Summary of Software

ProECU software has been introduced to allow reprogramming of the factory ECU in order to tune the necessary components of the calibration in order to allow for modifications and increases in power.  This is not a standalone repalcement ECU so you shouldn't run into the associated issues or disadvantages of setting up a purpose-built ECU and control system from scratch.

The software allows easy control over most factory parameters including:

• Boost Targets and wastegate control
• Target AFR
• Ignition Timing
• Fuel Delivery including fuel pump calibration (using the same style pump as OEM)
• Airflow Measurement and fuel compensation

Programming

For information on how to program as well as flash recovery, check out.

• ECU Programming Overview
• How to Recover an ECU
  
  

For more software guides check out:

• Software Help and How-To

Which ROM version to use?

All ROM versions are shown under HELP, FEATURE & LICENCE INFORMATION and SUPPORTED ECUs. Only use the ROM that is specified for your region.

Make sure you base your tuning on the latest ROM revision that is available. Hitachi are constantly developing and improving and bug fixing so make the most of their hard work. 

Compatible ROMs are shown in the ECU programming window, the latest ROM file to use is normally quite obvious through numerical and alphabetical increments, see below for some USA WRX examples, the LV9N_101C and 101D are the latest versions to use (CVT or MT dependant)

2015 USA WRX Manual Model – latest ROM to use at this time is LV9N101C and it has improved knock control.

2015 USA WRX CVT Model – latest ROM to use at this time is LV9N101C and it has improved knock control.

2015 USA Forester CVT Model – latest ROM to use at this time is LF61600B with improved knock control.

2014 USA Forester CVT Model – the latest ROM to use at this time is AF56C00B with many attempts to solve various different issues it seems. AF53100B to AF56700B are not listed for purpose of explanation simplicity.

Other regions worldwide comply with similar update structure, here we can see the latest EURO region ECU ROM for the 2013 Forester is the AF5G100H, which replaces the 100A, 100C, 100D and 100G earlier variants). See the Supported ECU list found in ProECU for further assistance.

While we do not always know what’s been changed on later revisions but Hitachi will be constantly fixing and improving the calibration and the code. We know some early Foresters have suffered from engine damage and that later ROM revisions can help avoid this problem so use the latest ROM available.

Tuning Guide

Turbo Dynamics

These maps control the rate at which the wastegate duty cycle is altered in order to produce the desired level of boost. These maps determine the percentage of wastegate duty that is added or subtracted from the current duty, based on the magnitude of error between actual boost and desired boost.  Small values in these maps will cause the boost to build very slowly, but are very safe, since there will be no over boost. Higher values in these maps will causes boost to rise more aggressively, but must be carefully set to ensure that over boost and oscillation do not occur.

Open - Closed Loop Control 

The Fuel Map – Open Loop Lo Det and Fuel Map – Open Loop Hi Det are the main tables that set the Target AFR and also determine if Closed or Open loop fuelling will be used:

• A 14.7 value in the Fuel Map Lo Det indicates that the ECU should work in a Closed Loop mode condition and the Target AFR value is selected from one of the maps called Fuel Map – Closed Loop #1 - #5 (FTST is working).
• A value lower than 14.7 Fuel Map – Open Loop Lo Det indicates that the ECU should work in Open Loop mode condition the target AFR value comes from the Fuel Map – Open Loop Lo Det map itself (FTST is NOT working).

When the ECU switches from a Closed Loop condition to an Open Loop then there are timers and transitional ramp rates that must be considered and appreciated.

Other important notes:

• If the ECU is in Closed Loop mode, then the Short Term Fuel Trim will be active.
• If the ECU is in Open Loop mode, then the Short Term Fuel Trim will not be active and FTST will show the Live Data logging parameter as zero.
• The AFR values shown in the Open Loop fuel maps will be achieved in open loop mode on a stock vehicle as these values are based on a stock intake and an accurately measured amount of airflow, so the correct amount of fuel volume will be injected to deliver the AFR in the Open Loop map.
• If the Intake has been replaced then the MAF scaling should be adjusted until the AFR value in the Open Loop map is roughly the same for a given RPM and Engine Load. Ensure that your actual engine load parameter shown in the data logging does not exceed the Engine Load Values shown in the X axis of the fuel map. If it does, then rescale your maps for the higher engine load that is achieved.
• Fuel trims in Open Loop can be disabled by setting the AF Correction #3 Target Compensation maps to zero.
• It's possible to use Closed-Loop at full load but we advise against doing so until further testing has been done.

Adjusting the Direct Injector Firing Angle

The Direct Injector Angle map (called Fuel Injection Angle Base) shows the Start Of Injection (SOI) angle in crankshaft degrees before TDC (spark plug firing).

This will be followed by the End Of Injection (EOI) when the Direct Injector will actually close. The time period that the DI is actually open for is controlled by the Fuel Map Target AFR and how much fuel volume is required to achieve that AFR for a given fuel pressure.

The Fuel Injection Angle map shows the SOI angle is crank degrees before TDC spark firing (not TDC valve overlap). 

• 180 deg will mean SOI will commence at BDC (end of the Induction stroke and start of the Compression stroke).
• 270 deg will mean SOI will commence half way down the Induction stroke with the piston heading down for BDC.
• 360 deg will mean SOI will commence at TDC during Inlet and Exhaust valve overlap phase (the start of the Induction stroke and end of the Exhaust stroke).

There are four main logging parameters to consider here:

• Fuel Injection Advance – This is the crank angle (deg) before TDC (spark plug firing) that the DI will commence SOI.
• Fuel Injection #1 Pulse Width – the total time period is (ms) that the DI is open for.
• Fuel Injection End to Spark – This is the time period (ms) between the EOI and the spark plug firing (Ignition Timing), there must always be a time period between EOI and the spark plug firing.
  
  

As the DI can only inject during Induction and Compression strokes the total amount of DI open time is half of what a port injector could be (as port injectors can be open during all four strokes).

But the DI open time period is also limited by:

• Valve Overlap – If DI starts to early then the fuel could end up in the exhaust system.
• Ignition Timing – EOI must happen before the spark plug fires.
  
  

So valve overlap needs to be considered before the SOI, at high RPM (6000+rpm) you would expect to see the Direct Injection Angle (SOI) set at 340 to 370deg, this is during valve overlap but the piston is moving so fast that no fuel will travel into the exhaust system. In addition the Injection phase must be finished (EOI) before the spark plug fires, remember that the spark plug often fires BEFORE TDC and an Ignition Timing value of 25deg will mean the piston is still rising on the compression stroke when the plug fires so this limits the total time period that the Injector can actually inject. For tuning we need to be able to measure the time period left between EOI and the spark plug firing, this is the logging parameter called ‘Fuel Injection End to Spark’, this is the time period (ms) between EOI and the spark plug firing.

This is a very important logging parameter and it’s logged by default in the latest RRFF, monitor this closely whilst tuning.  The actual DI open time is dynamic, the AFR Target is constantly changing due to closed loop control, fuel pressure and even knocking.  The Ignition Timing is also dynamic with Advance Multiplier and Knocking Correction all affecting the final spark advance angle and limiting the available time period that the DI can inject for.

The two log file screen shots above show the ‘Fuel Injection Spark to End’ as 1.8ms at 6000rpm and the ‘Fuel Injection Pulse Width’ is open for 6.91ms, the DI firing angle at 327deg BTDC. So at 6000rpm the engine take 10ms for one revolution (5ms per stroke), so the maximum DI period (Fuel Injection Pulse Width) would be 10ms. 

Allowing for valve overlap (DI angle at 327deg BTDC) and spark advance at 3.5deg BTDC then 10ms DI Open Time is simply not possible and we can see the free time between EOI and Ignition Timing firing is down to 1.8ms (Fuel Injection End to Spark logging parameter).

If the ‘Fuel Injection End to Spark’ time period is less than 0.5ms then misfiring will be experienced as the DI is open whilst the spark plug fires!  This can also cause damage to the injector.

This logging parameter should never be less than 1ms in our opinion to give the fuel time to mix before the spark event. If more fuel is required then you can tweak several factors to increase this time period (though all have limiting factors):

• Increase Fuel Pressure by 1MPa so the Fuel Injector open time period (ms) will be less due to the higher demanded fuel pressure, the Fuel Pressure can only be increased by a small amount before the high pressure fuel pump is beyond capacity.
• Increase the Fuel Injector Angle map values at higher RPM which will start the injection period earlier (only at the RPM where there is no free time left), the SOI angle can only be pushed so far before it will inject fuel when the exhaust value is still open (though reducing the values in the Exhaust VVT map will means the Exhaust VVT closes earlier so less chance of fresh charge entering the exhaust.
• Lean the Fuel Map slightly which will reduce the DI open Time period though watch for knocking.
• Reduce Target Boost Pressure so less fuel injector open time is required.

Tweaking all of the above should ensure you have sufficient ‘free time period’ for maximum power.

Idle

Controlling the Idle speed of an engine is a difficult task and the factory ECU has many targets and compensations to achieve this. The Idle Target maps set the target Idle Speed for many different modes like drive, neutral, after starting, engine hot, load on (alternator or headlights etc). It is advised that you adjust all Idle maps by the same amount or simply set them all the same to avoid discrepancies in the idle engine speed.

Target Idle

Desired engine idle speed for a given coolant temperature. If you wish to increase Idle Speed by 150rpm then add 150rpm to all Target Idle maps when coolant temp is over 50deg C.

Idle Stability Control

• axis is RPM idle error
• axis is rate of change of engine speed

This map is used for Idle Speed error compensation, making the values bigger will make the Idle Speed error more aggressive for correction.

Ignition

Advance and Timing Limits

The DIT runs very little timing advance compared to older STI models and even the more recent BRZ/ FR-S/86 models. Even with its lower 10.6:1 Compression Ratio the new DIT engine design does not allow us to run the sort of timing advance you would expect on a BRZ FI model or a STI so watch carefully. 

The Intercooler seems particularly inefficient and you can watch the Charge Air Temp climb during a power run or pull on the road. Running a richer AFR will also help keep the engine quiet.

Timing Map Differences

In “Mode 1”, the ECU will use the original Base Ignition Timing and Ignition Advance map strategy labelled as TGV and VVT ON/OFF. In mode 2 and 3, the ECU will use the new singular RaceROM Ignition Timing and Ignition Advance maps labelled Mode2 and Mode3 respectively. 

Ignition Timing Control

The Ignition control and dynamic advance system is very similar to older Subaru’s from 2005 to 2015. The DIT engine runs very little Igniting advance on full load compared to other Subaru’s like EJ25 or even the high compression BRZ/GT86 with a turbo fitted! 

The DIT is very sensitive to Ignition timing and like most Subaru’s it runs on the edge of knock most of the time.

Spending time to understand the Ignition control is really important so you can understand what’s going on and make a good safe calibration.

See the log file above, the Yellow line (Ignition Timing) is only 4.5deg BTDC at 5500rpm and the ignition timing is actually -4deg (ATDC) at peak torque.  The knock control and fine learning are very active and can at times seem too sensitive. Charge air temp is again a significant and limiting factor and the factory Intercooler becomes saturated on two simple power runs. Charge Air Temps over 70deg C are not uncommon at higher RPM.

In this next example you can see the Fine Learning (Knock Correction Retard Amount AK) trying to advance the Ignition and raise the Advance Multiplier (down at only 0.38).  

The Cyan coloured line shows AK cycling and building advance from -1.5 deg to a positive +1deg only to knock then start the cycle all over again.

You can also see the Red coloured line Ignition Timing Learned value (AT) increasing and decreasing as the Fine Learning is added and subtracted whilst exploring the knock limit.

In this next example you can see the engine is held on load, stead state and that the Advance Multiplier is climbing from 0.44 to 1 over a 70 second time period. You can see the Ignition Timing Learned (AT) also increasing from 3.5 to 7deg over the 1 minute period. Remember that AT is the output of the Ignition Advance map multiplied by the AM, so as the AM rises so does the Ignition Learned value. As a result the Ignition timing advanced from 5.5deg to 9deg.

You can see that the Knock Correct (AK) value was positive (greater than zero) whilst the AM was climbing, this is the fine learning /dynamic advance working. AK adds positive advance and in the vent of no knocking the AM climbs.

Here are some facts to consider:

• The Ignition Advance maps are multiplied by the AM before being added to the Ignition base maps, so larger values in the Ign Adv maps will have a greater effect on the ignition timing when the AM changes, smaller values in the Ign Adv maps will have a smaller effect on the ignition timing when the AM changes.
• Different Knock Sensitivity maps will be selected relative to the Advance Multiplier (maps called Knock Sensitivity Ign Adv. Hysteresis and Threshold).
• On WRX the Ignition Advance Maps #1 and #2 are added together then added to the base map relative to the 2d maps called Ignition Advance – AM Factor #1/#2.
• Make sure that the actual Engine Load does not exceed the X axis Engine Load scaling on the Ignition maps, if it does then rescale all the Ignition maps.

The thresholds above control the minimum and maximum Engine Speed (RPM) and Engine Load that the ECU is allowed to calculate and store the Fine Ignition Learning, these can be used to prevent the ECU from removing and stored Ignition Retard unnecessarily.

Ignition Base Map

The ECU selects an Ignition Base Map depending on the current VVT and TGV status:

• TGV Closed, VVT Off
• TGV Closed, VVT On
• TGV Open, VVT Off
• TGV Open, VVT On
  
  

Ignition Advance

The Ignition Advance map is added to the Ignition Base map relative to the LIVE DATA parameter called Advance Multiplier (AM). The Ignition Advance map is used as a coarse Ignition adjustment to advance and retard the Ignition timing for changing conditions like fuel quality, ambient temperature and altitude. On some models the Ignition Advance maps may be added together then added to the Ignition Base map so take care when adjusting these maps and watch carefully to understand the control.

The factory Ignition Advance map is calibrated to advance and retard the ignition timing by a greater degree in certain areas of the map (as seen in the next screen shot).

This is to ensure when the engine is knocking (and the AM decreases) that more Ignition timing is removed from areas where the engine is more susceptible to detonation (like peak torque). Areas where the engine is least likely to detonate the values are smaller (like light load).

The X and Y axis scaling can be adjusted to suit higher RPM or higher Engine Loads if required.

The output of the Ignition Advance map is important and can be seen and logged in LIVE DATA as Ignition Timing Learned parameter.

So ‘for explanation purpose only’, if the Ignition Advance map was filled with 12 deg then the Ignition Timing Learned value would read 12 deg in LIVE DATA (assuming the AM is 1).

If the AM is 0.75 then the Knock Correction Learn Value would read 9 deg (12 * 0.75 = 9 deg). If the AM is 1 but the Ignition Timing Learned value is less than 12 deg at some points during a power run this indicates historical knocking events that have been Learned (see below for further information).

NOTE: In “Mode 1”, the ECU will use the original Base Ignition Timing and Ignition Advance map strategy labelled as TGV and VVT ON/OFF.

In mode 2 and 3, the ECU will use the new singular RaceROM Ignition Timing and Ignition Advance maps labelled Mode2 and Mode3 respectively. So the factory multiple Ignition control for different VVT/TGV conditions is not used in Mode 2 and Mode 3.

Any Ignition Timing Compensations for Air Temp or transient will still be included in the Ignition Timing compensation.

Advance Multiplier - Coarse Correction

The Advance Multiplier (AM) is dynamic and will change relative to the current amount of engine knocking (detonation). If the engine is knocking frequently and consistently then the AM will be low, if there is no knocking then the AM will be high. The AM moves between 0 and 1. The highest advance multiplier number obtainable is 1.  If the AM is 0 then NONE of the Ignition Advance map will be added to the Ignition Base map.  If the AM is 1 then ALL of the Ignition Advance map will be added to the Ignition Base map. If the AM is 0.73 then 73% of the current Ignition Advance map value will be added to the Ignition Base map.

Advance Multiplier - Initial

This is the base default setting for the advance multiplier after ECU Programming or ECU Reset. This can be increased to 1 for tuning purpose so that 100% of the Ignition Advance map is added to the Ignition Base map. It is advised to reset back to its default value on the final flash of the ECU.

Intake Air Temp Compensations

The 2d map called “Ignition Timing – IAT Compensation” will retarded the Ignition Timing at high intake air temps, especially over 40deg C. The amount of retard applied is controlled by the 3d map called “Ignition Timing – IAT Compensation Multiplier”.

This multiplier map shows that very little retard will be applied at lower load regions but the majority of retard will be applied on full load (where the engine will be most susceptible to detonation)

Ignition Retard #1 - #5

This is per gear Ignition retard amount applied to the current Ignition Timing.

The maps are difficult to document on CVT models due to the complexity of the CVT control. The Ignition Retard map chosen depends on vehicle speed and engine rpm.

The current Ignition Retard map selected can also change depending on the current SI Drive mode selected (as additional gears can be added depending on the mode).

You should test your results to be sure of the exact control on your particular vehicle.

Notes from our CVT-Equipped Legacy DIT:

Retard maps #1- #4 are used in their respective gears 1-4 in ALL of the SI drive modes.

Map #5 is used in both S and I mode for 5^th gear but not in 6^th gear.  It is also used for 5^th and 6^th gear in Sport # mode.

It does not appear that any of these maps are being used in the highest gear ratio 7^th gear.  Remember that the current gear judgement is altered by SI Drive selection (as Sport # offers an additional 7^th or 8^th gear)

Ignition Timing calculation

The final Ignition Timing calculation is computed like this:

It’s a very active and dynamic control strategy that will constantly adjust the ignition timing but it should not be fully trusted to ‘control the ignition’. The final Ignition Timing logging parameter will include any compensations or corrections that have been made by the above maps.