B8 S5 Clutch Position Sensor Wiring

[Max B8]

Hello all, looking at this wiring diagram, trying to figure out where pin 2 for the clutch position sensor goes to, only thing it gives me is “18” and never is referenced again. Any ideas? Thank you.

[hahnmgh63]

It looks like the Green/Grey splits and goes to pin #15 at the ECU and to a Blue/Black wire pin #11 at the ECU. When I say split, it goes to a plug, a 17pin Red connector that should be in the front left side of the ECU box. What year is your B8? Looks like all years of the B8 go to the 17pin Red connector but depending on the year they may connect to different pins on the ECU. Late B8 Green/Grey may go to pin #43 after the 17pin plug while the Blue/Black may go to pin #20.

[Max B8]

It looks like the Green/Grey splits and goes to pin #15 at the ECU and to a Blue/Black wire pin #11 at the ECU. When I say split, it goes to a plug, a 17pin Red connector that should be in the front left side of the ECU box. What year is your B8? Looks like all years of the B8 go to the 17pin Red connector but depending on the year they may connect to different pins on the ECU. Late B8 Green/Grey may go to pin #43 after the 17pin plug while the Blue/Black may go to pin #20.

That's confusing. I have a 2010 4.2l S5, and I followed the GRN/GRY 18 from page 25 where it leads to the other side of the page labeled 24, then again on another page it comes out and goes to pin 41 on the ECU. Is this incorrect?

[hahnmgh63]

I'm showing the Green/Grey going to pin #63 on the big 94 pin connector and Blue/Black which also ties into the Green/Grey at the 17pin Red connector going to what's called connection 12 in the Engine compartment wiring harness and from there going to pin #42 at the ECU 94 pin connector. This diagram says for cars built from 12/2009. If you want to send me your email address I'll send you a pdf of the page. The total schematic is 41MB so my two email accounts have a 25MB limit.
Some pages of the wiring diagram don't seem to jive but the only one I found with the Green/Grey wire going to pin #41 was a later B8.5 A5 with the ZF 8HP. Since your car is a 2010 and some changes were made in mid to late 2009 the month of construction will matter. At least it looks like the wiring colors have stayed the same, just the ECU pin connectons have changed. So the ECU must have been updated around '09~'10 and caused a pin change for some of the connections, then again not surprisingly with the B8.5 A5's.

[Smac770]

Looking at the wiring diagram for a type 8T with a CAUA with 6MT (0B4):
G476 6-pin, pin 2 > green/gray > red 17-pin, pin 9 > green/gray > ECM 94-pin, pin 41

The "other" wire is:
G476 6-pin, pin 3 > blue/gray > red 17-pin, pin 12 > blue/gray > ECM 94-pin, pin 39

The blue/black from ECM 94-pin, pin 39 to red 17-pin, pin 9 and the blue/gray passing through red 17-pin, pin 12 (no connection to the ECM in this config) would be for the 6AT (0B6), where there would be no G476.

I don't know what reference has a green/gray to ECM 94-pin, pin 63. You can search the wiring diagrams PDF for pin positions if you put a space before the slash. Such as T94 /63.

[hahnmgh63]

The one I mentioned where I see it going to Pin 41 I'm seeing on sheet 9/24 showing a date of 12.2014, wouldn't that be for a mid B8.5 change? Maybe I need to re-read the Audi wiring diagram legends to see what the significance of that date is?

[Smac770]

Section 9, page 24 of the 8T (B8 A5 coupe/sportback) wiring diagrams is for the CAUA "from Jun '07". But we see there's a later CAUA section, section 87, for "from May '08".

So section 9 is only for MY08, section 87 would be for MY09+. The dates on the sections are not indicative of their subject material; simply when they were last changed.

Pin 41 is the correct pin, and what all the diagrams showed for the CAUA. You had typed "Green/Grey going to pin #63 on the big 94 pin", and that's what didn't make sense to me. But I see now that's in reference to the 3.0 TDI (section 8). So that's just from looking at the wrong section.

I really hate Audi USA deleting content from the wiring diagrams. Need to find a new erwin.audi.com solution to get proper full world wiring diagrams. Luckily, it seems the old 8T copy I have is a full world version. Because searching the more recent 8T document from audiusa came up with nothing about green/gray on T94/63, because all the TDI sections were deleted.

[Max B8]

After putting everything back together and wiring it the way I showed https://imgur.com/a/fMFe9Jz (connector pinout) and the clutch isn't able to be located on VCDS, so I am not sure what has to be corrected.

[Max B8]

Also thus I am getting no crank but everything else works, it is frustrating cause of how close I feel I am. Additionally, I sent my ECU out to be reflashed so now it is basically a stock manual b8 s5 ECU, tune will come after I get crank.

[Smac770]

"the clutch isn't able to be located on VCDS", I'm not sure what that's suppose to mean. Are you looking at some measuring value in the 01-engine for clutch status and not seeing it transition as you press the clutch?

[Max B8]

Sorry for the poor wording, but yeah, I went to control modules > drivetrain > clutch and it couldn't locate the clutch, much less do an output test.

[hahnmgh63]

Trying to remember if you had another thread going, was this a Auto to Manual conversion? I think you have to recode the car from an Auto to a Manual under the Instruments module but there won't be a Clutch module since it is fully mechanical. On the B8 there may be other modules to code, Central Convenience, possibly ABS, Acc/Start, Can Gateway, and maybe Steering wheel if it has Tip buttons.

[Smac770]

There's no control module for "clutch". Always only work from the Installed and Installed2 lists; the rest of the tabs include many more control module addresses not relevant to that vehicle type, and maybe even more that are not relevant to your specific vehicle (for example, 02-auto trans is relevant to 8K/8T, but not relevant to one with a 6MT).

If there's any form of clutch depressed/released status to review, it'll be in the measuring values of the two control modules that monitor the clutch pedal position sensor: 01-engine (J623) and 46-central convenience/comfort (J393).

[SALWITDAB7]

Can someone help me ? Just did a 6M/T swap on my A4 b7. I got everything switched out . I'm stuck at clutch switch wiring. I don't kno how to