If you own a Smart Roadster 452, you already know the Softouch gearbox is one of the most divisive things about the car. When it is working well, it is tolerable. When it is sluggish and hesitant, it is genuinely exhausting in traffic. What many owners do not realise is that the ECU firmware version running on their Bosch MEG 1.1 has a direct and measurable effect on how fast and how cleanly those gear changes happen. Smart Roadster firmware 371568 — the full identifier being 1037371568 — is the final and best version released for this ECU, and upgrading to it is one of the most impactful software changes you can make to any Roadster. This article explains exactly what it changes, which cars have it already, which do not, and how to get it flashed correctly.
What Is Firmware 371568 and Why Does It Exist?
The Bosch MEG 1.1 ECU in the Smart Roadster is responsible for far more than fuel and ignition. It also manages the Softouch automated manual gearbox, controlling the timing and pressure of each gear engagement via the gear motor and actuator assembly. Smart’s engineers released several firmware revisions across the production run from 2003 to 2006, each refining how the ECU communicated with the drivetrain.
Firmware 1037371568 — commonly shortened to 371568 — was the last and most refined of these updates. It was not widely distributed to all cars during the production run, meaning a significant number of Roadsters left the factory or were serviced on older firmware versions. The difference between an early firmware and 371568 is not trivial. Smart’s calibration team used real-world feedback to tighten the gear engagement windows, reduce the hesitation period between clutch release and next-gear engagement, and smooth out the torque interruption that makes older firmware feel so clunky during spirited driving.
To understand where this firmware sits in the broader hierarchy of ECU software on these cars, the complete guide to Smart Roadster ECU firmware versions is essential reading before you decide whether your car needs updating.
What Exactly Does 371568 Change for Gear Changes?
The headline benefit is shift speed. On earlier firmware, the ECU imposes a longer wait between the clutch disengaging and the new gear being selected, a legacy of conservative calibration from early in the production cycle. Firmware 371568 tightens this window significantly, which translates into a noticeably crisper feel during upshifts and a reduction in the characteristic lurch that catches passengers off guard.
There are several specific areas where the calibration differs:
- Clutch engagement ramp rate: 371568 uses a steeper ramp, meaning the clutch bites more decisively rather than slipping in gradually. This reduces the rubbery, indeterminate feel of older maps.
- Gear motor dwell time: The time the ECU waits for the gear motor to confirm selection before releasing the clutch is shortened on 371568, cutting the dead time in each shift.
- Throttle blip on downshift: The automatic throttle blip for downshifts is better timed on 371568, making heel-and-toe-style manual downshifts feel considerably more natural.
- Cold-start shift behaviour: Early firmware was notably more sluggish when the gearbox oil was cold. 371568 reduces this effect, though a proper gearbox oil service with the correct specification fluid is still essential for best results.
The combined effect is a gearbox that still cannot compete with a modern dual-clutch transmission, but which feels markedly more responsive and less fatiguing on the road.
Which Cars Already Have 371568?
This is where the situation gets complicated. Not all Smart Roadsters left the factory with 371568, and dealer servicing during the production era was inconsistent about updating firmware. Generally speaking:
- Late 2005 and 2006 build cars — particularly Brabus variants — are more likely to have 371568 already fitted.
- 2003 and early 2004 cars are very likely to be running an earlier firmware version.
- Mid-production cars (late 2004, 2005) can go either way depending on whether they received a dealer software update.
The only reliable way to know which firmware your ECU is running is to read it. You will need either a Smart-compatible diagnostic interface or access to a flash tool that can interrogate the MEG 1.1 and report the current software identifier. Reading your ECU’s current state before any firmware or map change is a step that should never be skipped — it tells you exactly what you are starting from and prevents costly mistakes.
How to Flash Firmware 371568
Flashing the MEG 1.1 to 371568 requires a compatible flash interface. Smart and Mercedes-Benz used the proprietary DAS/Xentry toolchain during the production era, but third-party options now exist for enthusiasts. The critical points to understand are:
FLASH vs EEPROM
The MEG 1.1 stores data in two separate memory areas. The FLASH holds the main programme code, including the firmware version identifier. The EEPROM holds adaptation values, immobiliser data and calibration trims that are specific to your individual car. When flashing 371568, you are updating the FLASH only. The EEPROM must be preserved, backed up and re-written correctly — if this data is lost or overwritten incorrectly, the car will not start. Understanding the distinction between these two memory types, and how SCN coding fits into the process, is covered in detail in our explanation of SCN coding, EEPROM and FLASH on the Smart Roadster ECU.
Voltage Stability
Never begin a flash procedure with a marginal battery. The ECU must remain powered continuously throughout the write process. A voltage drop mid-flash can corrupt the FLASH memory and render the ECU non-functional. Always connect a battery maintainer before starting, and do not attempt to flash in a vehicle with a battery that is more than a couple of years old without first testing its cold-cranking capacity.
Post-Flash Adaptation
After flashing, the gearbox will feel different — sometimes worse initially — until the ECU completes its self-adaptation cycle. Drive normally for at least 50 miles, including a range of urban, dual-carriageway and motorway conditions, before judging the results. The ECU learns clutch wear and actuator response over this period.
Firmware 371568 and Remapping: The Optimal Combination
For owners who are also interested in performance, firmware 371568 is particularly relevant because it serves as the recommended base for remapping the Smart Roadster. Our own maps — from the BASIC 90 HP through to the EVOLUTION 125 HP — are all developed and validated on 371568. Running an older firmware with a modern performance map can introduce timing and boost control behaviour that was not anticipated during the map’s development, potentially reducing reliability and performance consistency.
If you are considering a Stage 1 remap for your Smart Roadster, updating to 371568 first is not optional — it is a prerequisite. The gear change improvements and the performance gains then work in concert: faster shifts mean the engine spends less time in the torque-interruption window, so more of the power increase is actually felt on the road. For owners interested in what is achievable with our performance packages, our tuning packages page details the power levels and what each stage includes.
Common Questions About Firmware 371568
Will it fix my gearbox completely?
No. Firmware 371568 optimises the software side of gear changes, but it cannot compensate for worn mechanical components. If your gear motor is struggling, your selector drum is damaged, or your actuator is faulty, you will still experience problems after the update. Firmware is not a substitute for mechanical maintenance. If you are still experiencing sluggish or failed shifts after updating, the causes and remedies are covered in detail in the comprehensive guide to slow gear change fixes on this site.
Is it reversible?
Yes. Because the FLASH and EEPROM are separate memory regions, it is possible to re-flash to a different firmware version if needed. However, there is rarely any reason to go backwards from 371568. It is the best version available and there is no known scenario in which an earlier firmware performs better.
Does it affect the Brabus variants differently?
The Brabus SB2 and full Brabus variants use higher boost and different map parameters, but the underlying gear change calibration in 371568 applies uniformly across all power variants. The firmware interacts with the boost and fuelling maps separately from the shift calibration. Brabus cars on 371568 will show the same shift-speed improvements as standard 60kW cars.
The Bottom Line on Smart Roadster Firmware 371568
If your Smart Roadster is not already running smart roadster firmware 371568, updating it should be near the top of your maintenance and improvement list. The gear change improvements are real, measurable and consistently reported by owners who have made the switch. It is one of the few changes you can make to a Roadster that is entirely free of mechanical risk, requires no physical components and delivers an immediate, tangible improvement to the car’s most criticised characteristic. Combined with fresh gearbox oil and correct mechanical adjustment, it brings the Softouch system as close to its intended behaviour as it is possible to achieve through software alone.
