VW / Audi / Seat / Skoda (VAG) Bosch M3.8.2 Engine ECU Repairs

Type: Bosch Engine Management
Fits: VAG – Audi / Seat / Skoda / Volkswagen (VW)
Fuel: Petrol
Ref: ECUT184195

Note: This ECU may also fit other models.

An A3, an A4, an A6, an A8, a Cabriolet and a Passat — the estate included — are all documented against the Bosch references listed on this page, on engines running from a 1.8 four-cylinder to a 2.8 V6 30-valve. Published listings and catalogue records date these units across 1996 to 1998.

The table below is not one car’s parts list. It covers a good part of one manufacturer’s petrol range for the second half of the 1990s, and what follows sets out which references the published parts records place against which of those cars.

The 1.8 references for the A4 and the Passat

Four references on this page are documented against the same two cars — the Audi A4 (8D2, B5) and the VW Passat, both with the 1.8. It is the largest group in the table, and it is the reason an A4 owner and a Passat owner can arrive at the same row.

• 0261204182 and 0261204183, against 8D0 907 557 S — an A4 or Passat 1.8 with engine code AFY, in records dated 1996.
• 0261204614, against 8D0 907 558 F — the A4 and Passat 1.8, in records dated 1996 and 1997; one parts record traces its unit to a VW Passat B5 Estate (3B5).
• 0261204774, against 8D0 907 558 B — the A4 and Passat 1.8 with engine code ADR.
• 0261204805, against 8D0 907 558 E — the A4 and Passat 1.8, filed under engine codes AEB and APU.

The Passat applications here are documented as plainly as the Audi ones, and a Passat unit comes in under the same service as the rest of the Volkswagens we rebuild engine ECUs for.

The 1.8 turbo references

Five references are documented against turbocharged 1.8s, and between them they cover the A4 and S4, the A6 and the Passat. The A6 is named in four of the five.

• 0261204184 and 0261204185, against 8D0 907 557 T — the A4, the A6 and the Passat 1.8T, in records dated 1997; one listing gives the output as 150 hp.
• 0261204252, against 4B0 907 557 — the Audi A6 1.8.
• 0261204256 — the Audi A6 1.8 turbo, in records dated 1997.
• 0261204806 — the Audi A6 (4B2, C5) 1.8 T, named as the primary application in one parts record.
• 0261206429 — the Audi A4 and S4 1.8T with engine code AJL.

The A4 and S4 reference is the only one in this group that does not name the A6.

The V6 references, 2.4 and 2.8

The V6 group reaches four model lines — the A4, the A6, the A8 and the Passat — across both 30-valve capacities.

• 0261204687, against 4D0 907 551 F — the Audi A4 and A6 2.8 quattro, in records dated 1997.
• 0261204690, against 4D0 907 551 R — the A4, the A6 and the VW Passat 2.8 V6 30V, in records dated 1998.
• 0261204686, against 4D0 907 551 M — the Audi A8 2.8, the only A8 application on the page.
• 0261204767, against 4B0 907 552 C — the Audi A4 (B5) and A6 2.4 V6 30V, with one listing giving 165 CV. A UK remanufacturer’s catalogue carries the same pairing of numbers.

One of these four is documented against the Passat as well as the Audis, which puts the 2.8 V6 30V on both marques.

The A3 and the Cabriolet

Two more model lines appear, each documented against references that turn up nowhere else in the table, and neither shares a reference with the cars above.

0261204126 and 0261204127 are documented against the Audi A3 (8L1) with the 1.8. A second A3 reference, 0261204254 against 06A 906 018 D, is filed to the A3 1.8 in records dated 1998.

0261204745, against 8G0 907 557 B, is the one that sits furthest from the rest: an Audi Cabriolet B3 (8G7) 1.8, rated in the record at 125 hp, with the unit itself taken off a 1996 car. It is the only Cabriolet application on this page.

If the car is an Audi and the reference on your unit is not one of the numbers above, the Audi engine ECU repair hub covers the other designations we take in.

Reading the same references from the car

A reader who has the car rather than the unit can come at the table from the other side. The A4 and the A6 have the widest coverage of the six: each is documented with the 1.8, the 1.8T, the 2.4 V6 30V and the 2.8 V6 30V. The Passat appears with the 1.8, the 1.8T and the 2.8 V6 30V, the estate included. The A3 accounts for three numbers, all of them 1.8. The A8 and the Cabriolet have one reference each, the 2.8 and the 1.8 respectively.

Six model lines and four engine sizes sit under one Bosch designation, so knowing that a unit is an M3.8.2 places it in the right family and does not take you much further. What makes it a specific job is the reference printed on the unit’s own label, taken together with the car it came out of: the model line, the capacity, and whether it is turbocharged. With both of those in front of us, the row that describes the unit is usually plain.

Component-level work on the board that arrives

Whichever of the references above is on the case, the repair itself is the same kind of work. The unit is logged in, inspected and electrically tested before anything is opened up, and the fault is then traced on the board rather than inferred from how the car had been behaving. Component-level work is carried out under a microscope with temperature-controlled rework equipment, and a unit is not finished until it has passed final testing.

All of that happens in-house, by our own engineers, in our own UK workshop; nothing is sent out. The work is a repair and nothing more: no tuning files, no software changes, no alteration to how the engine was set up to run. The repair carried out is covered by a 24-month warranty.

We work by post, across the whole of the UK. If you have a unit off one of these cars, ask us to take a look through the Repair Form, and give us the Bosch number from the label along with the model and engine — the unit is tested and diagnosed first, and you hear what we have found before any chargeable work begins. If the number on your label is not one of those above, it is still worth asking; the technical team confirms coverage against the unit itself rather than guessing from the model.

Common part numbers associated with this type of unit