Tuning

Getting Started

Things you need

1. KWP2000+ OBD cable
2. KWP2000+ flashing software
3. TunerPro
4. XDF file for the revision of ECU you are using. If you wish to use a different version software than your car came with, read this carefully.
   • XDF for M-box.
5. ECUFix (optional, some KWP2000 flashing software will do checksumming for you)

Fueling

• KRKTE - primary fueling
• KFKHFM - Correction map for MAF. If using an aftermarket intake system, this can be used to dial out fuel trim issues. In particular, if changing KRKTE for different fuel injectors makes it difficult to dial out both idle and part throttle LTFTs for a given target WOT AFR, you can log STFTs to determine where the MAF readings need tweaking.
• KVB - fuel consumption (MPG in cluster)
• MLHFM - compensate for MAF housing diameter. Some argue that using a different MAF housing (to extend the functional metered flow range) requires you to fix this so that measured load is "correct".
• KFLDBTS - requested lambda for component protection when calculated EGT is above TABGBTS (may require a lower TABGBTS if your MAF is not 100% compensated for in MLHFM)
• LAMFA - requested lambda when calculated EGT is below TABGBTS

Boost

• KFMIRL - specified load
• FLKDHBN - maximum requested pressure ratio
• LDRXN - maximum specified load
• KFTARX - IAT correction for maximum specified load

Cam changeover affect on requested boost

Motronic likes to change requested boost depending on cam position. While it may seem like a good idea in theory, in practice, abrupt changes in requested boost near the MAP limit can make the boost PID unhappy. When logging, you may see an odd notch in requested boost between 3000 and 4000 RPM. These maps are what is causing that notch

• KFPBRK - Correction factor for combustion chamber pressure
• KFPBRKNWS - Correction factor for combustion chamber pressure when NWS active
• KFPRG - Internal exhaust partial pressure dependent on cam adjustment when sumode=0
• KFURL - Conversion constant for ps->rl dependent on cam adjustment when sumode=0

Timing

• KFZW/KFZW2 - primary timing maps. ME7.1 has a two point variable cam timing system; there is a table for each cam timing state. When running elevated boost, you will have to significantly cut requested timing to prevent timing retard. Keep your worst case correction factors in the single digits, and always carefully monitor your knock voltages when tuning your timing.

Other niceties

Speed limiter

• VAVMX/VMAX - Speed limiter

Rev limiter

• NMAX - RPM limit
• NLLM - idle RPM

Left foot braking

Set either of these to maximum to prevent throttle cut when left foot braking:

• NWPMBBR - Minimum RPM for acc pedal value lockout on brake operation
• VWPMBBR - Minimum speed for acc pedal value lockout on brake operation

Knock control

Adjust these maps with care. Abusing any of them can cause severe detonation and probable motor damage

• KRFKLN - Ignition retard per knock event.
• KRALH - Load hysteresis. This adjusts how quickly timing will be restored as load changes.
• KRANH - Engine speed hysteresis. This adjusts how quickly timing will be restored as RPM changes.

Requested load cut on knock detection

• KFFLLDE - Factor for slow LDR intervention on rlmax via KR

Fuel enrichment on knock detection

• KFLAMKRL - Enrichment on ignition retard

Emissions

• CDKAT - Cat diagnosis in OBDII-Mode. Set to zero to disable rear cat DTC

References

Motronic abbreviations