Wiki article summarizing VW TDI emissions cheating so far, click here. Anyone logged in can edit it by clicking the "edit" button on the upper right of the page. It's a reference so please post any comments or questions in the forum. It's a work in progress so feel free to update it!
Turn signal and blinker light replacement, side view mirror removal
How to replace the turn signal, replace the mirror, or remove the housing in mk4 Passat or mk5 VW Jetta, Golf, Rabbit, and GTIdifficulty: 1/5
This article shows how to remove or replace a broken mirror, turn signal, side mirror plastic housing, or motor on mk5 VW Jetta, Golf, Rabbit, or GTI. Also applies to late mk4 Passat (uses same assembly)
The reason why the JSW/GSW Sportwagen TDI is also included is because despite being called a mk6 after 2010, they still use the mk5 side view mirrors. This is because they're still built off a mk5 chassis. The side view mirror housing, glass, motor, and turn signal are also used in the mk4 VW Passat after about 2003-2004. The wiring harness may be different but the rest should be interchangeable.
A common reason to remove the side view mirror is to replace it with a blind spot aspheric mirror. This is a wide angle mirror. They are not DOT approved on the driver's side and may not be legal where you live so installation is your responsibility. See 1000q: blind spot mirror installation on mk5 VW for more details.
The side view mirror turn signals are LED and should never require a new bulb. They are sealed non serviceable units. Here it is disassembled. In my case, I think someone hit the mirror housing in a parking lot which broke the seal and let moisture enter. This corroded the circuit board. I got it working after a quick repair but I threw out the assembly because the cover was cracked and replacements are cheap. There is a single LED in the front and two on the sides.
T10 torx screwdriver
phillips screwdriver if mk4 VW Passat
Left turn signal VW# 1k0 949 101 (1k0949101)
left mirror housing: VW# 1k0 857 537 gru (1k0857537gru) primed
Right turn signal VW# 1k0 949 102 (1k0949102)
right mirror housing VW# 1k0 857 538 gru (1k0857538gru) primed
For regular, blind spot, or tinted mirror part numbers, see the blind spot mirror install linked above.
Procedure to remove the side view mirror on VW Golf, Jetta, or Passat
Turn the mirror all the way to the inside edge. Stick your fingers at the edges of the mirror and gently peel it back. The mirror is plastic so it has some flex.
Remove the heater wires and the mirror. Note which wire goes where. If you have a mk4 Passat, the center position of the mirror adjustment knob isn't off, it's actually heat (pictured below). As a result, it's very common for it to be burnt out. Later cars like the mk5 Jetta TDI or Golf TDI changed the center position to off.
Side view motor removal and replacement
To remove the motor, remove the 3x T10 torx screws. If you have a Passat, they are phillips screws. Unplug the motor plug and remove the motor. I can't remember, but I think removing the motor is necessary to remove the black inner trim (that later cars don't have). First try working around it.
Mirror housing/cover and turn signal removal
To remove the mirror cover, use a screwdriver wrapped in tape or a plastic pry tool to pull the housing cover straight up. After you release the clips holding the cover to the turn signal (shown below for illustration), the cover should pop straight up. I found that if you fold the entire side view mirror assembly in or out, you can use a pry to help pop the inside of the housing straight up.
Here is what you're removing.
Here are the clips on the turn signal shown after removal (blue arrows). You want to release these before pulling the housing up.
If you have a Passat, the turn signal wire goes through a little holder marked with the green box. The later cars don't have this.
Now push the clips marked with purple arrows and slide the black inner trim off towards the rear of the car.
2010 (and probably 2009) cars don't have the black inner trim and the mirror motor is different. The rest is the same.
Turn signal in the side view mirror replacement
Remove the 2x T10 torx screws holding the turn signal to the metal assembly (two blue arrows below). If you have a passat they're phillips screws. A long thin screwdriver can work around the motor if it's still in place.
Pull the turn signal plug out (don't pull plugs by their wires, grasp the plug) and you now have access to the 2x T10 screws or phillips screws holding the turn signal to the base. The turn signal also has a little hook halfway between the arrows (visible below). Make sure to release it and the turn signal will effortlessly come off.
Here is another picture of the turn signal and side view mirror cover which shows how they fit together. Installation is the reverse of disassembly.
Another way to replace the signal without removing the mirror glass/plastic (MK5 jetta at least): requires a long (maybe 4"), thin t10 screwdriver to reach behind the mirror glass.
Remove the mirror housing cover (at the right of the mirror ) by prying the front and back off from below. Behind the glass, on the floor of the aluminum frame, are 2 torx screws which attach the black plastic mirror housing floor (at the left of the picture above). Remove these and the floor/signal assembly will come off. Remove the torx screws at the front of the housing floor and pry open the spring clip to remove the turn signal assembly. My turn signals failed from corrosion between the harness and contacts in the assembly, possibly because the housings were cracked allowing moisture in. I cleaned the harness and put new turn signal assemblies in. I sealed one of the harness housings with dielectric grease, to see if it outlasts the unsealed side. Reassembly is the reverse. Don't overtighten the torx screws; the plastic is the cheap hard stuff that seems like it will crack over time. I took my time with this job b/c I was afraid of cracking the plastic.