 (8J) Roadster — all years (2006–2014)

Overview¶

The Mk2 TT Roadster convertible top system is generally robust and reliable. The real Achilles' Heel is the Roof Flap Servos (RFS), which cause approximately 90% of reported problems when the roof doesn't open or close properly. The RFS can be serviced as a DIY project.

As the Mk2's continue to age, other mechanical failures may emerge from the hydraulic pump, hydraulic cylinders, latch motor, and various sensors.

Important Diagnostic Requirement¶

To properly diagnose problems with the convertible top, a VAG-compatible OBDII diagnostic device is required. However, only the Ross-Tech VCDS has proven capable of performing the necessary Initialization and Adaptations required to clear faults and reset the convertible top controller.

OBDeleven and similar devices can read fault codes but cannot run the Adaptations or clear roof faults under Address 26 -- Auto Roof.

1. Manual Closing of the Top (Emergency Procedure)¶

If the top fails to operate, you can close and latch it manually to secure the vehicle:

Link: How To: Audi TT (8J) Manually Closing the Convertible Top

A PDF is available in that thread which can be downloaded and printed to have on hand while working.

2. Symptoms Quick-Reference¶

Symptom	Likely Cause
DIS message: "Soft top can not be used"	Fault registered during operation
DIS message: "Soft top not secure"	Manual closure w/out power -- sensors didn't register
Pressing switch -- nothing happens	Failed console switch (E137), or controller lockout
Top unlatches, opens a few inches, then stops	Roof Flap Servo fault
Flaps go up but top doesn't move out of storage	Roof Flap Servo or hydraulic issue
Leading edge reaches windshield but fails to latch	Latch motor or alignment issue
Windows fail to open/close properly	Often associated with Roof Flap Servo faults
Roof hesitates during operation	RFS or Hall Sensor issue
No sound from hydraulic pump behind seats	Pump failure, blown fuse, or thermal shutdown
Rattle sound from front of top	Metallic: latch alignment; Plastic: broken clips
Top opens/closes slowly with no fault codes	Hydraulic valve not fully closed after manual operation
No fault codes but top doesn't work	Failed Hall Sensors (no specific fault codes)

3. Possible Causes -- Detailed¶

3.1 DIS Messages¶

If a fault is registered during top operation, "Soft top can not be used" will display.
After manually closing the top (power off), the controllers won't have seen the sensors activate. Even with the top mechanically secured, "Soft top not secure" may appear. As long as the top is physically secure and the hydraulic pump relief valve is closed, this message can be ignored.

3.2 Low Voltage Condition¶

The Mk2 is notorious for throwing fault codes if the battery voltage drops. The convertible top draws high amperage which can pull down a weak battery quickly -- especially with the engine off and in cold weather.

Recommendation: Only operate the top with the engine running.

3.3 Roof Flap Servo (RFS) Faults¶

The most common problem. Excessive grease on the servo potentiometer contacts causes erratic operation. This is a relatively easy DIY repair.

Related Post: How to: Convertible Roof Flap Servo R&R

Ref: Roadster Roof Flap Servo (RFS) Repair Questions and Answers

3.4 Broken or Damaged RFS¶

If someone has forced a roof flap down, it can break: - The servo arm - The linkage or ball connectors - The gears inside the servo

Ref: Roadster Flap Anchor Snapped

3.5 Failed Console Switch¶

If pressing/pulling the switch does nothing, the switch may be defective. A fault scan should reveal a fault against E137.

3.6 Failed Hall Sensors¶

Located in the left roof frame. These tell the control module if the top is up or stowed. They are known to fail without generating specific fault codes.

VAG Part Number: 8F0 998 350

Refs: - Diagnosing failing Hall sensors via Measurement Blocks - Bench testing a suspect Hall sensor - DIY replacing the F202 Hall Sensor

3.7 Failed Controller (J256)¶

If a repair has been done and the Adaptation/Output Test isn't successful, the controller itself may be faulty.

3.8 Rattle in Front of the Roof¶

Metallic rattle: Check latch alignment, or inspect the latch motor assembly for loose retaining brackets/bolts.
Plastic rattle: One of the three clips inside the plastic cover may be broken or loose.

Ref: Convertible Top Latch Motor Assembly Details

3.9 Failed Hydraulic Pump¶

The pump has an automatic thermal shut-off to prevent burning out the motor. If it stops after several attempts, allow it to cool.
Check the 30A fuse, No. 4 on fuse panel "F" (behind the right trunk panel).
If the fuse is good and the pump still doesn't run, refer to the TSB.

Refs: - SSP 391 -- Self Study Program - Convertible Top Hydraulic Pump Drive Motor TSB - Hydraulic Pump discussion - Roadster Roof Hydraulic Pump thread

3.10 Leaking Hydraulic Pump or Cylinders¶

Check for low fluid by inspecting hydraulic line connections for signs of leaking.
Also check the plastic half of the pump (which holds the fluid).
Cylinders are located on both sides of the roof assembly. With the top open and roof flap released in the "up" position, inspect where lines connect and at the piston rod seal.

Note: Due to the roof design, cylinders can only be accessed/serviced by removing the entire roof assembly.

Ref: Convertible Top Piston Replacement

3.11 Top Opens/Closes Slowly¶

If you performed a manual open/close, ensure the hydraulic valve is completely screwed closed. If not fully closed, the top won't operate properly.

Ref: TTS Roadster Roof Slow Fix

3.12 Roof Control Module Revision-B Relay Problems¶

Some roof modules (specifically Revision B, part number 8J7 959 255 B) have been reported to have bad relays. If the VCDS Output/Initialization test fails, check the module revision.

Ref: 2009 2.0 TDI Roadster Roof Control Module Revision-B Relay Problems

4. Diagnostic Tools¶

Tool	Capability
Ross-Tech VCDS	Full read/write, fault codes, Output Test/Initialization, Measurement Blocks, Adaptations
OBDeleven	Read fault codes only -- cannot run Output Test/Initialization or clear Address 26 faults
Generic OBDII	Limited or no VAG-specific convertible top functionality

Refs: - FAQ -- OBDII Diagnostic Device Reviews - FAQ -- VCDS Open Box Review - FAQ -- OBDeleven Open Box Review

Terminology Note¶

There is some inconsistency between the terms Adaptation, Basic Setting, and Output Test in the Audi workshop manual. In 26-Auto Roof Open Controller, both [Basic Setting-04] and [Adaptation-10] are greyed out -- the only option is [Output Test-03]. This output test performs the required Roof Flap Servo initialization.

Ref: FAQ -- Mk2 Roadster Convertible Measurement Blocks, Fault Codes & Output Test/Initialization

5. First-Aid Reset Procedure¶

If the top fails and you don't have a diagnostic tool handy, try this:

Insert the key and turn ignition to ACC (don't start the car)
Perform a manual open and close of the top, ensuring it fully latches once closed
Turn off the ignition and remove the key
Start the car and attempt to open the roof normally

If the control module "sees" all the switches activate properly, it may clear the fault. If this doesn't work, a full OBDII fault scan is required.

6. Repair Options¶

6.1 Roof Flap Servo R&R¶

The most common repair. Servos can be removed, cleaned of excess grease on the potentiometer contacts, and reinstalled.

Link: How to: Convertible Roof Flap Servo R&R

6.2 Soft Top "Cannot Be Used" Message¶

Dedicated FAQ on what to do when this DIS message appears.

Link: FAQ -- Mk2 Roadster "Soft Top Cannot Be Used" Message

6.3 Convertible Roof Alignment¶

If the top doesn't close flush or seal properly.

Link: How to: Convertible Roof Alignment

6.4 Roof Flap Alignment¶

If the flaps themselves don't sit flush.

Link: How to: Convertible Roof Flap Alignment

6.5 Convertible Top Care (OEM Factory Instructions)¶

Official care and cleaning recommendations for the soft top fabric.

Link: FAQ -- Convertible Top Care OEM Factory Instructions

6.6 Soft Top Window Debond Repair¶

How to repair a detached rear window glass from the fabric.

Link: How to: Soft Top Window Debond Repair

6.7 Roadster Drain Hose Access¶

How to access and clear the drain hoses.

Link: How to: Roadster Drain Hose Access

6.8 Hydraulics -- Pump & Cylinders¶

Pump: - Pump discussion

Cylinders: - Piston replacement

New cylinders can be purchased from Audi or rebuilt by a specialist. The entire top must be removed to replace them.

6.9 Latch Motor Assembly¶

Details on the latching motor, including replacing the spline shaft.

Link: FAQ -- Mk2 TT (8J) Convertible Top Latch Motor Assembly Details

7. Interior Panel Removal¶

Panel	Link
A-Pillar Cover	How To: Mk2 Roadster A-Pillar Cover Removal
Seat Rear Panel	Roadster Seat Rear Panel Removal
Trunk Lid Panel	Roadster Trunk Lid Panel Removal
Console Tray / Phone Kit	Roadster Console Tray Phone Kit Removal
Trunk Buffer Discs	Roadster Trunk Buffer Discs
Trunk Escape Handle (NA)	North American Trunk Escape Handle Removal

8. Part Numbers¶

Item	Part Number	Description
Crank Arm Tool	`8J7825381A`	Emergency manual crank tool
Spline Shaft Kit	`8J7-898-410-C`	Spline shaft, latch motor retaining screw, clip
RFS Repair Kit	`8J7-898-943`	RFS arms (L&R), ball link arms (x2), ball pins, nuts (x2), M4x15 (x6) screws
Retaining Clips	`D0867299A` / `8E0867276`	Cover panel clips (x3)
Hall Sensor	`8F0 998 350`	F171 / F202 replacement
Controller (Rev B)	`8J7 959 255 B`	Known relay issues

Note: Parts are often cheaper directly from Audi. Use LLLParts for diagrams.

9. Soft Top Fabric & Rear Glass¶

9.1 Fabric Material¶

The OEM soft top fabric is Sonnenland by Haartz -- German-made 3-ply topping: - Acrylic twill-weave facing - Rubber inner-layer - Polyester dobby backing

9.2 Patch vs. Replace¶

Patches are a temporary solution. Factors affecting durability: - Material variance (old vs. new patch material) - Location (flat area vs. folded section) - Size of the hole - Bonding agent durability/flexibility - Mechanical stresses from operation - Environmental factors (heat vs. cold)

Recommended adhesive: Teroson PU 6700 (Henkle) -- recommended by Jaguar for rear glass de-bonding repairs.

Fabric samples: BAS International (car-hood.co.uk)

9.3 Expected Costs¶

Item	Cost
New cover (from LLLParts)	~2,500 EUR
Labor (13-16 hrs at 90 EUR/hr)	~1,170-1,440 EUR
Total installed	~3,700-4,000 EUR

Rear glass is not separately replaceable -- new cover includes new glass.

9.4 Separated Rear Glass¶

Can be repaired as a DIY with the right tools and materials. Success depends on separation extent and skill.

Ref: Roadster Rear Window Glass Bond Failing

10. Rear Window Defroster¶

Condition	Defroster Behavior
Top is open	Disabled
Top being opened/closed	Disabled during operation
Engine not running	Disabled

Three control units involved: 1. Convertible top control unit (J256) 2. Power supply control unit (J519) 3. Climatronic control unit (J255)

WSM Ref: General Body Repairs, Exterior (Convertible Top) -- RG 50, 55, 57, 61, 63, 64, 66 -- A005TT00220

11. SSP 391 (Self-Study Program)¶

The official Audi Self-Study Program for the Mk2 Roadster convertible top -- covers operation, component locations, and system electrical overview.

Download: SSP 391 Audi TT Roadster Mk2 (PDF) -- local copy, or download from TTForum

12. Resources¶

Key References¶

Specialist¶

VagPro (UK): vagpro.co.uk -- reported successful Hall sensor and convertible top repairs.

13. Other Common Problems¶

13.1 Damp Behind Passenger Seat¶

Often caused by damaged drip trays from items placed in the rear top stowage area cracking the trays when the top lowers.

Ref: Damp Behind Passenger Seat

13.2 Corrosion / Rust¶

Check where the roof meets the metal bodywork. Signs: paint bubbles and white rust.

Ref: TT Roadster Mk2 Rust

Source thread by SwissJetPilot on TTForum, Mar 2020 -- updated Sep 2025.