Civic 2016 1.5 Turbo CVT Europe - Flexfuel custom tune

[Ludo 262]

Hello,

As Flexfuel calibration was not available for my vehicle,
And despite many requests over several years ...
I finally made a custom tune.

This calibration was developed for a Honda Civic 1.5T CVT (2017) running French E85 (~60–75% ethanol).
The goal was drivability and stability, not maximum power.

Key Improvements :

• Smoother low-RPM drivability
The base map showed hesitation and “dead zones” around 1250–1750 rpm.
This calibration smooths torque and throttle response, making city driving more linear and predictable.

• Refined boost control for CVT
The TC Boost Command table was fully smoothed (no peak boost increase), reducing abrupt torque changes and improving CVT behavior.

• Ethanol ignition reworked for stability
Ignition transitions were smoothed instead of advanced.
Excessive ethanol ignition advance at very low rpm was reduced to improve low-speed stability and reduce ECU intervention.

• Fuel system behavior improved
Fuel pressure tracking is more stable, injector duty remains low, and no rail pressure drop is observed in WOT.
This reduces transient stress on HPFP and injectors.

• Cold start optimized for high ethanol content
Minor cold-start fueling adjustments improve starting without affecting warm operation.

Knock Behavior (Important)
A small, stable knock retard plateau (~4–6°) is still visible in part-throttle zones.
This behavior already exists in the stock/base map and is consistent with Honda’s anti-LSPI strategy.
- No knock escalation under WOT
- No negative impact on drivability
- Knock is now less intrusive and better controlled
- No Power Increase, No Added Risk
- No increase in peak boost
- No aggressive ignition advance
- Fuel system remains well within safe margins

Result
A more refined, smoother, and mechanically safer daily E85 calibration, especially suited for CVT.

"Use this calibration at your own risk"

[gantira]

Hello Ludo,

Thank you for sharing your calibration and the explanation behind the changes.

I noticed that your Civic ethanol menu appears to use the basic analog ethanol-input system and does not show CANFlex or Advanced Ethanol, which is very similar to the ethanol menu available on my 2022+ Indonesian Honda HR-V RV3 1.5T CVT.

Could you please explain what hardware you used for the real-time ethanol-content input?

Specifically:

1. Which flex-fuel sensor did you use?
- Continental/GM sensor?
- Do you know the exact part number?

2. Which ethanol analyzer/controller did you use to convert the sensor’s frequency signal into a 0–5 V analog output?
- Innovate MTX-D / ECF-1?
- Zeitronix ECA-2?
- A custom frequency-to-voltage controller?
- Another device?

3. Where was the analog ethanol signal connected?
- Was it connected to the ECU ECT2 input?
- Do you know the exact ECU pin used?

4. What voltage scaling did you configure in FlashPro?
- 0.00 V = E0 and 5.00 V = E100?
- Or did your controller require different voltage endpoints?

5. Does FlashPro display and log the measured ethanol percentage correctly in real time?

6. Once the ethanol input is enabled, does the ECU continuously interpolate and automatically apply:
- ethanol fuel compensation;
- ethanol ignition multiplier;
- WOT fuel compensation;
- cranking compensation;
- boost-by-ethanol limit?

7. Did you encounter any issue with low ethanol readings such as E0–E15, especially because the Honda ECT2 input may have an internal pull-up?

8. What happens if the sensor, analyzer, or analog signal wire becomes disconnected?
- Does the ethanol reading fall to E0?
- Stay at the previous value?
- Rise toward E100?
- Generate a DTC?

I am not asking for your proprietary ignition or fuel tables. I mainly want to understand the hardware architecture and the correct way to provide a reliable real-time ethanol signal to the ECU.

My HR-V calibration already has the same basic functions:

- Ethanol input enabled
- 0–5 V ethanol percentage conversion
- Ethanol fuel compensation
- Ethanol ignition multiplier
- Ethanol ignition compensation
- Ethanol cranking compensation
- Ethanol WOT fuel compensation
- Boost-by-ethanol limit

However, there is no CANFlex or Advanced Ethanol option, so your setup appears highly relevant to my platform.

Also, regarding the 4–6° knock-retard plateau you mentioned: was this the FlashPro “K.Retard” parameter itself, or the effective correction after it was multiplied by K.Control? Did the cylinder knock counts remain stable during sustained WOT?

Any photos, wiring diagram, controller settings, or hardware part numbers would be greatly appreciated.

Thank you.