How can you tell whether a previous ECU remap actually increased your car's performance? A tuning certificate showing higher horsepower figures is not proof that the engine software was modified or that the advertised gains were achieved. This Volvo XC90 is a clear example of why independent testing matters.

The owner had previously visited another tuning company and received documentation claiming an increase in engine power and torque. However, the vehicle did not feel as responsive as expected. To find out what was really happening, the owner brought the Volvo to AutoChip for an ECU software inspection and a dynamometer test.

What did the previous tuning certificate claim?

According to the document supplied by the previous company, the Volvo XC90's power output was supposed to increase from 185 to 205 HP, equivalent to 136 and 151 kW respectively. The quoted peak torque figures were 400 Nm before tuning and 450 Nm afterwards. The document also suggested an improvement in acceleration from 0 to 100 km/h, reducing the time from 11.5 to 11 seconds.

Those figures sounded promising, but the owner had doubts about the actual improvement. The only meaningful way to investigate was to examine the ECU calibration and measure the vehicle's performance.

Initial dyno test and Bosch EDC16C31 software inspection

We placed the Volvo XC90 on the dynamometer and carried out an initial power measurement. The result was approximately 179 HP and 376 Nm of torque, significantly below the previously claimed tuned figures of 205 HP and 450 Nm.

We also inspected the software file from the Bosch EDC16C31 engine control unit. The inspection revealed that the ECU contained the original factory calibration rather than the modified software described in the previous tuning documentation.

In other words, the certificate did not reflect the actual condition of this vehicle. The initial dyno figures were close to the original power output, while the software inspection showed that the factory ECU calibration was still present.

Stage 1 ECU remapping with measured results

After completing the initial checks, AutoChip carried out a Stage 1 ECU remap. This involves optimising engine management parameters to improve performance while taking the vehicle's mechanical condition and operating characteristics into account.

The aim of a well-developed Stage 1 calibration is not simply to produce an impressive peak horsepower figure. The shape of the power and torque curves also matters, because it affects how the engine delivers performance across its operating range.

Once the ECU software had been modified, we performed another dynamometer test. The resulting figures were 223 HP and 400 Nm of torque.

• Before AutoChip Stage 1: approximately 179 HP and 376 Nm.
• After AutoChip Stage 1: 223 HP and 400 Nm.
• Measured improvement: approximately +44 HP and +24 Nm.

These were actual measurements taken from the same vehicle before and after the software changes, rather than estimates from a generic tuning chart. The dyno results also provided power and torque curves for comparing engine behaviour throughout the measured RPM range.

Why transmission behaviour matters during dyno testing

During the measurements, the technician noticed minor fluctuations in the plotted curves. He suggested that some transmission slip might be contributing to the irregularities and indicated that the gearbox would benefit from further attention.

These fluctuations alone do not establish a specific gearbox fault. A separate inspection would be necessary to determine their cause. Nevertheless, transmission condition is an important consideration during dyno testing because irregularities in torque transfer can affect the recorded curves.

Professional ECU tuning means verifying the results

This Volvo XC90 demonstrates why a tuning certificate should never be treated as a substitute for proper testing. Claimed figures, estimated improvements and measured performance are not the same thing. Verifying an ECU remap requires checking the software and comparing results before and after the work.

The AutoChip service package described in the video includes dynamometer measurements, diagnostic data logging, ECU file inspection and software optimisation. At the time of recording, the technician quoted a price of €250 including VAT for this package. Current pricing should be confirmed separately.

Customers can receive measured performance data, including power and torque graphs, providing a clear basis for assessing the results. The earlier certificate's claimed improvement in 0–100 km/h acceleration was not independently tested in this case.

For this particular Volvo XC90, the confirmed Stage 1 result was 223 HP and 400 Nm, measured on the dynamometer. If you are unsure whether a previous ECU remap was carried out correctly, or simply want to know your vehicle's actual power output, AutoChip can help with ECU software inspection and dyno testing. The accompanying video shows the Volvo's testing process and the comparison between the original and tuned results.