Fusebox internals - map/diagram

John Cody Forbes cody at 5000tq.com
Sat Sep 25 08:22:41 PDT 2010 

Just use a logic probe to back probe the coil connector for checking for spark. If the signal is getting to the coil then the ECU is doing it job as well as the POS's.

-Cody (mobile)

On Sep 25, 2010, at 9:38 AM, "Ben Swann" <benswann at verizon.net> wrote:

> Spark testing on Coil on Plug engines where plugs are under sealed cover is not as
> trivial as on the earlier engines with exposed wires - but there are ways I can try.  If
> the injectors are triggered and fuse to the ignition coil packs is getting power then
> one may presume spark.  I don't think this is the problem unless part of a bigger
> problem.
> 
> I do plan to provisionally wire everything hot to verify it is something in the way the
> relay is wired. 
> 
> All the wiring looks great, so beginning to think it may even be the ECU.  The ECU
> starts toggling the internal relay rapidly after being powered on for awhile.
> 
> Ben
> 
> -----Original Message-----
> From: Huw Powell [mailto:audi at humanspeakers.com] 
> Sent: Saturday, September 25, 2010 2:23 AM
> To: Ben Swann
> Cc: quattro at audifans.com; '200q20V mailing list'
> Subject: Re: Fusebox internals - map/diagram
> 
> 
> 
> On 9/24/2010 7:55 PM, Ben Swann wrote:
>> Huw your diagram is very useful even if it is not 100% accurate for the later fusebox!
> 
> Thanks, glad it helped in any way.
> 
>> I located the original problem in question - I had installed the main 
>> power lead that should have gone to an L30 termanal on the N terminal 
>> - this is a normally unconnected terminal.  Now I have ECU power.  All 
>> power is now toggled on with ignition switch so progress.
> 
> Excellent.
> 
>> The problem I am having now is that the fuel pump relay does not 
>> trigger on despite verification of good hall signal and new flywheel 
>> sensors in place.  I verified the FP relay clicks while turning the 
>> crank by hand  - hall going in/out of window, but for some reason the 
>> pump does not come on.  I verified connectivity to the pump by bridging 30 to 87 and
> Fuel pump runs and I set the fuel pressure.  I put the correct relay in.
>> 
>> It sounds like injectors are clicking and/or spark plugs igniting, but 
>> no pump while cranking.  I have yet to pull codes with VAG COM, but 
>> there should be no reason not to be getting good signal sync. -  new 
>> flywheel sensors and flywheel pins in place and everything is factory clean.
> 
> So why not crank it with the FPR jumped?  Have you tested for spark? 
> Surely you have one of those $10 neon thingies for that?
> 
>> I tried different FP relays including the original 7A relay that is 
>> also used in 3B and other engines 8A0 951 253 L.
>> 8A0 951 253 B is relay used on ABY/AAN engines and that is in place now - same result.
>> 
>> Motronic EFI for ABY is very diffent connections than the CIS cars and 
>> there are 5 supplemental fuses in the harness.  The S2 wiring harness 
>> does make it possible to mostly plug into the older style fuse boxes 
>> whereas AAN harnesses need to be significantly "hacked".  There are 
>> still a lot of wiring integrations to be made if one wants to retain the factory
> wiring as best as possible - me that is.
>> 
>> I wired up according to the diagrams on S2 Forum 
>> http://s2central.net/main_frame.html
>> but there is probably something I am missing or not connecting.  For 
>> ex. With the ABY harness in place, I now have two wirings for 
>> after-run circuit.  A bunch of stuff like that and differences in the instrument
> cluster connections and HVAC connections.
>> 
>> I'm close and would be great to fire this engine up tonight!
>> 
>> Ben
>> 
>> -----Original Message-----
>> From: Huw Powell [mailto:audi at humanspeakers.com]
>> Sent: Friday, September 24, 2010 3:03 PM
>> To: Ben Swann
>> Cc: quattro at audifans.com; '200q20V mailing list'
>> Subject: Re: Fusebox internals - map/diagram
>> 
>> On my diagram the ECU power comes from B87F, output from the fuel pump 
>> relay - which is why that is usually labeled "Jetronic".  A G/Y wire.
>> 
>> But that has to come with a grain of salt, because these fuse boxes 
>> had the "spare" fuse on the side that was in this circuit, right?  And 
>> then of course the EFI might be quite different from the CIS variants...
>> 
>> On 9/24/2010 2:19 PM, Ben Swann wrote:
>>> Huw,
>>> 
>>> I did find a way to print out yours - It is definitely helpful.  
>>> There are variations between the boxes, but layout and terminals are 
>>> mostly the same.  Some wires have been added or re-purposed.
>>> 
>>> Looks like I may be missing the power supply lead in the ABY harness, 
>>> or have it confused with a different lead.  I should have it figured out today.
>>> 
>>> Hopefully the S2 will soon be on the road!
>>> 
>>> Ben
>>> 
>>> -----Original Message-----
>>> From: Huw Powell [mailto:audi at humanspeakers.com]
>>> Sent: Friday, September 24, 2010 12:50 PM
>>> To: Ben Swann
>>> Cc: quattro at audifans.com; '200q20V mailing list'
>>> Subject: Re: Fusebox internals - map/diagram
>>> 
>>> Obviously, one route would be to do what I did, and use the Bentley 
>>> as a source and rearrange everything.
>>> 
>>> Since I suspect they are very similar, you could work with a printout 
>>> of mine (it fits on 8.5 x 14 paper), and check it off against your 
>>> diagrams to see if there are any differences.
>>> 
>>> My diagram is probably the 85-87 type 85 fusebox, I don't know how 
>>> much they changed, I suspect not much.
>>> 
>>> On 9/24/2010 9:02 AM, Ben Swann wrote:
>>>> 
>>>> I am re-wiring my '90 CQ for installation of S2 ABY engine.
>>>> Presently everything is hooked up to proper terminals as best as I 
>>>> can tell, but don't seem to be getting power to the ECU.  Tracing 
>>>> reveals that for some reason major portions of the fusebox are not 
>>>> getting power.  The ignition switch and all electrical systems were 
>>>> working when I pulled the 7A engine
>>> about 2 years ago.  I['m not ruling out a bad wire or switch.
>>>> 
>>>> What would be helpful is a diagram or map of fusebox internals that 
>>>> show connections between relays and terminals.  The one on Huws site 
>>>> is helpful, but I'm wondering if there are any other versions that 
>>>> can be printed out or have view of connections pertaining to '90 
>>>> coupe quattro,  200 turbo quattro or even the S2 ABY in english of course.
>>>> 
>>>> Ben
>>>> _______________________________________________
>>>> quattro mailing list
>>>> http://www.audifans.com/mailman/listinfo/quattro
>>>> http://www.audifans.com/kb/List_information
>>>> 
>>> 
>>> --
>>> Huw Powell
>>> 
>>> http://www.humanspeakers.com/audi
>>> 
>>> http://www.humanthoughts.org/
>>> 
>>> 
>> 
>> --
>> Huw Powell
>> 
>> http://www.humanspeakers.com/audi
>> 
>> http://www.humanthoughts.org/
>> 
>> 
> 
> --
> Huw Powell
> 
> http://www.humanspeakers.com/audi
> 
> http://www.humanthoughts.org/
> 
> _______________________________________________
> quattro mailing list
> http://www.audifans.com/mailman/listinfo/quattro
> http://www.audifans.com/kb/List_information

More information about the 200q20v mailing list