MED17.5.20, 5.21 and 5.25 original and immo off files for VW 1.2/1.4 TSI (Golf VII, Polo, A3)

Golf VII 1.4 TSI, 04E906016 on the label, software 6391 in the tool, and the owner wants stage 1 because a mate’s car went well. Or a Polo 6C 1.2 TSI, 04E906027LJ, sold as a non-runner after an ECU was swapped without adaptation. Both are Bosch MED17.5 family, but the twincharger Golf VI next to them with 03C997022 is a different unit again. Three MED17.5 variants, three engine families, and the differences decide what’s safe to do.

Which is which

• MED17.5.20: EA111 1.4 TSI twincharger (CAVD, CTHD, CAVE) with 03C997022 numbers. Golf VI, Jetta VI, Scirocco, Polo GTI 6R, Ibiza Cupra, Fabia RS. Supercharger plus turbo, 140 to 180 hp.
• MED17.5.21: EA211 1.4 TSI (CHPA, CZCA, CZDA, CXSA) with 04E906016 and 04E997016 numbers. Golf VII, A3 8V, Octavia III, Leon 5F, Polo 6C 1.4 TSI, 122 to 150 hp, including the cylinder-deactivation ACT versions.
• MED17.5.25: EA211 1.2 TSI (CJZA, CJZB, CYVB) and some 1.4 TSI variants with 04E906027 and 04E997027 numbers. Polo 6C, Fabia III, Rapid, Golf VII 1.2, Leon 1.2, Ibiza 6P, 85 to 110 hp.

Sample numbers from our catalogue:

• VW GOLF MED17.5.20 03C997022 8648 1037515346
• VW JETTA MED17.5.20 03C997022B 6534 1037506811
• AUDI ALL MED17.5.21 04E906016 7700 1037543627
• AUDI ALL MED17.5.21 04E997016 0292 1037543923
• AUDI ALL MED17.5.21 04E997016B 0418 1037545243
• SEAT LEON MED17.5.25 04E997027A 9007 1037555144
• SKODA FABIA MED17.5.25 04E906027LJ 3996 10SW014667
• VW GOLF MED17.5.25 04E906027LD 5062 10SW023566

Note the 04E906016 on its own with 5543, 6391 and 7700 as three separate versions. Same part, three files. The version is on the label sometimes and in the tool always.

Stage 1 limits, honestly

1.4 TSI twincharger (5.20)

The 160 hp CAVD goes to about 190 to 200 with a stage 1, and the engine is known for piston and timing-chain trouble at stock power on some batches. Check for chain rattle at cold start, check oil consumption, and don’t push torque past 300 Nm on a DQ200 car. If it already burns oil, tune nothing.

1.4 TSI EA211 (5.21)

The 122/125 hp CHPA and CZCA take 150 to 160 hp comfortably; the 140/150 hp ACT engine lands at 170 to 180. The turbo is small and the gains are in the midrange. The seven-speed DQ200 with its dry clutches is the limit again, around 250 to 270 Nm in practice.

1.2 TSI (5.25)

90 hp to about 115 to 120, 110 hp to about 130. Modest, drivable, and the engine copes. Anything sold as a 150 hp stage 1 for a 1.2 is either marketing or a turbo swap.

Immo off and adaptation

EA211 cars are MQB, Immo 5. A replacement ECU needs online adaptation through ODIS with a dealer login, or an offline immo tool like VCP or AVDI on a virgin unit. Immo off is the alternative: the ECU starts the car without the cluster handshake. On the 5.20 (Golf VI, PQ platform) it’s Immo 4, and VCDS with a login can adapt; immo off is still useful when the cluster is the dead part. In every case we need the EEPROM and flash from the ECU being fitted, read on the bench.

Reading

MED17.5.20 reads and writes over OBD with KESS V2, KESS3 or Autotuner on most versions; some late software needs bench. MED17.5.21 and 5.25 on 2013 to 2016 software still read OBD with KESS3, Autotuner or Flex, but many were locked by later dealer updates, and then it’s bench (Flex, KT200, FoxFlash, New Trasdata) with the ECU out. TPROT is handled by the tool. Boot mode is the last resort for a bricked unit, and the recovery guide walks through it.

Originals by version are on the MED17.5.20, MED17.5.21 and MED17.5.25 pages, and the immo off versions sit in their own category. Send the read with a label photo through the request form if you don’t see your software number listed.