VW / Audi / Seat / Skoda (VAG) Bosch MP9.0 Engine ECU Repairs

Type: Bosch Engine Management
Fits: VAG – Audi / Seat / Skoda / Volkswagen (VW)
Fuel: Petrol
Ref: ECUT204195

Note: This ECU may also fit other models.

Bosch MP9.0 engine management is recorded under two badges: small Volkswagen petrol cars and small Seats. Knowing which of the two you drive narrows things down less than you might expect, because both marques have MP9.0 units recorded on 1.0 and 1.4 engines. The reference printed on the case is what does the narrowing.

What follows sets each well-documented reference against its car, Volkswagen first and then Seat, before turning to how the label should be read and what happens to the unit in our workshop.

Which cars the Bosch MP9.0 is recorded against

On the Volkswagen side, the references on this page are recorded against the Polo with the 1.0 and 1.4 engines and the Golf 1.4. On the Seat side, they are recorded against the Ibiza 1.4, the Cordoba 1.4 and the Arosa 1.0.

Each of those pairings is one that at least two independent sources agree on. Independent sellers also list most of these units under the MP9.0 name, so the designation on this page is the one you are likely to meet when searching elsewhere.

The Fits: line at the top is the group-wide line we use across our VAG references. Every car named on this page is a Volkswagen or a Seat.

Volkswagen Polo and Golf MP9.0 references

The Polo accounts for most of the Volkswagen references here, and it divides by engine size. For the Polo 1.0, the unit is Bosch 0 261 203 931/932, which sellers print as a single pair, with VAG number 030 906 027 E. Listings for it also give the engine code AER.

The Polo 1.4 has two pairs of its own: Bosch 0 261 203 914/915, and Bosch 0 261 204 616/617. Listings for the second pair print VAG number 030 906 027 AA beside it.

A single reference completes the Volkswagen side. Bosch 0 261 203 613, with VAG number 030 906 027 M, is recorded against the Golf 1.4.

If the case from your Volkswagen carries none of the numbers in our MP9.0 table, look for its family in our Volkswagen engine ECU collection.

Seat Ibiza, Cordoba and Arosa MP9.0 references

The Seat references divide by engine size too. The Arosa 1.0 is recorded with Bosch 0 261 203 930 and VAG number 030 906 027 AK, and listings for that unit also give the AER engine code.

The Ibiza 1.4 and Cordoba 1.4 share one pair, Bosch 0 261 204 054/055, printed with VAG number 6K0 906 027 A. The same pair is also listed for the Caddy.

Two further references are each recorded against a single Seat model. Bosch 0 261 204 844 is recorded against the Ibiza 1.4, with VAG number 6K0 906 027 J printed alongside it, and Bosch 0 261 204 593 is recorded against the Cordoba 1.4.

Among the references discussed here, an Ibiza 1.4 therefore has two candidates, the 054/055 pair and 0 261 204 844, and a Cordoba 1.4 has two, the 054/055 pair and 0 261 204 593. Seat engine ECUs from other Bosch families are covered in the full Seat engine ECU line-up.

The 1.0 and 1.4 engines appear under both badges

Putting the two marques side by side shows how little the marque settles on its own. The AER engine code turns up on both: in the Polo 1.0 with Bosch 0 261 203 931/932 and 030 906 027 E, and in the Arosa 1.0 with Bosch 0 261 203 930 and 030 906 027 AK.

The engine code is shared; the recorded references are not. Each car appears with its own Bosch number and its own VAG number, so knowing you have an AER engine still leaves the choice to the label.

The 1.4 is spread wider still. References on this page are recorded against the Polo 1.4, the Golf 1.4, the Ibiza 1.4 and the Cordoba 1.4, and the only one shared between two of those cars is the 054/055 pair, which is recorded for both Seats.

Under either marque, a 1.4 still leaves more than one MP9.0 reference in play, and the label on the case decides which.

Reading an MP9.0 label printed as a pair

Sellers routinely print these Bosch references in pairs for a single unit: 054/055, 914/915, 931/932 and 616/617 all appear that way. If the number on your case is 0 261 204 055 and a listing leads with 054, that is the same pairing seen from its other half, not a mismatch.

Our table gives each half its own row. That is why 0 261 204 054 and 0 261 204 055 appear separately there, both against 6K0 906 027 A.

Next to the ten-digit Bosch reference, the label carries the VAG part number. Note that as well, exactly as printed.

Our table holds nineteen MP9.0 references, and not every one is discussed above. Whichever one your unit carries, our engineers confirm coverage against what the label says rather than against a description of the car.

If the unit came from another make altogether, go back to the starting point for all engine ECU repairs.

How we repair a Bosch MP9.0 in our UK workshop

The car stays where it is; the MP9.0 comes to our workshop by post, from anywhere in the UK.

On arrival each unit is logged and looked over, then tested electrically, and only after that does diagnosis turn to the fault you reported. Board-level work is done under a microscope, and every joint that is reworked is made with temperature-controlled equipment.

The fault is traced to the specific component that has failed, and that component is repaired or replaced on the board. The work is done in-house by our own engineers, on our own equipment, with nothing sent out to a third party.

When diagnosis is complete, we contact you with what we found and the repair it calls for. Repair work starts only once you have authorised it.

Every repaired unit has to pass a final test before it leaves us, and the repair is covered by a 24-month warranty.

With the Bosch number, the VAG number and the car’s model and engine to hand, open a repair job for your MP9.0 through our Repair Form.

The nineteen MP9.0 references we repair are listed below.

Common part numbers associated with this type of unit