VW / Audi / Seat / Skoda (VAG) Siemens Simos 2 Engine ECU Repairs

Type: Siemens
Fits: VAG – Audi / Seat / Skoda / Volkswagen (VW)
Fuel: Petrol
Ref: ECUT216195

Note: This ECU may also fit other models.

Several of the Simos 2 references on this page are recorded under more than one badge. The same part number turns up in a Golf 4 and a Bora, in a Seat Leon and a Toledo, in a Passat and an Audi A4, and in an Ibiza alongside a Toledo and a Cordoba. Others stay with a single car.

Simos 2 belongs to Simos, a family of Siemens engine ECUs. Every reference described below is recorded in a 1.6 petrol Volkswagen, Audi or Seat, except for two from the Skoda Felicia 1.3. We repair Simos 2 units at component level in our own UK workshop. The page is arranged around those shared cars, pair by pair, showing where a number crosses from one badge to the next and where it stops, because that is where matching a unit to a car is easiest to get wrong.

Golf 4 and Bora: two references shared, three Golf-only

The Golf and Bora references in these records all sit on the 06A 906 019 base, and all are 1.6 petrol. Two of them are documented in both the Golf 4 and the Bora.

06A 906 019 AK has the fullest record of the five. It is documented in the Golf 4 1.6 and in the Bora, and against the 8-valve AKL engine. 06A 906 019 BQ is recorded in the same two cars, again as a 1.6.

The other three stay with the Golf. The unsuffixed 06A 906 019 is documented in the Golf 4 1.6, 06A 906 019 BF in the Golf 4 1.6 and 06A 906 019 CA in the Golf 1.6. We have no corroborated Bora record for any of them.

Of the references described here, then, a Bora points to two and a Golf to five, and in both cases the letter after 06A 906 019, or its absence, is what separates them. If the number on a Golf or Bora unit starts differently, it may belong to another engine ECU family; start from Volkswagen cars with a different engine ECU.

Audi A3 and Seat Leon or Toledo: one base, separate suffixes

The 06A 906 019 base is not only a Volkswagen number. Four more of its suffixes are recorded in the Audi A3 1.6, and one in the Seat Leon and Toledo 1.6.

On the A3, the records name engine codes for two of the four. 06A 906 019 BS is documented against both the AKL and the AEH, and 06A 906 019 D against the AEH. For 06A 906 019 AM and 06A 906 019 E the records give the A3 1.6 and no engine code we can stand behind, so we leave it open rather than guess.

06A 906 019 BR is the Seat reference on this base, and it spans two Seat bodies. Three separate sources record it in the Leon 1.6, and three in the Toledo 1.6.

What the records do not show is a suffix shared across marques on this base. Among the references described here, no 06A 906 019 suffix is recorded under more than one marque. The base runs through all three makes; the individual suffixes, on this evidence, keep to their own.

Passat and A4 1.6: seven 3B0 907 557 references, one crossing

The 3B0 907 557 base belongs to a different pairing: the Volkswagen Passat 1.6 and the Audi A4 1.6. Where the records name an engine against it, the code is AHL, and several suffixes are placed in the B5 generation of each car.

For the Passat, the unsuffixed 3B0 907 557 is recorded in the Passat 1.6 with the AHL, and 3B0 907 557 C in the B5 Passat 1.6 AHL.

For the A4, four references are recorded in the A4 1.6: A, B, E and N. B and E are each documented against the AHL in the B5 A4. For A and N the records give the car and the engine size, and we do not add to that.

3B0 907 557 P is the crossing point. It is documented in both the Passat and the A4, as a 1.6 with the AHL.

Put together, an A4 1.6 owner is looking at five references on this base and a Passat 1.6 owner at three, with P the only one common to both. If an A3 or A4 label matches nothing on this page, look at A3s and A4s with another unit fitted.

Ibiza, Toledo, Cordoba and the Felicia 1.3

6K0 906 019 is recorded in the Seat Ibiza 1.6, and in the Toledo and the Cordoba as well.

The Toledo is the one car on this page recorded under two different bases: 6K0 906 019 here, and 06A 906 019 BR in the Leon section above. The records we hold do not say which Toledo carries which, so the model name alone will not tell you which of the two you have. The label will: 6K0 at the start of one, 06A at the start of the other. For a Seat label that matches neither, see where we list Seat engine ECUs.

The Skoda Felicia is the outlier. Its two references, 047 906 030 C and 047 906 030 N, are the only 1.3 units described on this page and the only Skoda ones, and both are recorded in the Felicia 1.3. In the records the car does not separate them; the final letter does. A Skoda owner with any other model should look at Skodas beyond the Felicia.

Why a shared reference is a record, not a spare

When a reference crosses from one car to another, it tells you something narrow: independent sellers and catalogues have documented that part number in both cars. It does not tell you that a unit taken from one will run the other, and we would not advise fitting one on that basis.

The same caution holds inside a single model. Golf 4 1.6s appear against several 06A 906 019 suffixes and A4 1.6s against several 3B0 907 557 suffixes, so matching the model and the engine size does not settle the unit.

That is why we identify each Simos 2 from the full part number on its label, read alongside the car it came from. When the two agree with the records, the identification is sound; when they do not, it is worth a second look at the label before anything goes in the post. It is also why we repair the unit you already have, which then goes back into the car it came out of.

Sending a Simos 2 to our UK workshop

We repair engine ECUs and nothing else, and every Simos 2 is handled in-house by our own engineers. Each unit is logged and inspected on arrival, then tested electrically before fault-specific diagnosis starts.

The repair itself is made at component level, on the part that has failed, using a microscope and temperature-controlled rework equipment. A unit is not finished until it passes final testing.

Once testing is complete we tell you what we found and quote for the repair, and we do nothing chargeable until you have agreed to it. Every repair carries a 24-month warranty.

The service runs by post, for owners and garages anywhere in the UK. When you are ready, name both the car and the reference on the Repair Form: the model and engine size, and the full number, including any letter after it. For a car from another maker entirely, the umbrella page for all our engine ECU repairs is the place to start.

Every reference listed for this page is in the table below, including several not described above. If yours is one of those, quote it on the form and we will confirm the match before you send anything.

Common part numbers associated with this type of unit