Ford – Speed Density ECMs


The first EFI ECMs used by Ford were speed-density featuring a MAP sensor and either a manual or hydraulically shifted automatic (C4/C6/AOD/etc) transmission along with electronically controlled ignition advance with a distributor.  They’re commonly found on early fuel injected Ford trucks like F150, 250, 350, Broncos and even early speed-density 5L mustangs/crown vics/etc.

Later models added AOD-E and E4OD electronically shifted transmissions.

The first generation Lightning trucks came with a speed-density 351 and a E4OD transmission.

These ECMs batch-fire injectors.  Swapping to later ECMs typically provides a slight improvement in fuel economy when the replacement ECM uses sequential injection.

As a rule of thumb, software support is very limited for these models.  These may not be the best choice for a beginner or someone without prior tuning experience.  Be warned.

Strategy/BIN Swapping

While support in general is very limited for these models, there are a select few models/applications that are well-supported.  Fortunately, it is sometime possible to “swap strategies” and use a bin file that has software support in an ECM which otherwise lacks direct support.  Unlike MAF ECMs, the specific combinations of engine components factor highly in each particular speed-density calibration.  Use of a well-supported bin/strategy with a different engine than it was originally intended will often require major tuning due to differences in cylinder count, engine displacement, compression, camshaft.

The easiest way you can figure out which strategies will interchange is to match the hardware ID on the label of the ECM.



This is an “EFI-SD48B” ECM.  Any bin/strategy that runs on it (including a first generation lightning C3P1 / LHBL0 / LHBL1 ) will also run on other EFI-SD48B ECMs, and probably EFI-SD48E etc.  I don’t have an exact guide for swapping but if it is very close it’s at least worth a shot.

This document will be published incomplete and added to as I find more information and details.

Supported Hardware-Software Combos

These are known working combinations.  Each of these corresponds with a specific hardware ID or IDs known to interchange.

EFI-SD48B family: speed density, E4OD transmission.  Native to Lightning, F150, F250, F350 approximately 1992-1995

  • Box codes C3P1, C3P2, C3p3 (1st gen Lighning), ICY1, T2X1, many more
  • LHBL0 / LHBL1 strategies work
  • Supported by Core Tuning definitions ( ) LHBL1 strategy
  • Supported by Binary Editor (maybe?) via LHBL1.xlsx definition (BE website)
  • Supported (maybe?) by Decipha’s speed-density definitions for TunerPro RT ( )
  • Decipha suggests that the definitions for TunerPro RT will work for “EFI-SD4x” implying that broad strategy/bin swapping is possible

SFI-SD1 family: 87-88 Mustang 5.0 speed density

Z2D1 / EFI-SD47B / F2TF-12A650-AHB: Supported by EEC Editor def/dlm edit/log via Z2D1 specific.  May also work with other options.


Unsupported/Unknown Hardware-Software Combos


EFI-SD20B – suspect manual / non-electronic automatic transmissions.  Earlier like 90-92 models?  Support unknown.

SFI-SD3 / EA2 1988 Lincoln town car