Hoe koop je een gebruikte ECU 04E907309FT voor VW, Audi, SEAT & Skoda

What Is the 04E907309FT ECU and Which Cars Use It?

The Bosch ECU 04E907309FT (also carrying the Bosch internal number 0261S105MZ) is an engine control unit designed for Volkswagen Group vehicles fitted with the EA211 petrol engine family — primarily the 1.4 TSI, 1.0 TSI, and 1.0 MPI variants. It manages fuel injection timing, ignition, idle control, and emissions across a broad platform.

Confirmed fitments include:

• VW Golf VII 1.4 TSI
• VW Polo 1.4 TSI and Polo AW (2017–)
• Audi A3 8V 1.4 TFSI
• Skoda Octavia III 1.4 TSI
• ŠKODA Fabia NJ (2015–)
• SEAT Leon III 1.4 TSI
• SEAT Ibiza KJ (2017–)
• VW up! / SEAT Mii / ŠKODA Citigo (possible — always verify before purchase)

Because the EA211 platform is shared across so many models, a single ECU part number can serve a surprisingly wide range of vehicles.

You can view the used unit currently in stock at AutoParts EU here, or browse the full electronics category for other control modules.

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How to Identify It: OEM Number and Label Markings

Look for two numbers on the ECU casing:

1. VAG OEM number: 04E907309FT — printed on the white or silver label affixed to the unit.
2. Bosch part number: 0261S105MZ — this is the manufacturer's own reference, also on the label.

Both numbers should be present and legible. If either is missing or partially obscured, ask the seller for photos of the label before purchase. The connector pinout and housing shape should also match your existing unit visually.

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Cross-Reference Numbers

When searching alternative suppliers or verifying compatibility, these cross-reference numbers are associated with the same unit:

| Reference Type | Number | |---|---| | VAG OEM | 04E907309FT | | Bosch (manufacturer) | 0261S105MZ | | Cross-ref 1 | 266-08 | | Cross-ref 2 | 1035100138 |

Always confirm the full OEM number matches your vehicle's existing ECU — even minor suffix differences (e.g. FT vs. FL) can indicate a different calibration.

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What to Check Before Buying a Used ECU

Buying a used ECU is cost-effective, but a few checks are essential:

• Match the exact OEM suffix. 04E907309FT is not interchangeable with other suffixes without professional reprogramming.
• Condition of connectors. Bent or corroded pins cause intermittent faults and are expensive to repair.
• Water damage. Inspect the housing for any signs of moisture ingress or corrosion on the circuit board if possible.
• Coding and adaptation. Used ECUs almost always require coding/adaptation to your specific vehicle using VCDS, ODIS, or a dealer tool. Factor this into your total cost.
• Mileage and origin. Ask where the unit was removed from — ideally a low-mileage donor vehicle.
• No tamper seals broken for emissions or tuning — this can create MOT or warranty complications.

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FAQ

Will this ECU work immediately after fitting?

Not always. Used VAG ECUs typically need to be coded to the vehicle using VW/Skoda/Seat/Audi diagnostic software. A plug-and-play installation without coding will usually result in fault codes or the engine not starting.

Can one 04E907309FT unit fit both 1.4 TSI and 1.0 TSI engines?

The EA211 platform shares hardware across engine sizes, but the software calibration is engine-specific. The ECU must be reprogrammed for the target engine if it was removed from a different variant — confirm with a VAG specialist before purchasing.

How do I know if my ECU is faulty and not another component?

Common symptoms — no-start, misfires, loss of power, or multiple unrelated fault codes — can indicate ECU failure, but always rule out wiring faults, sensors, and connector issues first. A proper diagnostic scan pointing to internal ECU errors is the strongest indicator.