Based on what we know and the photos from
Big rex 2 it would seem to me the steps for replacing the F202 Hall Switch would go something like this -
Parts:
• Audi Repair Hall Sensor (Audi A5) PN: 8F0 998 350
• 2-Wire Micro Clamp Connector (x1)
Tools:
• Torx T20 bit
• Small wire cutters
• Flexible Magnetic pick-up tool (in case you drop one of the screws)
• Dual 20/22 AWG Cable (0.2-0.5mm²) clamping cable connector (see image below)
• Loctite® Threadlocker Blue 242®
• Nylon pry-bars to assist with interior panel removal
Procedure:
1.) Open and stow the convertible top.
2.) Note - to provide better access to the working area of the Frame, it may be advisable to remove the interior panels behind the seat and below the roll bar.
3.) Release the ball-arm connector from the Roof Flap and snap into place under the Roof Flap. The Roof Flap will default to the vertical (up) position. If needed for additional working space, the entire Roof Flap assembly can be removed.
4.) Carefully insert a towel into the area under the Frame and Hall Sensor. This is to catch the screws or your tools should you accidentally drop them.
5.) Use a T20 Torx bit and unscrew the Hall Sensor retaining screw until the Hall Sensor can be removed from the slot in the Frame.
6.) Use a T20 Torx bit and unscrew the Harness Cable Clamp retaining screw to release the cable clamp from the Frame. This will provide you with some additional slack in the cable and make the next steps a bit easier. Note - Do not remove the cable clamp from the harness.
7.) Using a pair of small wire cutters, cut both wires as close as possible to the old Hall Sensor. The old Hall Sensor can be discarded.
8.) Carefully trim back about 1" of the harness so you can access both Hall Sensor wires for the next steps.
9.) Using the 2-Wire Micro Clamp Connector, secure both wires from the harness to one side of the connector. Note - the wire insulation on the brown and black wires does not need to be stripped back. Follow the manufacturers' instructions (shown below) and be sure the wires are fully inserted before clamping the connector.
10.) Secure both wires from the new Hall Sensor into the 2-Wire Micro Clamp Connector. Be sure you have black to black and brown to brown. Note - the wires on the replacement Hall Sensor are longer than needed. Either cut them to the appropriate length before adding the connector, or simply loop the wires and secure them with a small cable tie.
11.) Reposition the Cable Connector and secure the T20 screw.
12.) Position the Hall Sensor into the slot in the Frame and secure the T20 screw. Note - apply a very small dab of Loctite® Threadlocker Blue 242 to the threads.
At this point, it should be possible to close the top automatically. If the top fails to operate check for faults and use VCDS to run the convertible top initialization (link
here).
13.) Lower the Roof Flap and reconnect the ball-arm connector to the Roof Flap Servo and reinstall the interior panels.
Given the limited space where the Hall Sensor is located, these dual-wire clamping connectors would be an alternative solution to splicing or soldering the connections together. Be sure to get the connector designed for 20/22 AWG Cable (0.2-0.5mm²). These are available from Amazon and other resellers.
Locations of the Hall Sensor (1) and Harness Clamp (2) T20 Torx screws shown from the back of the Frame.
You might also ask this guy, as he recently did his...
