Subaru Factory Monitor Descriptions For Accesstuner And V3 Accessport

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May 2024

Introduction

This document provides descriptions of each of the data monitors available to view and log in the current Accesstuner software and V3 Accessport firmware. Not all monitors are available for all vehicles due to differences in vehicle hardware and/or engine control unit (ECU) capabilities. Some monitors are only available in the latest ECU version (strategy) for a given vehicle.

For help with monitors specific to the COBB Custom Features, please see the separate COBB custom monitor guide.

Glossary of Acronyms

• • A/F = Air/Fuel
    
    
  • AT = Automatic Transmission
    
    
  • AVCS = Subaru's Active Valve Control System (i.e. variable valve timing)
    
    
  • CL = Closed Loop fueling
    
    
  • CVT = Continuously Variable Transmission
    
    
  • DAM = Dynamic Advance Multiplier
    
    
  • DIT = Subaru's "Direct Injection Turbo" motor (14-18 FXT, 15+ WRX, 19+ Ascent)
    
    
  • EQ Ratio = Equivalence Ratio
    
    
  • ECU = Engine Control Unit
    
    
  • FXT = Forester XT model
    
    
  • LGT = Legacy GT model
    
    
  • MAF = Mass Airflow
    
    
  • MT = Manual Transmission
    
    
  • OL = Open Loop fueling
    
    
  • RPM = Revolutions Per Minute (referring to engine speed)
    
    
  • TGV = Tumble Generator Valve
    
    
  • TPS = Throttle Position Sensor (or more generically referring to throttle position)
    
    
  • VDC = Vehicle Dynamics Control
    
    
  • VSS = Vehicle Speed Sensor (or more generically referring to vehicle speed)

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Accelerator Voltage SUB (Accel Volts Sub) -> Sub accelerator pedal position sensor output voltage.

AF 1 Trims Total (AF 1 Trims Total) -> Total #1 fuel trims ('AF Correction 1' + 'AF Learning 1').

AF Correction 1 (AF Correction 1) -> Short-term (immediate) fueling correction in closed loop based on input from the front oxygen sensor. This is a percentage correction of the injector pulse width. Positive values indicate fuel is being added as a result of the correction. Negative values indicate fuel is being removed.

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AF Learning 1 (AF Learning 1) -> Long-term (learned) fueling correction based on patterns of 'A/F AF Correction #11' in closed loop, which is based on input from the front oxygen sensor. This is a percentage correction of the injector pulse width. These values are determined and applied based on four separate mass airflow ranges. This value represents the current correction that is being applied. Positive values indicate fuel is being added as a result of the correction. Negative values indicate fuel is being removed.

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AF Learning 1 Range A (AF Learning 1 A) -> Long-term (learned) fueling correction for airflow range 'A' based on patterns of 'A/F AF Correction #11'. This is a percentage correction of the injector pulse width. Positive values indicate fuel is being added as a result of the correction. Negative values indicate fuel is being removed. This value is determined and applied based on the first mass airflow range only. The mass airflow ranges are determined by the axis of the 'A/F Learning #1' table.

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AF Learning 1 Range B (AF Learning 1 B) -> Long-term (learned) fueling correction for airflow range 'B' based on patterns of 'A/F AF Correction #11'. This is a percentage correction of the injector pulse width. Positive values indicate fuel is being added as a result of the correction. Negative values indicate fuel is being removed. This value is determined and applied based on the second mass airflow range only. The mass airflow ranges are determined by the axis of the 'A/F Learning #1' table.

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AF Learning 1 Range C (AF Learning 1 C) -> Long-term (learned) fueling correction for airflow range 'C' based on patterns of 'A/F AF Correction #11'. This is a percentage correction of the injector pulse width. Positive values indicate fuel is being added as a result of the correction. Negative values indicate fuel is being removed. This value is determined and applied based on the third mass airflow range only. The mass airflow ranges are determined by the axis of the 'A/F Learning #1' table.

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AF Learning 1 Range D (AF Learning 1 D) -> Long-term (learned) fueling correction for airflow range 'D' based on patterns of 'A/F AF Correction #11'. This is a percentage correction of the injector pulse width. Positive values indicate fuel is being added as a result of the correction. Negative values indicate fuel is being removed. This value is determined and applied based on the fourth mass airflow range only. The mass airflow ranges are determined by the axis of the 'A/F Learning #1' table.

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AF Learning 3 (AF Learning 3) -> Long-term (learned) fueling correction based on patterns of 'A/F AF Correction #33', which is based on input from the rear oxygen sensor. This is a percentage correction of the injector pulse width. Positive values indicate fuel is being added as a result of the correction. Negative values indicate fuel is being removed.

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Fuel Injector Timing CRANKING TABLE SOI (Inj Timing Crank Table SOI) -> (Beta) This is the table value from the Fuel Injector Start of Injection (Cranking) table.

Fuel Injector Timing Homogeneous EOI (Inj Timing H EOI) -> This is the final table value from the Fuel Injector Start of Injection (Homogeneous) Main table (Beta) End of injection (in crank degrees btdc) calculated from the Start of Injection  (Homogeneous) Main table(s) with comps, RPM, and IPW in homogeneous fuel mode.

Fuel Injector Timing Homogeneous EOI to Ignition (Inj Timing H EOI Ign) -> (Beta) End of injection (EOI) to ignition timing (in crank degrees) calculated from EOI and ignition timing in homogeneous fuel mode.

Fuel Injector Timing Homogeneous EOI to Ignition Time (Inj Timing H EOI Ign Time) -> (Beta) Time of End of injection (EOI) to ignition timing calculated from EOI, ignition timing, and RPM in homogeneous fuel mode.

Fuel Injector Timing Homogeneous SOI (Inj Timing H SOI) -> (Beta) This is the final table value (in crank degrees btdc) from the Fuel Injector Start of Injection (Homogeneous) Main table(s) with compensations applied.

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Gear Speed (Gear Speed) -> This is the rev/mi calculation by the ECU based on RPM and vehicle speed to determine the current estimated gear.

Gear Speed Calculated (Gear Speed Calc) -> This is the rev/mi gear speed calculation from RPM and vehicle speed.

Hot Restart Enrichment (Hot Restart Enr) -> Post-start hot-restart decay enrichment fuel adder (EQ ratio) as determined by the 'Hot-Restart Enrichment...' tables. This value begins decaying after engine start to provide post-start enrichment during hot-restart conditions. Higher values indicate greater enrichment.

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