Tool

Mercedes 1.3T & 2.0T (MHEV & PHEV) with Bosch MG1CS701 (MRG5) & MG1CP777 (MRG4) Now Unlocked!

Mercedes 1.3T & 2.0T (MHEV & PHEV) with Bosch MG1CS701 (MRG5) & MG1CP777 (MRG4) Now Unlocked!

New AT Protocol!

Dear Users,

The market for latest-generation everyday drivers is expanding! We are thrilled to announce that the state-of-the-art Bosch MG1CS701 (MRG5) and Bosch MG1CP777 (MRG4) ECUs are now officially supported on your AutoTuner Tool.

💡 Why these new ECUs from Mercedes? To fit highly demanding modern efficiency standards, Mercedes-Benz heavily updated its popular compact lineup (A-Class, B-Class, CLA, GLA, GLB). The well-known 1.3T and 2.0T powerplants transitioned into Mild-Hybrid (MHEV) and Plug-in Hybrid (PHEV) systems. This technological shift required the factory introduction of these all-new ECU platforms (MRG4 & MRG5), packed with sophisticated security layers.

With this release, you now hold the perfect tuning solution to optimize the performance and fuel efficiency of these high-volume vehicles!

🔒 Advanced Workflow (Mail-in ➡️ Bench):

Mail-in Unlock: The ECU must first be sent to our headquarters for a secure hardware unlock by our engineering team.

Bench: Once returned to your workshop, software restrictions are removed. You gain total Bench access to safely read and write your calibrations directly on your workbench—no ECU opening required.

Fleet Coverage Highlights (1.3T & 2.0T MHEV / PHEV Engines):

1.3T Range (Bosch MG1CS701 - MRG5): Mercedes A-Class, B-Class, CLA, GLA, GLB (180 MHEV, 200 MHEV & 250e PHEV configurations).

2.0T Range (Bosch MG1CP777 - MRG4): Mercedes A-Class, CLA, GLA, GLB (220 MHEV, 250 MHEV, and the performance-driven 35 AMG MHEV).

Specific to the USA:

✅ 2024+ CLA250 / CLA35 AMG
✅ 2024+ GLA250 / GLA35 AMG
✅ 2024+ GLB250 / GLB35 AMG


Update your software today and stay ahead of the game in modern electrified Mercedes tuning!

The AT Team

👉 Unlock for Mercedes MDG1/4/5

👉 Reusable ECU shipping case

Key Features

  • Type: Engine Control Unit (ECU) ⚙️
  • Mode: BENCH NR 🔌
  • MCU: TC387 🖥️
  • Read time: 2min ⏱️
  • Write time: 1min ⏱️
  • Checksums correction ✅
  • Backup creation 🔄
  • Mail-in unlock needed 📦

Compatibility List*

🚗 Mercedes Models: A (2018) / B (2019) / CLA (2019) / GLA (2020) / GLB (2019)
🔧 Mercedes Engines: 180 MHEV / 200 MHEV / 220 MHEV / 250 MHEV / 250e PHEV / 35 AMG MHEV

*The list may evolve over time.

Blog posts

View all
ToolVolkswagen LATAM Market support on the Tool (Marelli 9GV)

Volkswagen LATAM Market support on the Tool (Marelli 9GV)

New AT protocol! Dear Users, A high-volume protocol update has landed on your equipment! We are thrilled to announce official support for the Marelli 9GV ECU in Bench mode (Normal Read) on your Aut...

ToolMaserati MC20, GranCabrio, Grantourismo, Grecale, and MCPura ECU Now Unlocked!

Maserati MC20, GranCabrio, Grantourismo, Grecale, and MCPura ECU Now Unlocked!

Maserati 3.0T owners, now it’s your turn! It's time to show the world what this platform can really do. We can unlock your Bosch MG1CS039 ECU right here at our HQ in Auburn, Alabama. Once unlocked,...

ToolLate 90's BMW with Siemens MS42 ECUs now 100% OBD on the Tool!

Late 90's BMW with Siemens MS42 ECUs now 100% OBD on the Tool!

Siemens MS42 OBD Protocol Release! Dear Users, Take full control over legendary late-90s Bavarian straight-six powerplants! We are thrilled to announce official support for the Siemens MS42 ECU via...

Want to know more?

Discover our story

About AutoTuner