VW / Audi / Seat / Skoda (VAG) Siemens Digifant Engine ECU Repairs

Type: Digifant Engine Management
Fits: VAG – Audi / Seat / Skoda / Volkswagen (VW)
Fuel: Petrol
Ref: ECUT213195

Note: This ECU may also fit other models.

The engine ECUs on this page come out of three quite different vehicles: the Volkswagen T4 Transporter, the Mk2 and Mk3 Volkswagen Golf, and the Audi 80, 100 and Coupe. A van kept working, a classic hatchback kept original and an older Audi kept on the road all need the same thing when the Digifant unit is under suspicion: the original engine ECU tested and, if it is at fault, repaired. This page is arranged around those three owners, so you can go straight to the vehicle you have. Three outliers — a T3 Transporter unit, a G60 unit and a Beetle unit — follow at the end.

Why the VW part number matters more than the Siemens name

Digifant is Volkswagen’s own engine-management system, and the control units that run it were not all built by one company. Siemens built Digifant units, and so did Bosch, TEMIC and Triumph-Adler. The same Volkswagen part number can even turn up on units from more than one of those makers.

That is why this page, despite the Siemens name in its title, does not ask you to work out who made your unit. The number that identifies it is the Volkswagen one printed on the label, in the form 023 906 022 H or 037 906 024 AB — a three-digit prefix, 906, a three-digit group and usually one or two letters. That is the number the table is built around, and the one we match your unit against when it arrives.

The first three digits also make a quick cross-check, because across these references they broadly follow the vehicle: 023 and 044 on T4 vans, 037 mostly on Golfs, 039 on Audis. It is a pattern in this list, not a rule — 037 906 022 EE, for one, is an Audi unit — so let the whole number, letters included, have the final say.

For T4 Transporter owners: the 2.5 and 2.0 petrol vans

The T4 accounts for more of the documented references on this page than any other vehicle. They divide by engine into three groups, and the number on the label tells you which one you are holding.

The earlier 2.5-litre engine, code AAF, runs on references beginning 023 906 022. The E, F, H and J versions are all recorded against the T4 2.5 with the AAF engine, while 023 906 022 M is recorded against the T4 with no engine the records agree on. The H is also listed against the Eurovan, the name the T4 carried in the US.

The later 2.5, engine code ACU, sits on references beginning 023 906 024. The P, Q and R versions are recorded against the T4 2.5 ACU, and the Q is listed against the Caravelle as well. 023 906 024 F is a T4 2.5 unit, but the records do not settle its engine code, so go by the full number rather than assuming ACU.

The 2.0-litre T4, engine code AAC, has its own prefix, 044. References 044 906 022 E, H, M and R and 044 906 024 E are all recorded against the T4 2.0 AAC. Two more, 044 906 022 L and the plain 044 906 024, are recorded against the T4 with no engine code the records settle.

For a van owner, the engine size narrows things to one prefix on this page — 023 for a 2.5, 044 for a 2.0 — and the letters on the label narrow it to one unit. An AAF unit and an ACU unit share the 023 906 start and the same 2.5-litre T4, so the digits after it are what separate them.

For Mk2 and Mk3 Golf owners

On the Mk2 Golf GTI 8V, two references are documented. 037 906 022 BC is recorded against the Mk2 GTI 1.8 8V, and it is listed for the Jetta too. 037 906 022 E is recorded against the Mk2 GTI 8V with the PB engine, and is described as a Digifant II unit.

The Mk3 Golf is where the numbers need most care. Both the 16-valve 2.0 and the 8-valve 2.0 use references beginning 037 906 024, so the prefix alone cannot tell them apart; the letters after it do.

The 16-valve engine is code ABF. References 037 906 024 AB and AE are recorded against the Mk3 Golf GTI 2.0 16V with that engine, and 037 906 024 G is recorded against the ABF engine without the records settling a model. 037 906 024 BE is the ABF unit that crosses marques: it is recorded against the Golf GTI and the Seat Ibiza, and is described as Digifant 3.2. Ibiza owners holding a different reference should look at Seat engine ECU repair.

The 8-valve 2.0 is code 2E. 037 906 024 AG and B are both recorded against the Mk3 Golf 2.0 8V with the 2E engine, and the AG is listed for the Passat as well. Two further references, 037 906 024 D and S, are recorded on Golfs without an engine code the records settle — the D as a Golf 2.0 GTI — so for those two we go by the number alone.

If a classic Golf has had an engine swap at some point, the unit fitted may not be the one the car left the factory with — another reason to read the label on the unit itself rather than work from the car’s original specification. For a Volkswagen outside the Digifant units on this page, see everything else we repair from Volkswagen.

For Audi 80, 100 and Coupe owners

The Audi references are fewer, and three of them tell the same story. 037 906 022 EE, 039 906 022 and 039 906 024 A are each recorded against the Audi 80 B4 and the Audi Coupe with the 2.0 petrol engine.

039 906 024 D reaches furthest. It is recorded against the Audi 80 B4, the Audi 100, the A6 and the Coupe, and against the 2.0 ABK engine. The plain 039 906 024, with no letter after it, is recorded against the Audi 100.

For an Audi owner, the model name alone does not pick the unit: an 80 B4 2.0 could carry any of four references on this page, and an Audi 100 either of two. The number on the label is what separates them. An Audi whose reference is not listed here belongs under Audi engine ECU repairs.

Three outliers: a T3, a G60 and a Mexican Beetle

025 906 022 is recorded against the T3 Transporter, the van that came before the T4. It is the only reference on this page for that model.

037 906 022 EH is recorded against the G60, the supercharged 1.8. The records do not settle which model it came from, so we describe it by engine alone.

043 906 022 B is recorded against the Volkswagen Beetle — the Type 1 — in the Mexican-built form sold as the Sedan.

The table carries further references that are not described above. Where the vehicle behind a number cannot be stated with confidence, this page leaves it unnamed rather than guess; the number itself is enough for us to work from.

Having a Digifant engine ECU repaired by post

We repair engine ECUs, and only engine ECUs, in our own UK workshop. A Digifant unit that arrives here is logged, inspected and electrically tested before any fault-specific work begins, and the repair is made at component level on the board you sent rather than by swapping in another unit. Units for other makes start from the engine ECU repairs contents page.

For a T4, a classic Golf or an older Audi, that means the vehicle keeps its own engine ECU rather than taking on a used replacement whose history nobody can vouch for.

Once the unit has been tested, we contact you with what we found and what the repair involves, and no chargeable work starts until you have authorised it. The repair is then covered by a 24-month warranty.

To start, fill in a Repair Form for the van, Golf or Audi with the full Volkswagen number from the label, the vehicle and its engine code if you know it. The service is mail-in only and open to owners and garages anywhere in the UK.

The table below lists the part numbers this page covers. Check your label against it before you fill in the form.

Common part numbers associated with this type of unit