ECU remapping does not always have to focus on extracting the maximum possible horsepower. For a vehicle used every day, a moderate Stage 1 calibration can be a more appropriate choice, improving engine response and available torque while taking the vehicle's mechanical condition and existing exhaust aftertreatment systems into account.

A 2011 Mercedes-Benz C-Class equipped with a 2.2 CDI diesel engine arrived at AUTOCHIP.LV for a Stage 1 ECU remap. The vehicle uses a Delphi CRD3 engine control unit and retained its original exhaust aftertreatment equipment, including the diesel particulate filter and EGR system. According to the technician, none of these emissions-related functions had previously been disabled in the ECU software.

The objective was to provide a useful improvement for everyday driving rather than pursue the highest possible power figure. Following the calibration, measured output increased from 157 to 180 hp, while torque rose from 473 to 546 Nm. Both configurations were tested on the AUTOCHIP.LV chassis dynamometer.

Mercedes 2.2 CDI and the Delphi CRD3 ECU

Mercedes-Benz CDI diesel engines use electronically controlled Common Rail fuel injection. The engine management system calculates torque demand and controls fuel delivery, injection parameters and other operating functions.

Working together with turbocharger control and sensor information, these strategies determine how the engine responds to accelerator input and delivers torque across its operating range.

The vehicle in this case is equipped with a Delphi CRD3 engine control unit. Correct identification of the ECU and its software configuration is important when developing an individual calibration.

Stage 1 remapping generally involves adjusting engine management software to improve performance while retaining the existing main engine hardware. It does not mean that every vehicle should receive identical boost pressure targets, fuel delivery settings or torque limits.

For this Mercedes, the priority was a balanced power increase with smooth torque delivery, suitable for normal road use.

Baseline dynamometer measurement — 157 hp and 473 Nm

Before modifying the ECU calibration, the Mercedes underwent a baseline power measurement on the AUTOCHIP.LV four-wheel-drive dynamometer.

Initial measured output:

• Engine power: 157 hp.
• Maximum torque: 473 Nm.

These figures are the actual measurements recorded for this vehicle with its original calibration, rather than values taken from a manufacturer specification sheet.

Establishing a baseline is an important part of professional ECU tuning. Without an initial power measurement, it is difficult to determine exactly how much performance has changed after the remap.

A dynamometer also provides information about the shape of the power and torque curves. This matters because smooth, predictable power delivery is often more useful during everyday driving than an isolated peak horsepower figure.

Engine data logging before tuning

In addition to dynamometer testing, AUTOCHIP.LV used engine data logging to examine operating parameters under load.

Conventional fault-code diagnostics can identify stored errors, but they do not always reveal how the engine behaves during acceleration or under changing load. Data logging allows the technician to review live operating values and compare actual measurements with ECU requests.

During the Mercedes inspection, the technician referred to several important parameters:

• Engine temperature readings.
• Atmospheric pressure and other pressure measurements.
• Requested and actual fuel pressure.
• Fuel injection system operating parameters.
• Injection duration.
• Turbocharger boost pressure.
• Engine torque-related values.

Comparing requested and actual values can provide useful diagnostic information. For example, the Common Rail system should maintain fuel pressure in accordance with the engine management strategy under the relevant operating conditions.

Likewise, boost pressure data can indicate whether the turbocharger is following the ECU's requested values or whether significant deviations require further investigation.

For this vehicle, data logging and parameter review formed part of the tuning process. However, the full numerical results for all the diagnostic channels are not presented in the video.

Stage 1 with the DPF and EGR systems retained

One of the defining aspects of this project was that the Mercedes retained its exhaust aftertreatment systems.

The diesel particulate filter (DPF) captures soot particles produced during diesel combustion. The exhaust gas recirculation (EGR) system redirects a controlled amount of exhaust gas into the intake under certain conditions to help reduce nitrogen oxide formation.

When developing a calibration for a vehicle with these systems, it is important to consider their operating requirements alongside engine performance.

Excessive fuelling and increased soot formation can place additional demands on the DPF. Changes to combustion and turbocharger operation can also affect exhaust temperatures and other relevant operating conditions.

For this Mercedes, AUTOCHIP.LV selected a moderate Stage 1 calibration rather than attempting to maximise power output. The intention was to improve engine response and torque while keeping the existing emissions equipment in place.

Retaining the DPF and EGR does not, by itself, demonstrate that every component is in perfect condition or that the vehicle has passed a complete emissions assessment. These matters require appropriate diagnostic checks and, where necessary, emissions measurements.

Stage 1 dyno results — 180 hp and 546 Nm

After the ECU software was calibrated, the Mercedes underwent a second dynamometer test.

The results confirmed an increase in both measured engine power and torque.

Before-and-after comparison:

• Power before Stage 1: 157 hp.
• Power after Stage 1: 180 hp.
• Power increase: +23 hp.
• Torque before Stage 1: 473 Nm.
• Torque after Stage 1: 546 Nm.
• Torque increase: +73 Nm.

On the dynamometer graph, the red curve represents the original engine calibration, while the blue curve shows the result after AUTOCHIP.LV tuning.

The technician highlighted the smooth shape of the revised power and torque curves. The measured increase was consistent, without pronounced unwanted dips or abrupt fluctuations in the displayed graphs.

This was an important part of the result because usable performance depends not only on peak output but also on how the engine develops power across the rev range.

The additional 73 Nm of torque may improve the vehicle's response when accelerating from cruising speeds or preparing to overtake. However, safe overtaking still depends on road conditions, available distance, traction and driver judgement.

No separate acceleration-time or fuel consumption measurements were provided, so specific improvements in those areas cannot be claimed.

Reviewing engine parameters after the remap

Following the final dynamometer measurement, the technician explained that the recorded data logs would be examined in more detail on a larger screen.

The purpose of this additional analysis was to compare actual engine operating values with the targets specified in the revised calibration.

Such checks are particularly relevant for vehicles retaining their DPF and EGR systems. Increased engine output should be considered alongside fuel pressure regulation, boost control, injection behaviour and operating temperatures.

The video confirms that the Stage 1 calibration was completed, the final power measurement was taken and engine data logs were recorded. However, the complete results of the planned detailed follow-up analysis are not shown.

It would therefore be inaccurate to claim that every individual operating parameter was fully verified or that long-term performance under all driving conditions had been established.

Why choose a moderate Stage 1 instead of maximum power?

Maximum power and the most suitable everyday calibration are not necessarily the same thing.

Higher output can improve acceleration, but it also changes the demands placed on engine and drivetrain components. The appropriate performance target should therefore reflect the vehicle's condition, configuration and intended use.

According to the technician, a more powerful calibration would have been possible for this Mercedes. Nevertheless, the achieved 180 hp and 546 Nm were considered appropriate for the owner's everyday driving requirements.

Rather than focusing solely on the highest possible dynamometer figure, the chosen calibration prioritised a balanced increase and smooth delivery.

Conclusion — Mercedes-Benz C-Class 2.2 CDI Stage 1

Following the Stage 1 ECU calibration, the 2011 Mercedes-Benz C-Class 2.2 CDI with a Delphi CRD3 control unit achieved 180 hp and 546 Nm on the dynamometer.

Compared with its initial measurements of 157 hp and 473 Nm, this represented an increase of 23 hp and 73 Nm.

The vehicle retained its DPF, EGR and other original exhaust aftertreatment equipment. The dynamometer graphs showed a smooth improvement in measured output, while engine operating data was recorded for further detailed review.

This project illustrates how a moderate, individually developed Stage 1 calibration can provide measurable performance gains without requiring the removal of factory emissions equipment. The accompanying AUTOCHIP.LV video shows the dynamometer measurements, diagnostic data and the results of the ECU tuning process.