MAC-14 Diagnostics

suffolkd at suffolkd at
Wed Sep 26 19:21:41 PDT 2007


 Do you need the 2x2 ugly connector?

or are you going to install a check engine bulb in the dash and try to blink out code with a fuse?
-Scott by BOSTON


-----Original Message-----
From: Ben Swann <benswann at>
To: suffolkd at; 200q20v at
Cc: quattro at; 'Ben Swann' <benswann at>
Sent: Wed, 26 Sep 2007 10:14 pm
Subject: RE: MAC-14 Diagnostics

I think we are confusing things
here.  I am simply trying to blink out codes for now – should at
least be able to do this.  In fact I know it can be done and have done it
before, just not on a transplanted MC-2/MAC-14 setup.  And of course this
is the MC-2 10V CIS hybrid not the 3B 20V efi , but there are many who
subscribe to this list because the ‘89 and ‘90 200Q are more
similar to the ’91 20V despite that the engine is Motronic EFI instead of
the hybrid variant that was MAC-14.  Furthermore the diagnostics
techniques spelled out in the Bently for the MC-2 are actually quite similar to
the 3B probably closer “procedure-wise” than the MC-1.  But
still the option to blink out codes is there – just sometimes need to
install a check engine light, according to procedure.  I have the feeling
some other things have been left out and because the procedure calls for using
specialized VAG equipment, one needs to guess at what these things actually
are.  I also think there may be errors or omissions in the diagram.


With that, it would also be nice to use
VAG-COM as the com interface is supposedly there.  So you are saying that
you have not been able to use VAG-COM on an MC-2/MAC-14?  I haven’t
either, but Bentley and SJM suggest it can be done.


At the very least, I should be able to
blink codes like on the MC-1.




From: suffolkd at
[mailto:suffolkd at] 

Sent: Wednesday, September 26,
2007 8:17 PM

To: 200q20v at;
benswann at

Subject: Re: MAC-14 Diagnostics


The earliest EU I could read was a
200 20V 3B.  AFAIK the MAc -14 is for a MC-2

BAck when Vag Com came out i asked if it could read a 1990 200 10V (Mac - 14)
we never tested it.

VAg-Com site listed the 3B as the earliest to "work" a few years
ago.  I don't know if that has changed.....


other searchs just brings up some of your posts :-)  




**Ben*** Right - it  seems like I’m
the one who ventures into these territories first.  I have a complete
pinout spreadsheet for wiring this beast and how to hook it up with
Megasquirt.  I don’t like putting things out there until everything
is working right.  I figured someone has likely done an MC-2/MAC-14
transplant into a 4kq or CGT along with associated wiring. – then they
would likely have had to go through this.  ***Ben***


-Scott by BOSTON

From: "Ben Swann" <>

I’m trying to run codes on my MAC-14 ECU which is currently setup to do only  

Ignition for my Megasquirt setup.  The wiring harness has been completely transplanted,  

and I installed connectors for the ?dirty? OBD to connect to VAG-COM.  VAG-COM is not picking

up on it.

Has anyone retrieved codes via VAG-COM for the MAC-14?

I will try connecting to flash the codes, but would be nice to use the OBD features.

Anyone had much success flashing the codes using fuse and CEL?  I don’t have identical wiring with Fuel Pump Relay, but have wired according to Bentley.  Wondering if I am missing anything for this.



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