JOHN DEERE · L21 ECU

JOHN DEERE S660 L21 tuning files

Tuning file coverage for the JOHN DEERE S660 running the L21 ECU. The matched variants sit between 325 and 365 HP from the factory. Stage 1 and Stage 2 are the safe starting points for this platform. Each file is tied to the precise software on your car and checked before it goes out.

Upload your file →All S660 coverage Custom ECU tuning file service

Available solutions

Solutions that apply to the L21 on this vehicle platform. The exact set depends on the specific engine and software version.

Stage 1 Stage 2

Engine variants & ECU software

4 distinct variants for the JOHN DEERE S660 on the L21 ECU. Reference the engine and controller software when you upload.

Variant 1

ECU

Catalog engine: 9000 365HP
Controller brand: PHOENIX
ECU: L21
Stock power: 365 HP

Variant 2

ECU

Catalog engine: 9000 365HP
Engine code: 6090HCQ04
Controller brand: PHOENIX
ECU: L21
Stock power: 365 HP
ECU SW: SW63227A
ECU HW: RE571640

Variant 3

ECU

Catalog engine: 9000 325HP
Controller brand: PHOENIX
ECU: L21
Stock power: 325 HP

Variant 4

ECU

Catalog engine: 9000 325HP
Engine code: 6068HL490
Controller brand: PHOENIX
ECU: L21
Stock power: 325 HP
ECU HW: RE577140

Related vehicles

Other vehicles built on the L21 controller or the same engine — handy when a platform spans several models and makes.

Questions, answered.

Which tuning solutions are available for the JOHN DEERE S660 on the L21?

Stage 1, Stage 2. The exact set depends on the specific engine and software version.

Do you cover the L21 ECU software on this model?

Yes — the JOHN DEERE S660 on the L21 ECU is part of the catalog. Upload your original file and it is matched to the right calibration before any work is done.

How is the file delivered?

Through the TuningBay workflow with operator validation and one safe, sensible result per job. Files we deliver, we stand behind.