GM > Engine > Fuel Control > Accel Enrich

Acceleration Enrichment
Acceleration enrichment is a simple throttle transient fuel compensation calculation. Using the change in TPS (TPS delta) as the primary factor, the PCM calculates an Enrichment Fraction. The enrichment fraction is then added to the current commanded fuel. Various modifiers exist to control the rate and profile of the fuel delivery with time, also, other modifiers exist based on vehicle speed etc.

AE Qualifiers

• Use Filtered TPS: This switch controls if the VCM uses a filtered TPS delta or an unfiltered value, for the AE calculations.
• TPS Filter Coefficient: Lag filter coefficient for TPS filter (if enabled).
• WOT Disables AE: If checked then WOT/PE mode will disable AE.
• Enable TPS Delta vs. ECT: If the positive change in TPS exceeds this value the AE will be enabled.
• Disable TPS Closing Delta: If the TPS delta is below this value then AE will be disabled.
• Re-Enable TPS %: TPS must drop below this to re-enable AE.
• Disable Refcount Limit: Ref Count Limit to disable AE.

AE Base Value

• AE vs. TPS Max Delta: This is the base Enrichment Fraction vs. the maximum TPS delta seen during this enable period.

AE Modifier

• AE Modifier vs. Baro: Multiplier vs. Barometric Pressure
• AE Modifier vs. Speed: Multiplier vs. Vehicle Speed
• AE Modifier vs. RefCounts: Multiplier vs. Reference Counts. This is the main time profile of the AE enrichment.
• AE Modifier vs. ECT vs. ERT - Gear: Startup (vs. Engine Run Time) AE modifier in Gear
• AE Modifier vs. ECT vs. ERT - P/N: Startup (vs. Engine Run Time) AE modifier in Park or Neutral
• Startup AE Modifier vs. AFR Correction: Startup AE modifier versus the startup AFR correction factor.
• Startup AE Modifier vs. TPS: Additional TPS modifier for startup conditions.

Deceleration Enleanment
Deceleration Enleanment (DE) is the opposite function of AE. DE monitors for negative TPS transients and subtracts fuel accordingly.

DE Qualifiers

• Use Filtered TPS: This switch controls if the VCM uses a filtered TPS delta or an unfiltered value, for the DE calculations.
• TPS Filter Coefficient: Lag filter coefficient for TPS filter (if enabled).
  
• Disable TPS Closing Delta: DE is disabled if the TPS is closing slower than this.
• Enable TPS Delta: DE is enabled if the TPS is closing faster than this.
• Disable Refcount Limit: Ref Count Limit to disable DE.

DE Base Value

• DE vs. TPS Max Delta: This is the base Enleanment Fraction vs. the maximum TPS delta seen during this enable period.

DE Modifier

• DE Modifier vs. ECT vs. Gear: Multiplier vs. Transmission in gear or Park/Neutral.
• DE Modifier vs. RefCounts: Multiplier vs. Reference Counts. This is the main time profile of the DE enleanment.
• DE Modifier vs. Vacuum: Multiplier vs. manifold vacuum.