Fuse 29 & Fuse 32 not getting power.

**8520** · 03-07-2016 09:19 PM

This is for the 2.7 swap in to my s6. Rewired body plugs on engine harness to s6 connectors and was simple enough, however, I'm not getting power at either fuse 29 or fuse 32, both of which are labeled engine control unit. My ecu is not getting power on pin 3 (black/blue) but is getting power at pin 62 (pin 21 has no wire in it so I assume it's not necessary).

I talked to mr. rictus who had the same issue with his swap, but he didn't do the wiring unfortunately :(

My first instinct says to cut the feed side of these two fuses and run them to the lugs under the dash. Anyone see any problems with this? This way they would still have their appropriate fusing, but just use an alternative power source.

Thanks.

**PaperToast** · 03-07-2016 09:47 PM

when in doubt, macgyver it

**julex** · 03-08-2016 06:50 AM

That would work I think. Do you have electric diagrams/shop manuals to trace the circuits? stratocu510 on QW can hook you up with that.

**8520** · 03-08-2016 09:13 AM

I have a Bentley, but can't seem to find mention of those fuses anywhere.

**julex** · 03-08-2016 11:23 AM

Bentley is not factory manual

. Bentley is worse than Cliff Notes of automotive world. The 01e service manual itself is thicker than whole bentley which has about 20 pages about transmission.

**8520** · 03-08-2016 11:35 AM

Perfect. Guess I'll go try and track him down.

**NuGGet_PuFFer** · 03-08-2016 11:47 AM

I went to high school with the guy (Greg aka Swoops) that did Mr. Rictus's swap/wiring/exhaust/etc. and dated his cousin back then, I could probably get you guys in touch, let me know.

**8520** · 03-08-2016 12:06 PM

I sent swoops an email last night. Hoping he'll get back to me.

After looking at the factory diagram a little bit, I don't see any issues with re sourcing the fuse feeds. Need to read them a bit more when I get home from work.

**NuGGet_PuFFer** · 03-08-2016 12:24 PM

Originally Posted by 8520

I sent swoops an email last night. Hoping he'll get back to me.

After looking at the factory diagram a little bit, I don't see any issues with re sourcing the fuse feeds. Need to read them a bit more when I get home from work.

Just spoke with him, he said he's swamped at the shop and is looking for the wiring diagrams he made during Nick's swap, and he's gonna try and email u back later. Good luck.

**Kaane** · 03-08-2016 02:46 PM

Which year ECU / Harness are you using for the engine? Into a 2002-2003 S6?

**8520** · 03-08-2016 03:12 PM

Originally Posted by Kaane

Which year ECU / Harness are you using for the engine? Into a 2002-2003 S6?

2000 a6 manual engine harness. 2002 s6 car.

**Kaane** · 03-08-2016 03:52 PM

On the 2002 Engine the power to pin 3 is supplied by the J271 ECU Relay. Which is actually controlled by the ECU itself. The 2000 Engine does not have that relay at all. So you will need to bypass it.

**Kaane** · 03-08-2016 03:57 PM

Here are the ELSA diagrams for both engines.

https://mega.nz/#!q40SQaIa!ogSotzyKC...MxeveUDwgws3SU

https://mega.nz/#!y0kyXSBC!uYg7s07Do...Y9rO28no4MOsAI

**Kaane** · 03-08-2016 04:34 PM

Looks like J271 Relay feeds Pin Connector T17i/16 white connector. Input to the J271 Relay is T10p/4 Black Connector which also feeds Pin 62 on the ECM. So make a bridge between those 2 pins and you should get power to fuse 29.

**8520** · 03-08-2016 05:30 PM

Originally Posted by Kaane

On the 2002 Engine the power to pin 3 is supplied by the J271 ECU Relay. Which is actually controlled by the ECU itself. The 2000 Engine does not have that relay at all. So you will need to bypass it.

Now that makes sense. I had pulled the j271 relay and noticed nothing seemed to trigger it. Google showed it as a relay for power fold mirrors, but the fsm I got today showed it as power for the ecm. So presumably making that relay trigger will fix one of my fuses. Perfect. Thanks.

**AudiA4_20T** · 03-08-2016 09:38 PM

Originally Posted by Kaane

Here are the ELSA diagrams for both engines.

https://mega.nz/#!q40SQaIa!ogSotzyKC...MxeveUDwgws3SU

https://mega.nz/#!y0kyXSBC!uYg7s07Do...Y9rO28no4MOsAI

Do you have Elsa for the S6 fan specific section?

**Kaane** · 03-08-2016 10:57 PM

Originally Posted by AudiA4_20T

Do you have Elsa for the S6 fan specific section?

Engine cooling fan? The engine diagrams i posted have a cooling fan section.

**8520** · 03-08-2016 11:05 PM

Well. Got those fuses sorted.

Jumped black connector pin 4 to white connector pin 16 to get fuse 29 going. Had to repin appropriate gauge wiring.

Got fuse 32 going by cutting the feed and temporarily running it to 75x.

Soooo.....

Now I have power at the ecu but it will not read through vag com and will not illuminate the cel.

Pins 3 and 62 both have 12v, pins 1 & 2 both have ground. Pin 43 at ecu, green black, k-line, shows continuity with green/red obd pin 7. Vag com works with other equipment in the car, but can't communicate with the ecu.

I'm stumped, and frustrated.

**Robsa6** · 03-09-2016 04:25 AM

I JUST and I mean JUST got my car running after doing the same (sort of) thing . Ive got an 02 A6 and swapped in a 00 A6 with the harness and all. I had to rewire the White and Red connectors but the others were fine. I didn't, however have an issue with the ECU not getting power. I don't have a wire at pin 21 either. My issue was with a red /grey wire I still have yet to find it's location and a black and violet wire from the red connector. I chased the diagrams for hours via All Data. Good luck with your swap