P3053 Starter

[MyDimeIsUp]

EDIT: Now I can't even start the car. It cranks once and then stops. Out of the 7 times I tried to start it, it only started once. Starter spins but likes to give out shortly after.

Hello all,

I just did my passenger side motor mount and was out to get some tools today. When I got back to the car and tried to start it it cranked once and then stopped. Tried again and started up fine with an EPC light. Scanning I found P3053. I cleared the code, went home and did an oil change. Started the car back up and it started but I could tell the starter stopped earlier than it should've, and I got an EPC with P3053. The only thing I can think of is that when I was doing the passenger side motor mount that I loosened a ground wire just slightly. I tightened it back up before I did my oil change today but as stated after the oil change the EPC light came back on.

I didn't disconnect the battery when loosening the ground yesterday. Could I have fried the motor? I doubt it since it will still spin. I also moved the cables around a lot when trying to get the motor mount in, could I have stretched the wires? I'm at a loss atm.

Photo of the ground wire.





Thank you

[MyDimeIsUp]

I watched this video and they said it was the ECU. Same exact thing where the starter cranks very shortly but gives out. It is a TDI though. Crossing my fingers I haven't fried my ECU/starter just by loosening the ground a tiny bit.

https://www.youtube.com/watch?v=X-cZ...HumbleMechanic

[Smac770]

Check for 12v at the T5l plug right behind the TV22 jump start block in the plenum chamber. The ECM controls the starter relays to pass 12v from the battery through the relays, down the larger wire on that plug, to the starter, which commands it to activate.

12v should be present while you're cranking until the engine starts.

[MyDimeIsUp]

Check for 12v at the T5l plug right behind the TV22 jump start block in the plenum chamber. The ECM controls the starter relays to pass 12v from the battery through the relays, down the larger wire on that plug, to the starter, which commands it to activate.

12v should be present while you're cranking until the engine starts.

Do you have a photo for this? I have all erWin documentation but can't find any PDFs on electrical breakdowns. Thank you.

Also the car seems to be starting more often now but will still crank and then stop sometimes. I found the two triple squares for the engine mount bracket to be loose (I never tightened them fully) but highly doubt this has anything to do with it. I also cleaned the ground cable with a brass wire brush and said a couple of prayers.

This is what I have.


Thank you

[MyDimeIsUp]

Also it seems that the car doesn’t start when I just push the key with my foot on the brake. If I put my foot on the brake and push the key in the dashboard slot and then let go once it started seems to work. Idk if this is gives much info. EPC light stays on but it seems by pushing the key til it’s done cranking rather then just pushing it in and releasing immediately seems to start the car.

[Smac770]

Why I prefer complete DTC text.

P3053 00 starter activation return message terminal 50 short to ground/open circuit.

Much more clear. Because term 50 is the wire I said you should check.

So somewhere, somehow, the wire from the starter relays to the starter is shorted to ground. The ECM knows this because the ECM is connected to that starter relay output so it knows when the starter is actually being activated (so it knows to send fuel, spark, etc).

plug T5l starter side 1 resize.jpg

You see it up against the plenum chamber wall there. The larger red wire, not the two little ones. Unplug that thing. Check for voltage from positive jump start post to the pin and see if it reads 12v to either plug connector. If so, that'll tell you down which cable is the short to ground. But the error message also implies the possibility of open circuit. But to really check that, you'd need to be able to access the term 50 connection at the starter. Under the motor mount bracket.

[MyDimeIsUp]

Why I prefer complete DTC text.

P3053 00 starter activation return message terminal 50 short to ground/open circuit.

Much more clear. Because term 50 is the wire I said you should check.

So somewhere, somehow, the wire from the starter relays to the starter is shorted to ground. The ECM knows this because the ECM is connected to that starter relay output so it knows when the starter is actually being activated (so it knows to send fuel, spark, etc).

plug T5l starter side 1 resize.jpg

You see it up against the plenum chamber wall there. The larger red wire, not the two little ones. Unplug that thing. Check for voltage from positive jump start post to the pin and see if it reads 12v to either plug connector. If so, that'll tell you down which cable is the short to ground. But the error message also implies the possibility of open circuit. But to really check that, you'd need to be able to access the term 50 connection at the starter. Under the motor mount bracket.

Gotcha thank you. Which slot is the ground that I should attach my multimeter to or can I just put my positive in the plug and the negative on the ground post by the strut tower housing? And again afaik if I push and hold the key the car seems to always start. If I just push the key and release immediately that's when it seems to turnover once and then give up. Idk if that means anything or not.

[Smac770]

Put the positive on the positive jump start post and the negative on the pin 1 of the plug, one side first then the other. See if either side of that plug (ie, the male connector going one way, the female connector going the other way) causes a 12v reading. It shouldn't cause any reading. But if you're reading 12v from jump start post to either pin, then that wire is shorted to ground somewhere.

Yeah, holding the key in means the ECM just holds the line high, and the short to ground is "brute forced through" to keep the starter spinning. But you'll likely burn out the relays at some point.

But see if either side seems shorted to ground or not first.

[MyDimeIsUp]

Put the positive on the positive jump start post and the negative on the pin 1 of the plug, one side first then the other. See if either side of that plug (ie, the male connector going one way, the female connector going the other way) causes a 12v reading. It shouldn't cause any reading. But if you're reading 12v from jump start post to either pin, then that wire is shorted to ground somewhere.

Yeah, holding the key in means the ECM just holds the line high, and the short to ground is "brute forced through" to keep the starter spinning. But you'll likely burn out the relays at some point.

But see if either side seems shorted to ground or not first.

Awesome thank you. I just tested with my positive on the jumper box post and the negative on slot 1 of the female connector and I'm getting 12.42. Afaik with the male connector from the ECU it seems to be good at 0V (I had to improvise and stick a staple in slot 1 and push it against the metal and then put my multimeter probe on that staple. Either way the 12.42 is grounding on the female to starter wiring). So seems that the problem is from the female connector down to the starter motor and the ECU and starter relay are ok?

I found this in "Basic Equipment" pdf page 68 in the pdf, chapter/section 3/5. Seems all I need to do is trace T5l down down to the starter which is labeled as B and see if the wire is contacting earth/grounding somewhere on the chasis? Out of curiosity between T5l and the starter(B) what is the "2.5 rt/sw"? Is that just labeling for the wire color and Metric MM2? https://i.imgur.com/ntdDTcA.png

Also I found this which you posted before which was really useful: https://www.audizine.com/forum/attac...8&d=1573159978

[Smac770]

2.5mm² wire cross section size, red with black stripe

Actually, a voltage drop to the starter would be fine, that's the way you want the voltage drop going. If the relays applied 12v to the wire and there was no path to ground, there would be no current flow and no action at the starter. I measured mine, and I see the same. B+ towards the starter, nothing towards the relays. If it was just a voltage sense circuit, it wouldn't need a large wire to pass a lot of current. But it seems like the starter is made such that it needs some kind of jump start current flow, not just seeing 12v present.

(skip to *ABC* below, then read from here if you want)

I then changed it to resistance measurement and measured the resistance from the T5l blade (man that thing is recessed in there) to the negative jump start post. I measured nearly no resistance. I crossed my probes to see what the probes alone measured, about 1Ω. Then I connected them to the positions and it was also about 1Ω. Meaning the path from the T5l blade to the negative jump start post was adding practically no additional resistance.

That the issue started after the motor mount work, it's more likely something is up at the motor mount / starter end than an unrelated issue at the relays end just showing up at this time. But the unexpected is always an Audi perk.

So I'm not really sure, the P code is not particularly helpful, like most automotive industry codes. Found another thread where it was the wire from the relays back to the ECM (so the ECM knows the relays are powering the starter). But I don't know why you'd suddenly have issues inside the ECM box.

If you check the image you linked, the ECU pins. The ECU grounds the two top pins to activate the two relays. The result should be 12v passing through to T5l, which the ECM monitors with the connection to the third pin. The DTC is basically saying the ECM is not seeing the 12v present on that third pin.

*ABC*

Ok, here's an oddity. So you have the image I made for the B8.0 CAEB engine. When I look at the B8.5 version, there's an oddity with the wiring diagram. It has that connection direct to ECU /74 as it was in B8.0. But then it also shows it connected to /74, again, but through fuse 9 in the ECM box.

Check fuse 9 in the ECM box.

[MyDimeIsUp]

-snip- View next reply

[MyDimeIsUp]

Gotcha. I assumed 12v down that female connector was right because obviously when current is supplied it should go down so I wanted to confirm because you said it should read 0v for both sides of the connector. I was a little confused.

Also fuse 9 was blown so I put the new fuse in. First time it didn’t start. Every time after that it started and the EPC light no longer illuminated. Obviously fuses don't blow willy-nilly for no reason. Something obviously caused more amps to be sent down that line. Maybe it was just me really jiggling that ground wire around to get the motor mount in or me jacking the engine up may have really moved a cable the wrong way. Hopefully it was a one-time occurrence due to the work I was doing. Will keep posted but if this $0.30 5amp fuse was the fix I’ll be as happy as a pig in mud. Smac thank you for you’re continued info on this.

I’ll keep posted.


Also slightly off topic. The little mat/heat carpet that goes above the motor mount (pictured below) tore off for me. The motor mount is completely exposed to the heat of the exhaust. Is there really going to be abnormal accelerated wear without that heat carpet? It seems that carpet was attached to heat shielding that's bolted to the side of the engine and requires the cat to be removed and a bunch of other work which isn't worth it for a $30 heat-insulating carpet.

[Smac770]

It's part 7 here: https://audi.7zap.com/en/usa/audi+a4.../1/199-199010/
As seen here: https://autopublic.org/en/carpart/8k...-AP1623322395#
Or here on the bracket: https://www.ebay.com/itm/294638213722

How much issue with the heat make for the rubber in the engine mount; I have no idea. It certainly doesn't seem like much protection for anything.
You can see the three bolts that hold it on in the eBay images. I don't think that would be fun to try with the turbo and cat in place. But probably doable if you back the cat off the turbo, such as if you were inspecting the wastegate. I'd wait till you had a reason to lift the car and then hit it then.

[MyDimeIsUp]

It's part 7 here: https://audi.7zap.com/en/usa/audi+a4.../1/199-199010/
As seen here: https://autopublic.org/en/carpart/8k...-AP1623322395#
Or here on the bracket: https://www.ebay.com/itm/294638213722

How much issue with the heat make for the rubber in the engine mount; I have no idea. It certainly doesn't seem like much protection for anything.
You can see the three bolts that hold it on in the eBay images. I don't think that would be fun to try with the turbo and cat in place. But probably doable if you back the cat off the turbo, such as if you were inspecting the wastegate. I'd wait till you had a reason to lift the car and then hit it then.

Exactly. I've had this thing up on jack stands for the past 2 - 3 days between the motor mounts, tune-up with oil change, spark plugs and air filter, and now this whole debacle.

I know its a long shot but what do you think could've caused this? The circuit schematic seems pretty simple to me so I don't see what could've caused the short. Obviously I'm not looking to go full NTSB mode to find exactly when, where, and why the short happened but more just interested in a theory. Only thing I've done is jack the engine up and pick up slack with engine support beam, loosen the nut that holds that ground wire in slightly and jiggle it around to get the motor mount in, and that's it.

[Smac770]

I don't think messing with the engine ground strap would have impacted it. I don't really know. You figure 12v shows up on the line from the relays. The current goes to the starter and goes to the ECM, though much less should go to the ECM because it's just sensing the voltage and should have large input impedance (should). To blow the fuse, there would have to have been some issue that presented a shorting along that wire from the fuse 9 to the ECM pin 74. Got me.

[MyDimeIsUp]

I don't think messing with the engine ground strap would have impacted it. I don't really know. You figure 12v shows up on the line from the relays. The current goes to the starter and goes to the ECM, though much less should go to the ECM because it's just sensing the voltage and should have large input impedance (should). To blow the fuse, there would have to have been some issue that presented a shorting along that wire from the fuse 9 to the ECM pin 74. Got me.

Awesome thank you for this. I'm reading through the "Basic_equipment_From_September_2007.pdf" pdf now and I'm actually in the right chapter/section now (No. 119). However reading this thing is an absolute mess. Its got J623 stretched out on 18 pages (yes I counted) and I can't even see how SB9 plays its part in preventing the starter. Are you actually following this PDF or are you using some type of software/web app that lays out the entire No. 119 chapter out? Maybe something like this: https://www.youtube.com/watch?v=nVjt...rioDiagnostics

[Smac770]

No, I use the PDF. It's clear to me. But I've used the document a lot in the past few years. I've made a index listing with all the sections so I can fast look through it for what section might be relevant to my interest, etc.

So page 119/4 (assuming this is the 09.2012 document version, which is what I have), we see the starter, B. And the term 50 connection, which is a 2.5 red/black wire. That goes to [57], meaning go over to column 57 to continue following the wire. The column numbers are across the bottom of the diagrams. We find [57] on page 119/6. Where we see a 2.5 red/black connection to [33]. If we look back at /4, we see, yep, that was in column [33]. So that's how the pathing across pages is annotated.

Now the problem is the diagram on /6 is still showing the B8.0 path of T5l/1 to T94/74 via D97. That's not actually there on B8.5. So that's a defect in the drawing. Instead, we see the wire go up to [61], which goes over and we see it come in above SB9. The wire passes through SB9 and then goes to T94/74 via either direct wire if *5 (without stop/start) or via a connection to D210, which joins to a wire to the J532, if *4 (with stop/start). And the * next to the J532 identifying the voltage stabilizer device as also only if with stop/start.

So see, easy as pie. :-D

(note, D97 still exists, as it connects the three wires from the T5l/1, from the SB9, and from the J53 relay output together, just that wire directly from D97 to T94/74 does not exist in B8.5)

Also, on the fuses notation, it kind of sucks. So "ST1 SB9", that means fuse panel B ("SB", in the ECM box), fuse row 1 ("ST1"), fuse 9. Who came up with that convoluted syntax, I have no idea.

[MyDimeIsUp]

No, I use the PDF. It's clear to me. But I've used the document a lot in the past few years. I've made a index listing with all the sections so I can fast look through it for what section might be relevant to my interest, etc.

So page 119/4 (assuming this is the 09.2012 document version, which is what I have), we see the starter, B. And the term 50 connection, which is a 2.5 red/black wire. That goes to [57], meaning go over to column 57 to continue following the wire. The column numbers are across the bottom of the diagrams. We find [57] on page 119/6. Where we see a 2.5 red/black connection to [33]. If we look back at /4, we see, yep, that was in column [33]. So that's how the pathing across pages is annotated.

Now the problem is the diagram on /6 is still showing the B8.0 path of T5l/1 to T94/74 via D97. That's not actually there on B8.5. So that's a defect in the drawing. Instead, we see the wire go up to [61], which goes over and we see it come in above SB9. The wire passes through SB9 and then goes to T94/74 via either direct wire if *5 (without stop/start) or via a connection to D210, which joins to a wire to the J532, if *4 (with stop/start). And the * next to the J532 identifying the voltage stabilizer device as also only if with stop/start.

So see, easy as pie. :-D

(note, D97 still exists, as it connects the three wires from the T5l/1, from the SB9, and from the J53 relay output together, just that wire directly from D97 to T94/74 does not exist in B8.5)

Also, on the fuses notation, it kind of sucks. So "ST1 SB9", that means fuse panel B ("SB", in the ECM box), fuse row 1 ("ST1"), fuse 9. Who came up with that convoluted syntax, I have no idea.

My revision is 10.2014 as is marked in the bottom right but mine is the exact same and your explanation made sense. Still a cluster of electrical schematics but it makes sense and I was able to follow. So what you're saying is that on /6 for column 57, since I have a B8.5 the wire actually never connects to D97? Basically just imagine that the D97 connection isn't there and the wire runs from 57 to 61 without anything (D97) butting in?

[Smac770]

Section	PDF page	Description	Date	Comment
1	1	Standard Equipment	from Sept 2007	original B8
2	35	Convenience System	from Sept 2007
3	64	Fuse Positions	from Sept 2007
4	96	CAN disconnect plug	from Sept 2007
5	105	CVT transmission 0AW	from Sept 2007
6	110	ZF6 transmission 0B6	from Sept 2007
7	115	Cell phone prep (MOST bus) - USA	from Sept 2007
8		3.0 TDI V6 - CAMx, CAPx	from Sept 2007
9	118	Active steering (dynamic steering)	from Sept 2007
10	122	3.2L V6 - CALA	from Sept 2007
11	151	Data bus OBD interface	from Sept 2007
12		1.8T I4 - CABx, CDHx	from Sept 2007
13	155	HID headlamps with auto range ctrl	from Sept 2007
14	161	Coolant fan 400W (I4/V6 gas)	from Sept 2007
15	163	Coolant fan 600W (I4/V6 gas)	from Sept 2007
16		Coolant fan 400W (I4/V6 diesel)	from Sept 2007
17		Coolant fan 600W (I4/V6 diesel)	from Sept 2007
18		Coolant fan 800W/1kW (V6 diesel)	from Sept 2007
19	165	Coolant fan 800W/1kW (V6/V8 gas)	from Sept 2007
20	167	Park distance control with no park assist steering (park assist)	from Sept 2007
21	171	Airbag systems	from Sept 2007
22	182	Rearview camera system (rear assist)	from Sept 2007
23	186	Adaptive suspension w/ adjustable dampers	from Sept 2007
24	193	Electromechanical parking brake	from Sept 2007
25		Trailer coupling	from Sept 2007
26	197	HID with auto range ctrl and cornering lamp	from Sept 2007
27		Auxiliary heater	from Sept 2007
28	204	Garage door opener	from Sept 2007
29	206	Heated seats	from Sept 2007
30	211	Front seats adjustment	from Sept 2007
31	218	Driver seat with memory, lumbar, ventilation, heating	from Sept 2007
32	226	Power lumbar support for manual seats	from Sept 2007
33	229	Multifunction steering wheel	from Sept 2007
34		Cell phone prep (CAN bus) - RoW	from Sept 2007
35		Cell phone prep (MOST bus) - RoW	from Sept 2007
36	233	Bluetooth telephone (MOST bus)	from Sept 2007
37	236	Cell phone prep without hands-free system (CAN bus)	from Sept 2007
38	238	Cell phone prep without hands-free system (MOST bus)	from Sept 2007
39	241	Automatic climate control (Comfort Climatronic)	from Sept 2007
40	251	Automatic climate control (Basic Climatronic)	from Sept 2007
41	258	Ring break diagnosis	from Sept 2007
42	261	Infotainment MOST bus	from Sept 2007
43	265	ABS with ESP	from Sept 2007
44	273	MMI Basic	from Sept 2007
45	277	CD/DVD changer (MOST bus)	from Sept 2007
46	279	MMI with digital radio	from Sept 2007
47	281	MMI with radio and basic sound system	from Sept 2007
48	285	MMI with radio and standard sound system	from Sept 2007
49	290	MMI with radio and B&O sound system	from Sept 2007
50	297	Cell phone prep (CAN bus) - USA	from Sept 2007
51	302	MMI high with navigation system	from Sept 2007
52	304	MMI high	from Sept 2007
53	308	MMI high with radio	from Sept 2007
54		MMI high with TV tuner	from Sept 2007
55	310	MMI high with satellite radio	from Sept 2007
56	312	Radio with basic and basic plus sound system	from Sept 2007
57	321	Radio with standard sound system	from Sept 2007
58	331	Radio with B&O sound system	from Sept 2007
59	343	Interior mirror, no humidity sensor, no high beam assist	from Sept 2007
60	346	Interior mirror, with humidity sensor, no high beam assist	from Sept 2007
61	349	Interior mirror, with humidity sensor, with high beam assist	from Sept 2007
62	352	Tire pressure monitoring	from Sept 2007
63		2.0 TDI I4 - CAFA, CAGx, CAHx, CMEA	from Nov 2007
64	354	2.0T I4 - CAEx, CDNx, CDZA	from May 2008
65	376	Lane departure warning (Lane Keep assist)	from Sept 2007
66	379	Lane change assistance (Side assist)	from Sept 2007
67	383	Special functions interface	from Sept 2007
68	386	Seat ventilation with heated seats	from Sept 2007
69		Communications - Japan	from Jan 2008
70	391	Lid and tail lamps, Avant	from Jan 2008
71	399	Antennas, Avant	from Jan 2008
72		Driving school	from Jan 2008
73		Investigation / civil response vehicles	from Jan 2008
74		Emergency response vehicles (police, fire, medical)	from Jan 2008
75		Prep for driving aids for disabled persons	from Jan 2008
76		Rental / taxi vehicle special equipment	from Jan 2008
77	406	Adaptive cruise control	from Sept 2007
78		3.0 TDI V6 - CAMA, CCWx, CGKx	from May 2008
79	408	Sunroof (open sky system)	from May 2008
80	411	Cell phone prep (CAN bus)	from May 2008
81	416	Cell phone prep (MOST bus)	from May 2008
82	420	3.0T V6 - CAKA, CCBA, CGXC, CLUA	from Nov 2008	supercharged S4
83	445	MMI with radio and basic sound system	from Sept 2008	switch from MMI 2G to 3G (US MY10)
84	451	MMI with radio and standard sound system	from Sept 2008
85	457	MMI with radio and B&O sound system	from Sept 2008
86	465	MMI (information electronics 1)	from Sept 2008
87		TV Tuner (MOST bus)	from Sept 2008
88	475	Cell phone prep (MOST bus) - USA	from Sept 2008
89	479	Cell phone prep (MOST bus)	from Sept 2008
90	484	Bluetooth telephone (MOST bus)	from Sept 2008
91	489	Cell phone prep without hands-free system (MOST bus)	from Sept 2008
92	492	Ring break diagnosis	from Sept 2008
93	494	Infotainment MOST bus	from Sept 2008
94	496	CD/DVD changer (MOST bus)	from Sept 2008
95	498	DSG transmission 0B5	from Sept 2008
96	505	Rear final drive - sport diff	from Sept 2008
97	512	Multimedia system prep	from Sept 2008
98		3.0 TDI V6 - CCLA	from Nov 2008
99	514	LED tail lamps, Sedan	from Sept 2008	US MY10 option
100	517	Lid and LED tail lamps, Avant	from Sept 2008	no B8.0 avant LED in US
101	525	Antennas, Avant	from Sept 2008
102		Driving school	from May 2009
103		Investigation / civil response vehicles	from May 2009
104		Emergency response vehicles (police, fire, medical)	from May 2009
105		Prep for driving aids for disabled persons	from May 2009
106		Rental / taxi vehicle special equipment	from May 2009
107	531	Fuse Positions	from May 2009	US MY10
108		Start/stop system	from May 2009	not on US models
109		2.0T I4 with start/stop - CDNx, CFKA	from May 2009
110		2.0 TDI I4 with start/stop - CAGx, CAHx, CMEA, CJCB	from May 2009
111	565	ZF8 transmission 0BK/0BL	from May 2010	switch from 6AT to 8AT (US MY11)
112	570	Standard Equipment	from Nov 2011	B8.5 (US MY13)
113	604	Comfort System	from Nov 2011
114	634	Fuse Positions	from Nov 2011
115		1.8T I4 - CCUA, CJEx	from Nov 2011
116		2.0 TDI I4 - CGLx, CJCx, CMFA	from Nov 2011
117	672	3.0T V6 - CGWC, CGXC, CHMB, CMUA, CTUB	from Nov 2011
118		3.0 TDI V6 - CDUC, CKVx, CLAB	from Nov 2011
119	697	2.0T I4 - CADA, CAEx, CDNx, CDZA, CFKA, CPMx	from Nov 2011
120	722	Electromechanical steering	from Nov 2011
121	724	Interior rearview mirror	from Nov 2011
122	728	HID headlamps with auto range ctrl	from Nov 2011
123	734	Bixenon HID with auto range ctrl and cornering lamp	from Nov 2011
124	740	Park distance control	from Nov 2011
125	744	Lane assist	from Nov 2011
126	747	Lane change assistance	from Nov 2011
127	751	Adaptive cruise control	from Nov 2011
128	753	Airbag systems	from Nov 2011
129	765	Level control system with damp adj	from Nov 2011
130	772	Automatic climate control (Comfort Climatronic)	from Nov 2011
131	782	Automatic climate control (Basic Climatronic)	from Nov 2011
132	789	Electromechanical parking brake	from Nov 2011
133		Trailer coupling	from Nov 2011
134	793	Heated seats	from Nov 2011
135	798	Multimedia system prep	from Nov 2011
136	800	ABS with ESP	from Nov 2011
137	808	Seat ventilation with heated seats	from Nov 2011
138	813	LED tail lamps, Sedan	from Nov 2011
139	816	Lid and tail lamps, Avant	from Nov 2011
140	824	Lid and LED tail lamps, Avant	from Nov 2011
141		Start/stop system	from Nov 2011
142	832	Rear final drive - sport diff	from Nov 2011
143	839	Bluetooth telephone (MOST bus)	from Nov 2011
144	844	Cell phone prep (CAN bus)	from Nov 2011
145	849	Cell phone prep (MOST bus)	from Nov 2011
146	854	Radio with basic and basic plus sound system	from Nov 2011
147	863	Radio with standard sound system	from Nov 2011
148	873	Radio with B&O sound system	from Nov 2011
149	885	Structure-borne sound actuator	from Nov 2011
150	887	MMI with radio and basic sound system	from Nov 2011
151		Digital TV tuner	from Nov 2011
152	893	MMI with radio and standard sound system	from Nov 2011
153	900	MMI with radio and B&O sound system	from Nov 2011
154		Driving school	from Nov 2011
155		Prep for driving aids for disabled persons	from Nov 2011
156		Investigation / civil response vehicles	from Nov 2011
157		Emergency response vehicles (police, fire, medical)	from Nov 2011
158		Rental / taxi vehicle special equipment	from Nov 2011
159		1.8T I4 - CDHA	from Nov 2011
160	909	4.2L petrol engine, CFSA	from May 2012
161	938	Dynamic Ride Control	from May 2012
162		Investigation / civil response vehicles	from May 2012
163		Emergency response vehicles (police, fire, medical)	from May 2012
164		2.0 TDI I4 - CGLx, CJCx, CMGB, CMFx	from May 2012
165		2.0T I4 EA888 Gen III - CNCD, CUHA, CUJA	from May 2013
166		2.0 TDI I4 with start/stop - CNHx, CSUx	from Sept 2013
167		3.0 TDI V6 - CDUC, CKVx, CLAB	from May 2013
168	955	Headlamps, Bixenon HID with range and cornering, RHD	from Nov 2011
169	961	3.0T V6 evo - CREx, CTDA	from May 2014
801	942	Ground Connections, Sedan overview
	945	Ground Connections, Avant overview
	947	Ground Connections
802	964	Fuses
803	1023	Relays
804	1031	Control modules in front part of vehicle
805	1047	Control modules in interior and rear part of vehicle
806	1088	Connector stations
851	1117	Climatic / Climatronic Systems
852	1128	Anti-Lock Brake System
853	1138	Access/Start Authorization System
854	1145	Airbag Systems
855	1157	Camera System
856	1158	Engine Management Systems
857	1243	Lane Assist System
858	1246	Parking Aid Systems
859	1251	Radio / Navigation Systems
861	1265	Transmission Systems
862	1280	Tire Pressure Monitor System (TPMS), up to MY 2010		section title is wrong, MY10+ had indirect TPMS
863	1282	All-Wheel Drive System
864	1285	Central Locking / Anti-Theft Systems
866	1299	Comfort System (power seat, vent/heat, humidity sensor)
867	1309	Sunroof Systems
868	1313	Power Steering System

[Smac770]

That's a BBcode table version of the index I made from the 8K wiring schematics document. A number of the sections are not in the US version of the document since they are for components not available on AoA constructed builds.

As for the diagram, see D97. Wire goes to the right from D97, and then splits down to the relay and up to the ECM. That up wire to the ECM is on B8.0, and is not on B8.5. Instead the wire that goes left and up from D97 and over to SB9 is what is on B8.5. I suspect also maybe on B8.0 stop/start vehicles (stop/start on B8 started in CY09, but stop/start never came to US B8 models except B8.5 Q5 with specific engines).