All of the 2.1 Digifant can use the same replacement ECUs. The 86/87
initially had different ECUs ending in 022. The later 022D version has
OBD Diagnostic support built in to comply with then impending Calif OBD
requirements. The 022D became the standard part for all replacements
sold through the dealer.

The FI wiring harness to use the OBD has a few extra pins in it at the
ECU connector. The ECU at least partially supports it and the FI harness
supports it but VW never fully implemented it in the Vanagon and it is
not documented. The Pin 23 wire is part of the intended OBD feature.

There are later versions of the 022D ECU that don't have a VW part
number and thus don't say 022 or 022D on them. The 022D is a Bosch
product and at some point Bosch began selling them through non-VW parts
channels without the VW number on them, just a Bosch number that does
not include 022D.

To repeat, any of the 4 different looking 2.1 Digifant ECUs should run
in any 2.1.

It is hard to say exactly what FI harness configuration will be in any
given Vanagon since the 2.1 harness came in various versions that did
not change on an exact model year in spite of the wiring diagram labels.
Also an early harness could have later been replaced by a newer version
as part of a repair or any year harness could be run in any year 2.1 van
if someone simply swapped engines along with harness or swapped the
harness separately.

Mark

Scott Daniel - Turbovans (by way of Rob <becida@comcast.net>) wrote:
> HI all..
> what year vanagon with digifant 2.1 engine and fuel injection system
> uses the 'Suffix D' ECU ?
>
> can a non suffix D ecu and a D suffix ecu be swapped back and forth ?
>
> on an 89 Vanagon with a 5 pin main/ecu relay ..
> what is the purpose of the BK/W wire ( see page 97.124 and 123 -
> Bentley ) from pin 4/86 on the relay to pin 23 of the ECU ?
>
> does an 87 Vanagon have a pin 23 on the ecu ? ...
>
> Does a 5 pin main/ecu relay and a Suffix D ecu ...do those two go
> together ? ( especially want to know this one )
>
> what feature does a Suffix D ecu have that the non-suffix D one doesn't ?
>
> thanks !
> scott
>