TMF Idle Speed Control

For Idle Speed Control, users often try to manipulate airflow with the throttle position to maintain engine speed.  This strategy works better with solenoid systems (ICV) because the position vs airflow has more effect on the airflow. 

With DBW (especially larger throttles), small changes to the throttle position have greater effects on airflow (less resolution).  The whole approach for controlling airflow to idle is revisited.    

TMF (Throttle Mass Flow) Idle Speed Control is a special function Emtron leverages that allows superior control for airflow control at idle speed.  

Screenshots 1: Initial Position (g/s)

Initial Position Airflow Example

The concept is the airflow to idle the engine is mapped and controlled.  Initial Position = airflow based on XY parameters in the table in grams per second. 

A PID loop can be enabled like traditional Idle Systems for adaptation.  It has more control because its control output is air flow, not raw position. 

Screenshots 2: Throttle Body Model

Throttle Body Model Setup


Throttle Body Area Table


The air mass is translated to position through the Throttle Body Model which should be validated. 

**Regardless of using throttle body modelling as part of the engine tuning air flow model, TMF Idle Speed Control looks at the TMF calculation to determine the DBW position 

Screenshots 3: TMF Idle and using Idle Ignition Control


Another example of a Base Idle Initial Position (air flow), working on conjunction with ->

Example base Idle Ignition Table. 

TMF Idle Speed Control should be treated as a “base air delivery” system. 

Idle Ignition Control should be relied on to sort out finer idle speed error because of its effect on engine torque at low engine speeds. 

The Emtron Idle Ignition Control is a comprehensive system with many settings (including PID controls).  When used in conjunction with the TMF Idle Speed Control, it will yield OE level results on most all applications – with no standard limitation. 

Idle Target being adjusted live – engine following appropriately.

Emtron Log File validating more data/control of Idle Speed.  Note: Position + Ignition control working together.

Back to blog