2016 S4 6MT trans in a 2011 S4?

Hi all,

After 105k miles, the trans in my 2011 s4 6MT started making some drivetrain noise, turns out it was coming from within the trans..

Anyways, I bought a used trans with 6k miles from a 2016 S4 rather than taking out my trans and having it rebuilt ($2k+ and a month without my car). I researched everything and couldn't find any differences so I figured it would bolt right up. I even checked ECS and Alldata for different part numbers for the clutch, axles, mounts and reverse light switch BEFORE I ordered the trans. Everything seemed to check out. When I got the trans, everything was the same as my 2011 trans except for one thing.. The reverse light switch. My 2011 trans has an actual mechanical style switch (part number: 0B1941521B) and the 2016 has a hall effect style sensor, (part number: 0B3927753A). This is leaving me without reverse lights or a backup camera. I can't find any info on Alldata or online for this updated reverse light switch.

A pigtail was spliced into my harness to try and see if the new sensor would work with my existing wiring since both sensors are 3 wires.. It doesn't.

Does anyone know if it's possible to code my computer so the car will work with the new style sensor or have a work around for this?

Thanks!

In the 2016 there is a Gear Recognition Sensor (G604). Pin 2 of that goes to Engine connector T94, pin 34.
G604 pin 1 is 5V supply, pin 3 is GND.

The 2011 has a F208 Transmission range gear recognition switch that goes into J519 (the central electrics) T32b/13 (F208 pin 1) and T32b/21 (F208 pin 2). Pin 3 of F208 is GND. I couldn't find an assignment for engine pin T94/34 in the 2011.

So that's quite the major difference there... not sure where you go next. Manual switch to simulate the F208, microswitch at your gear lever?
What happened to your transmission? Was the fluid ever changed?

Eric said:

In the 2016 there is a Gear Recognition Sensor (G604). Pin 2 of that goes to Engine connector T94, pin 34.
G604 pin 1 is 5V supply, pin 3 is GND.

The 2011 has a F208 Transmission range gear recognition switch that goes into J519 (the central electrics) T32b/13 (F208 pin 1) and T32b/21 (F208 pin 2). Pin 3 of F208 is GND. I couldn't find an assignment for engine pin T94/34 in the 2011.

So that's quite the major difference there... not sure where you go next. Manual switch to simulate the F208, microswitch at your gear lever?
What happened to your transmission? Was the fluid ever changed?

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Awesome, that's the information I was looking for. For whatever reason, alldata does not have any electrical diagrams for the 2016. I will probably have to rig something up with the old sensor and get it to work that way. I have a short shifter to install anyways, so I will figure it out then.

As far as the fluid goes, I have changed the fluid 3 times since I bought the car in 2014 with ~50k miles. The fluid was always clean and free of debris/metal. I have never launched the car or taken it to any kind of track. It's my daily commuter.

It has had AWE stage 2 for almost all of my ownership, but that's it. Oddly enough there was another b8 s4 6MT at the shop for a trans replacement when I took my car in.

The trans shifted perfectly even when it was making noise. No grinds, lockouts, pop-outs etc. I will pull the trans apart this winter and see what the culprit was.

rr8rs said:

Oddly enough there was another b8 s4 6MT at the shop for a trans replacement when I took my car in.

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Was that stock, or had it been tuned also? I'm wondering if the 6MT is marginal on torque rating which is exceeded when tuning?

PetrolDave said:

Was that stock, or had it been tuned also? I'm wondering if the 6MT is marginal on torque rating which is exceeded when tuning?

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The other b8 was not stock, but I cannot comment on the extent of modifications. It was a stage 2+ car I believe.

rr8rs said:

The other b8 was not stock, but I cannot comment on the extent of modifications. It was a stage 2+ car I believe.

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So two B8 S4s in the same shop with 6MT issues, one Stage 2 tuned and the other Stage 2+ tuned???

I'd start doing some digging to see what the torque capacity of the 6MT transmission is, and what Stage 2 & Stage 2+ do to the torque output of the engine - seems too much like coincidence to me.

Max torque doesn't jump too much on those supercharged engines, they just rev them higher with higher torque. APR goes from 350 ft lbs to 395ft lbs with a single pulley on 98 RON. 428 ft lbs with dual pulleys though.
When mated to the 3.0TDi the 0B4 accepts 500Nm or 368 ft.lbs . That's the official published number, but then again Audi publishes 325 ft lbs and APR measured 350 stock on the S4.

Eric said:

428 ft lbs with dual pulleys though.
When mated to the 3.0TDi the 0B4 accepts 500Nm or 368 ft.lbs.

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428 > 368

Eric said:

Audi publishes 325 ft lbs and APR measured 350 stock on the S4.

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Pretty normal for most manufacturers to underquote to allow for production tolerances.

PetrolDave said:

So two B8 S4s in the same shop with 6MT issues, one Stage 2 tuned and the other Stage 2+ tuned???

I'd start doing some digging to see what the torque capacity of the 6MT transmission is, and what Stage 2 & Stage 2+ do to the torque output of the engine - seems too much like coincidence to me.

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I'm not worried about it. I'd be concerned if my car had 20k miles, but it has almost 106k. The used trans I got has 100k less miles and came with a like new oem clutch and flywheel so the cost to replace the entire transmission wasn't really anymore than just replacing the clutch. I'm sure I can figure out a work around for the reverse lights, but it would've been convenient if I could just program the existing module to accept a hall signal.