MAC-14 Diagnostics

Ben Swann benswann at
Wed Sep 26 19:14:55 PDT 2007

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
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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