So, you just got a new Accessport. You found the perfect spot to mount it and are ready to start monitoring engine parameters. Now the question is what 6 gauges do you choose and what does this information tell you. These are great questions and are very common with many of our customers after their dyno tune.

This post will detail some of the best gauges to monitor on your Accessport along with typical numbers you will see. We will also go over what gauges dont offer to much value for day to day monitoring. With this new found knowledge your Accessport will no longer be an “Anxietyport”. You can drive your car with confidence and truly enjoy the experience.

Recommended Gauges:

• AF Correction 1
• AF Learning 1
• Boost
• Coolant Temperature
• DAM, Dynamic Advance Multiplier
• Feedback Knock
• Fine Knock Learning
• Intake Temperature Pre Turbo or Intake Temperature Manifold if applicable. (2015+ WRX)

If you are Flex Fuel tuned other good monitors are:

• Ethanol Final
• Fuel Pressure Final

Some cars have a boost gauge on the dash or an aftermarket gauge. You can ditch the boost in favor of a different gauge. I know that I list more than 6 monitors but any of the listed are good to monitor.

Non-Preferred Gauges

These are common gauges we see customers monitoring that don’t really mean much unless you are looking for a specific problem. When tuning the engine some of these offer needed info but for day to day monitoring they don’t offer much for useable data.

• Battery Voltage – Unless you are having charging/starting issues this doesn’t mean much.
• Dynamic Advance Adder (A and B) – This is a multiplier applied to the “Dynamic Advance Adder Max” Table. This is not the final DAM.
• Dynamic Advance Final -This is the final dynamic advance that makes up a portion of total timing. This is not the final DAM.
• Dynamic Advance Learned – Dynamic advance map value with only the following learned knock corrections applied: dynamic advance multiplier (DAM) and fine knock learning correction. This is not the final DAM.
• Fuel Pump Duty – This shows the fuel pump duty commanded by the ECU. 100% does not mean you are using 100% of the fuel pump. This is a common misconception.
• Ignition Timing – This is the total ignition timing after all corrections and compensations for cylinder 1. Unless you specifically know what the timing should be this value isn’t very helpful. This value will vary greatly from -20 to 70 degrees BTDC.
• Injector 1 Pulse Width – This is the final injector pulse width commanded by the ECU. Values will vary widely from as little as .3 to 20ms.
• Injector Duty Cycle – This is the amount of time per engine cycle the ECU is commanding the injectors to be open. This value can exceed 100% if the tune is set up incorrectly.
• Mass Airflow – Final mass airflow (in grams per second), as determined by the ECU. This value can vary greatly from 1 to 300+ g/s depending on the power of the car.
• Primary Ignition – Primary ignition timing advance as determined by the ‘Primary Ignition’ table(s). This is before any corrections or compensations.
• Wastegate Duty Cycle – Final wastegate duty cycle as determined by the ECU’s boost control logic. This value can vary from 0 to 90% and unless you know what you are looking for is not very helpful.

Below are some short descriptions and what values you should expect to see for different gauges.

Accelerator Position

Expected Values – All Models

This is the Accelerator Pedal Angle Percentage as determined by the Accelerator Position Sensor. Your right foot will control this value.

AF Correction 1

Expected Values – 04-21 STI, 02-14 WRX, 05-12 Legacy/Outback GT, 04-13 Forester XT 

Expected Values – 15+ WRX, 14-18 Forester XT, 19-22 Ascent

This is the Short Term or Immediate Correction. This correction is based on the difference from the Closed Loop Fuel Target and what the AF Sensor 1 Ratio is reading (Front O2). Positive values indicate fuel is being added. Negative values indicate fuel is being removed. This value can vary widely from +35% to -35% depending on the ECU.

Sudden throttle changes can and will cause high values for a few seconds and it should stabilize in about 30 seconds. If values are consistently high it can be an indication of a vacuum leak, boost leak, Dirty MAF sensor, wrong fuel for tune, or other mechanical issues.

For the 15+ WRX and a properly set up tune you can have +/- 10% at full throttle. All other models, with a properly set up tune should read 0% at full throttle.

AF Learning 1

Expected Values – 04-21 STI, 02-14 WRX, 05-12 Legacy/Outback GT, 04-13 Forester XT 

Expected Values – 15+ WRX, 14-18 Forester XT, 19-22 Ascent

This is the Long Term or Learned Correction. This correction is based on AF Correction 1 values. If the AF Correction 1 values are consistently high or low for long enough they can be learned by this monitor. Positive values indicate fuel is being added. Negative values indicate fuel is being removed.

This monitor will move slowly over time. It is normal for this monitor to have a value and to not be 0. If values are more than +/- 12-15% for a day or two it can be an indication of a vacuum leak, boost leak, Dirty MAF sensor, wrong fuel for tune, or other mechanical issues.

For the 15+ WRX and a properly set up tune you can have +/- 10% at full throttle. All other models, with a properly set up tune should read 0% at full throttle.

AF Sensor Ratio 1

Expected Values – 04-21 STI, 02-14 WRX, 05-12 Legacy/Outback GT, 04-13 Forester XT 

Expected Values – 15+ WRX, 14-18 Forester XT, 19-22 Ascent

This is the Air Fuel Ratio based on the Front O2 Sensor. This value can vary widely depending on engine conditions. With 14.7 being considered the middle of this gauge, the lower it reads (Richer AFR) the more fuel that is being consumed. The higher this gauge reads (Leaner AFR) the less fuel is being consumed.

15+ WRX –

With a properly set up tune that runs full time closed loop fueling, this should read close to what the Closed Loop Fuel Target gauge reads at all engine conditions except when engine braking. The 2022+ WRX comes from the factory with full time closed loop fueling so even a stock tune should read close to the closed loop fuel target except when engine braking. In engine decel conditions, i.e. clutch pedal not depressed and decelerating in gear (engine braking) this gauge will read 17.0-22.0 AFR. This is totally normal and happens because the fuel injectors are shut off and engine braking. Engine braking will help increase fuel economy.

All other models-

At idle and cruise it will typically read 12.5-14.7 AFR. Typically this gauge will read close to what the Closed Loop Fuel Target is. At full throttle it will read 12.0-11.02 AFR, 11.02 is actually the richest this gauge can read. Because the Front O2 sensor is in the header before the turbo it is not accurate under boost. The exhaust gas back pressure causes the reading to be incorrect. It is NOT a good gauge to use to determine if your fueling is correct at full throttle. In engine decel conditions, i.e. clutch pedal not depressed and decelerating in gear (engine braking) this gauge will read 17.0-20.0 AFR. This is totally normal and happens because the fuel injectors are shut off and engine braking. Engine braking will help increase fuel economy.

AVCS Exhaust Right or Left (where applicable)

Expected Values – 08-21 STI

Expected Values – 15+ WRX, 14-18 Forester XT, 19-22 Ascent

This is the Exhaust Active Valve Control System (AVCS) Camshaft Position.

Logging both the right and left values can be helpful if you are trying to diagnose P000B, P000D, P0014, P0017, P0019, P0024, and P0336. Both cams should read very similar values.

 AVCS Intake Right or Left (where applicable)

Expected Values – 04-21 STI, 06-14 WRX, 05-12 Legacy/Outback GT, 04-13 Forester XT 

Expected Values – 15+ WRX, 14-18 Forester XT, 19-22 Ascent

This is the Intake Active Valve Control System (AVCS) Camshaft Position.

Logging both the right and left values can be helpful if you are trying to diagnose P000A, P000C, P0011, P0016, P0018, P0021, and P0336. Both cams should read very similar values.

 Barometric Pressure

Expected Values – All Models

This is the Barometric Pressure based on the Barometric Pressure Sensor. This value will change slightly with the weather or if you go up or down in elevation.

2002-2006 WRX, 2004-2006 STI / Forester XT, 2005-2006 Legacy/Outback GT, 2010-2012 Legacy GT

This sensor is located internally on the circuit board of the ECU.

2007-2014 WRX,  2007-2021  STI, 2007-2013 Forester XT / 2007-2009 Legacy/Outback GT

This sensor is part of the Air Pump System commonly deleted when air pumps are deleted but is critical to have for proper idle and drivability. Boost is compensated from this sensor. If you have P2431, P2432, P2433 codes this sensor is either bad or deleted and should be re-installed / replaced.

Battery Voltage

Expected Values – All Models

This is the Battery Voltage as determined by the battery voltage input to the ECU. If battery voltage is below about 12.6v while the engine is running that may be an indication of the charging system not working correctly.

Boost

Expected Values – All Models

This is the Boost as determined by the Manifold Absolute Pressure Sensor. This value will vary widely and peak value will be dependent on the tune flashed to the ECU.

Typical values are as follows:

2002-2014 WRX boost targets, Stock – 11-13psi, STG 1 – 14-16psi, STG 2 – 16-18psi
2004-2021 STI boost targets, Stock – 14psi, STG 1 – 16-18psi, STG 2 – 17-19psi
2015-2021 WRX boost target, Stock – 15psi, STG 1 – 19psi, STG 2 – 19-20psi
2022+ WRX boost target, Stock – 12psi, STG 1 – 14psi, STG 2 – 17-20psi

Boost Target Final Rel

Expected Values – All Models

This is the Boost Target after all boost target compensations have been applied.

Depending on how the tune is set up this value may not match the actual boost level.

Calculated Load

Expected Values – All Models

This is the Engine Load, in grams per crankshaft revolution, as calculated by the ECU.

This value will vary widely throughout the engine operation.

Closed Loop Fuel Target

Expected Values – 04-21 STI, 02-14 WRX, 05-12 Legacy/Outback GT, 04-13 Forester XT 

Expected Values – 15+ WRX, 14-18 Forester XT, 19-22 Ascent

This is the Closed Loop Fueling Target  after all compensations have been applied. If AF 1 Corrections are happening the ECU is using this value as a target to try and keep the AF Sensor Ratio 1 (Front O2 Sensor) reading the same value.

This value will vary widely throughout the engine operation.

All models except the 15+ WRX-

This value is not used as a target when full throttle. The Front O2 sensor is located in the header before the turbo and the backpressure causes the sensor to read inaccurate. When full throttle the value will not be accurate to actual AFR.

15+ WRX –

If the tune is set up correctly this value should match closely to actual AFR.

Clutch Switch

Expected Values – All Models

This is the Clutch Pedal Switch input to the ECU. This value is used in the logic for launch control and flat foot shift.

Commanded Fuel Final

Expected Values – 04-21 STI, 02-14 WRX, 05-12 Legacy/Outback GT, 04-13 Forester XT 

Expected Values – 15+ WRX, 14-18 Forester XT, 19-22 Ascent

This the Final Commanded Fuel Target. This is after all compensations.

This value will vary widely throughout the engine operation.

All models except the 15+ WRX-

This value is the Final Fueling Target when in Open Loop fueling. Since the value is a modifier of fuel injector pulse width it may not be a accurate representation of what the actual fuel target is when full throttle or in open loop.

15-21 WRX –

If the tune is set up correctly this value should match closely to the Closed Loop Fuel Target. On a stock tune this is the fueling target when in Open Loop or full throttle.

Coolant Temp

Expected Values – All Models

This is the Engine Coolant Temperature from the Coolant Temperature Sensor.

Monitoring Coolant Temps via the Accessport can be very helpful. With the information below you can see that the gauge on the instrument cluster isn’t the most accurate and you could have coolant temps above 215°F without knowing it.

On most models, the coolant temp gauge needle wont start moving until coolant temps have reached about 120°F. The gauge needle will continue to rise to the middle of the indication range until coolant temps reach about 185°F. Once at 185°F the gauge needle will remain in the middle of indication range until about 212°F. Once temps go above about 212°F the gauge needle will rise until it hits the red zone, which is about 248°F.

DAM (Dynamic Advance Multiplier)

Expected Values – 04-21 STI, 06-14 WRX, 05-12 Legacy/Outback GT, 04-13 Forester XT 

Expected Values – 02-05 WRX

Expected Values – 15+ WRX, 14-18 Forester XT, 19-22 Ascent

This

The DAM is a Learned Multiplier that is applied to the Dynamic Advance Ignition Tables. The lower this value the is the greater potential the ECU is running less Ignition Advance.

This gauge is based off information received by the ECU from the Knock Sensor. It is one of 3 methods the ECU uses to to adjust Ignition timing to account for non ideal running conditions. The other 2 are Feedback Knock Correction and Fine Knock Learned. The DAM can, in some cases, Adjust Fueling and Disable Boost Control if it drops low enough. The only way to get the DAM back to optimal of 16 or 1 is with an ECU reset or to drive in the load and rpm area that is causing the DAM to drop.

Even more info can be found on our Blog Post.

04-21 STI, 06-14 WRX, 05-12 Legacy/Outback GT, 04-13 Forester XT 

On a stock tune, the DAM will typically be .5 after a ECU reset. The DAM will work its way up to 1.0 if the ECU perceives conditions to do so. It is typical on a Pro Tune to have the DAM start at 1 since the tune has been optimized for all of the performance parts and fuel.

02-05 WRX

On a stock tune, the DAM will typically be 8 after a ECU reset. The DAM will work its way up to 16 if the ECU perceives conditions to do so. It is typical on a Pro Tune to have the DAM start at 16 since the tune has been optimized for all of the performance parts and fuel.

15+ WRX, 14-18 Forester XT, 19-22 Ascent

On a stock tune, the DAM will typically be .6875 EVERY time you start the engine or after a ECU reset. The DAM will work its way up to 1.0 if the ECU perceives conditions to do so. It is typical on a Pro Tune to have the DAM start at 1 since the tune has been optimized for all of the performance parts and fuel.

Feedback Knock Correction (FBK)

Expected Values – 04-21 STI, 02-14 WRX, 05-12 Legacy/Outback GT, 04-13 Forester XT 

 It is normal to see some knock corrections under full throttle, if it is constantly happening, higher than -1.4, and for long periods it might be a good idea to look into it.

Expected Values – 15+ WRX, 14-18 Forester XT, 19-22 Ascent

It is normal to see some knock corrections under full throttle, if it is constantly happening, higher than -2.8, and for long periods it might be a good idea to look into it.

This is the Feedback Knock Correction gauge. This gauge is based off information received by the ECU from the Knock Sensor. If the ECU perceives knock events it can Instantaneously pull ignition timing with Feedback Knock. This is one of 3 methods the ECU uses to control knock. The other 2 are DAM and Fine Knock Learned.

Even more info can be found on our Blog Post.

15-21 WRX

The 2015-2021 WRX use 2 Knock Sensors and the system is very sensitive. So sensitive that even the AC compressor turning on can cause this gauge to be populated.

Fine Knock Learned (FKL)

Expected Values – 04-21 STI, 02-14 WRX, 05-12 Legacy/Outback GT, 04-13 Forester XT 

 It is normal to see some knock corrections under full throttle, if it is constantly happening, higher than -1.4, and for long periods it might be a good idea to look into it.

Expected Values – 15+ WRX, 14-18 Forester XT, 19-22 Ascent

It is normal to see some knock corrections under full throttle, if it is constantly happening, higher than -2.8, and for long periods it might be a good idea to look into it.

This is the Fine Knock Learned gauge. This gauge is based off information received by the ECU from the Knock Sensor. When the ECU detects consistent knock occurrences in specific load and rpm ranges, it can utilize Fine Knock Learned to preemptively retard timing in those areas until knock ceases. This is one of 3 methods the ECU uses to control knock. The other 2 are DAM and Feedback Knock Correction.

The only way to get the Fine Knock Learned to 0 is with an ECU reset or to drive in the load and rpm area that is causing the Fine Knock Learned.

Even more info can be found on our blog post.

Fuel Mode

Expected Values – 2015+ WRX

Homogenous Fuel Mode injects fuel during the intake stroke.

Stratified Fuel Mode injects fuel during the intake and compression strokes.

This is the current Fuel Mode commanded by the ECU. Homogenous Mode would be what most people consider to be normal engine operation. Subaru uses Stratified Fueling on start up and warm up. I believe this is done to improve fuel economy as Stratified Fueling can run much leaner than normal Homogenous Fueling.

When you install a intake or exhaust on your 2015+ WRX you may notice your engine sounds very loud and like its running poorly when you first start it. This is typically caused by Stratified Fueling. A quick way to determine if you are, in fact hearing the Stratified fueling is to monitor this gauge. You should see it change fuel modes right when the car starts running smoothly. It should be on Fuel Mode 2 and then switch to 1 when it starts running smoothly. It does this from the factory and is just not as noticeable when the car is stock. This is not damaging the engine either.

Fuel Pump Duty

Expected Values – 04-21 STI, 02-14 WRX, 05-12 Legacy/Outback GT, 04-13 Forester XT 

Expected Values – 15+ WRX, 14-18 Forester XT, 19-22 Ascent

This is the Fuel Pump Duty ratio commanded by the ECU. When you first start the engine this value will read 100% for up to 30 seconds. These values are adjustable through the ECU so you may see different numbers. The Fuel Pump Duty is dictated by Fuel Injector Duty Cycle. Below a certain Fuel Injector Duty Cycle the ECU will command 33% (Low), above a certain Fuel Injector Duty Cycle the ECU will command 66% (Medium) and above an even higher duty cycle the ECU will command 100% (High). On the 2002-2005 the ECU uses Fuel Injector Pulse Width instead of Fuel Injector Duty Cycle

04-21 STI, 02-14 WRX, 05-12 Legacy/Outback GT, 04-13 Forester XT 

This signal is sent from the ECU to the fuel pump controller. The fuel pump controller uses this signal to determine the desired pulse width modulation of the fuel pump. The controller will change the amount of time the fuel pump is grounded or on/running. 33% means the fuel pump is grounded (on/running) for 33% of a certain time.

100% does not necessarily mean the fuel pump is running at 100% capacity though. The Fuel Pump Controller will receive full battery voltage, but typically only outputs 11.5-12.5v. Fuel pumps typically have the flow rating done at 13.5v. An example is of a Deatschwerks DW65c, it is rated to flow 265lph at 40psi and 13.5v. At 12.5v and 40psi it is rated to flow 226lph. That’s a drop in flow of about 15% flow! This is the reason people hardwire their fuel pumps.

In testing we typically see the following voltages with stock controllers:

Low/33% = 7-8v

Medium/66% = 9-10v

High/100% = 11.5-12.5v

Fuel Rail Pressure

Expected Values – 15+ WRX, 14-18 Forester XT, 19-22 Ascent

This is the Fuel Rail Pressure based off the Fuel Rail Pressure Sensor. This value will vary widely throughout engine operation. Fuel is pumped from the in tank fuel pump (Low Pressure) to the High Pressure Fuel Pump (HPFP) located on the engine. The HPFP is driven by the engines camshaft and will raise the low pressure from 49-58psi to 400-2100+psi.

If you suspect problems with your low pressure fuel pump you can monitor this value. If the psi drops suddenly during a full throttle pull, the low pressure fuel pump may be the cause.

Gear Position Estimated

Expected Values – All Models

This is the current Gear determined by the ECU. The current Gear is estimated from engine speed and vehicle speed. In order for this value to be updated the vehicle must be moving with the engine running and the clutch engaged.

If the transmission gear ratios have been changed these values may be inaccurate unless the tune has been updated to reflect the new gear ratios.

Some ECUs can have per gear tuning for boost and ignition timing so having this value be correct is important.

Ignition Timing

Expected Values – All Models

This is the Total Ignition Timing after all corrections and compensations for cylinder 1. Unless you specifically know what the timing should be this value isn’t very helpful. This value will vary greatly from -20 to 70 degrees BTDC.

Feedback Knock and Fine Knock Learned are much better gauges to monitor.

Injector Duty Cycle

Expected Values – 04-21 STI, 02-14 WRX, 05-12 Legacy/Outback GT, 04-13 Forester XT 

Expected Values – 15+ WRX, 14-18 Forester XT, 19-22 Ascent

This the Injector Duty Cycle (IDC). This is the amount of time, per engine cycle, the ECU is commanding the injectors to be open. This is a calculated number based on Fuel Injector Pulse Width and Engine RPM. As engine RPM increases you have less and less time to inject all the fuel needed for proper combustion. This is one reason you may need larger injectors if you want your engine to rev to a higher redline. At 7000rpm you a have a total time of about 17.1ms to inject all the fuel. At 8000rpm you have about 15ms and 9000rpm you only have 13.33ms to inject all the fuel.

One way to calculate IDC is to multiply Injector Pulse Width by RPM and then divide by 1200. At 7000rpm and a Injector Pulse Width of 15.5ms, your IDC would be 90.42%.

7000 x 15.5 = 108,500

108,500 / 1200 = 90.416

This calculated value can exceed 100%. If it does exceed 100% the fuel injectors may be constantly open. If this happens the injectors never shut off or have any time to cool. This can damage a fuel injector.

2015+ WRX –

Since the FA20 / FA24 engines are direct injected, injecting fuel directly into the cylinder instead of behind the intake valve, you only have about half the time to inject the fuel. You can inject fuel during the intake and the compression stroke. At 7000rpm you only get about 8.5ms to inject all the fuel needed for proper combustion. You will typically only see 30-40% Injector Duty Cycle. This is one of the reasons you see many of the 2015+ WRXs running a E30, E40, or E60 tune. There just isnt enough time to inject the required fuel when running a high ethanol blend.

Intake Air Temperature Manifold

Expected Values – 15+ WRX, 14-18 Forester XT, 19-22 Ascent

This is the Intake Air Temperature from the Intake Air Temperature Sensor in the Intake Manifold. This gauge will read close to ambient temperature when you start the car. While the engine is running, this gauge can read ambient to 130°F+. This gauge can read very high when sitting in traffic on a hot summer day. It is not unheard of to see 150°F+. Once you stat moving the temperature should start to drop.

This temperature is IS after the intercooler. This gauge can give you an idea of how efficient your intercooler is when comparing the Intake Air Temperature (Pre-Turbo) to this value.

2015-2021 WRX

On the stock tune the ECU uses Intake Air Temperature (Pre-Turbo) when applying compensations for Boost, Fueling, or Ignition Timing. Cobb has added the ability to choose between Intake Air Temperature (Pre-Turbo) and the Intake Air Temperature Manifold. To know which sensor your tune is using you can monitor Intake Temp Chosen Source  .

Intake Air Temperature Pre-Turbo

Expected Values – All Models

This is the Intake Air Temperature from the Intake Air Temperature Sensor in the MAF housing (i.e. Pre-Turbo). Every vehicle has this sensor. This gauge will read close to ambient temperature when you start the car. With a good intake system you can see intake temps as close to about 10°F over ambient with the engine running. This gauge can read very high when sitting in traffic on a hot summer day. It is not unheard of to see 150°F+. Once you stat moving the temperature should start to drop.

This temperature is NOT after the intercooler, unless you are running a blow through MAF, so it is not a indication of how well your intercooler is working.

2015-2021 WRX

On the stock tune this is the value the ECU uses when applying compensations for Boost, Fueling, or Ignition Timing. Cobb has added the ability to choose between this sensor and the Intake Air Temperature Manifold. To know which sensor your tune is using you can monitor Intake Temp Chosen Source  .

Intake Air Temperature Chosen Source

Expected Values – 2015-2021 WRX

This is the Intake Air Temperature Chosen Source. This gauge is a Cobb Custom Monitor. This tells you what temperature source the ECU is using for compensations to Fueling, Boost, and Ignition Timing.

Mass Airflow

Expected Values – All Models

Final mass airflow (in grams per second), as determined by the ECU. This value can vary greatly from 1 to 300+ g/s depending on the power of the car.

Roughness Cylinder 1-4

Expected Values – All Models

This is the Roughness Count or Misfire Count per Cylinder as determined by the ECU. It is normal to see these count up 1 or 2 at different engine conditions. A good indicator that the cylinder is actually misfiring is when this is constantly counting up. An example would be if you see a count of 1 and then a while later you see a count of 2 that is likely not a misfire. If you see this counting 1,2,3,4,5,6 and so on constantly that is likely a real misfire and should be looked into.

If you only get Roughness Counts when under full throttle/ in boost it could very likely be a bad/improperly gaped spark plug or a failing coil pack. We see this all the time on the dyno. A quick and easy way to determine this is to swap coil packs or spark plugs from cylinder to cylinder. If the Roughness Counts follow the part than you found the problem.

Possible causes for Cylinder Roughness or Misfires:

• Bad/Failing/Improperly Gaped Spark Plug
• Bad or Failing Coil Pack
• Bad or Failing Fuel Injector
• Low Compression

RPM

Expected Values – All Models

This is your Engine Speed or RPM. This is in crankshaft revolutions per minute (RPM) based on the crankshaft position sensor. This is the same gauge as your tachometer on the dash.

Throttle Position

Expected Values – All Models

This is the Throttle Plate opening percentage based on the throttle position sensor. This value can and will be different than the Accelerator Position. When people talk about WOT or Wide Open Throttle they are referring to this value being 100%

Vehicle Speed

Expected Values – All Models

This is your Vehicle Speed. This value comes from the VSS or Vehicle Speed Sensor. This value will be the same as what is on your dashboard. If you have a wheel/tire setup that is not the same outer diameter as the OEM this value may be incorrect.

On older vehicles like the 2004-2007 STI this value comes from a sensor inside the transmission. On 2008+ vehicles this value comes from the a Tone Ring. The Tone Ring can be located on the Wheel Hub, Axle, or part of the Wheel Bearing.

When doing a transmission swap on the 2002-2007 WRX/STI with a transmission from a 2008+ WRX/STI you need a Vehicle Speed Converter like this made by MAPDCCD.

Wastegate Duty / Wastegate Position Actual

Expected Values – 04-21 STI, 02-21 WRX, 05-12 Legacy/Outback GT, 04-18 Forester XT 

Expected Values – 2022+ WRX,  2019-2022 Ascent

This is the final Wastegate Duty Cycle as commanded by the ECU. This is the duty cycle of the engines Electronic Boost Controller.  This value can vary from 0-90% with 0% causing the vehicle to run wastegate pressure and 90% which try’s to close the wastegate as much as possible. This value can be compensated by Intake Air Temp, Barometric Pressure, Coolant Temp, and Turbo Dynamics. Since this value is compensated by so many factors along with its initial values in the tune monitoring this value can be difficult and not very helpful.

2022+ WRX,  2019-2022 Ascent-

This is the Wastegate Position Actual. Vehicles equipped with the FA24 (2022+ WRX, 2019-2022 Ascent) have a electronic wastegate. They no longer have a electronic boost controller that uses boost pressure to control boost, rather it controls the boost directly with the wastegate itself. This value is also compensated by Intake Air Temp, Barometric Pressure, and Turbo Dynamics. This value can vary widely from 0 mm (Fully Closed) to 15 mm (max open). Since this value is compensated by so many factors along with its initial values in the tune monitoring this value can be difficult and not very helpful.

One interesting note for the 2022+ WRX is you do not need to upgrade the boost controller. Even with some of the aftermarket turbos avaiable you still re use the stock wastegate actuator.