460 Ford Forum banner
1 - 4 of 4 Posts

6 Posts
Discussion Starter · #1 ·
I have a 1989 F250 with a 460 and the TFI module is the remote mount version as seen in this image:

Mine is the grey one. I am very confused because everybody I have asked about this doesn't know or says it'll be fine but doesn't go into depth. The remote mount, if I understand correctly, is mounted remotely. AKA NOT directly on the distributor but instead on the fender. The distributor mounted one, if I understand correctly, IS supposed to be mounted directly on the distributor. The difference between the two, as shown in the image, is the 3 prongs, Hall Effect Ground, Hall Effect Power, and PIP signal, as well as wheather terminal 6 is "PIP in" or "PIP out".

My confusion here is, I have the REMOTE mounted TFI module, but it is mounted directly onto the DISTRIBUTOR. I may be understanding this incorrectly, but it seems pretty straightforward to me. Remote mount is mounted remotely, distributor mount is mounted to distributor. Please let me know if I'm missing anything or if my assumptions are correct.

The distributor that the previous owner installed was installed 1 tooth off, so I could assume he possibly got the wrong TFI module as well. It is just weird to me because the truck ran like this. Doesnt run anymore, having spark issues and had to replace PCM due to injector issues. but it ran decently with this TFI setup..

Thanks in advance!

146 Posts
Well, the remote one is what they went to to stop frying the modules. Heat is normally what causes them to fail and is likely what happened to yours.

The pin out difference might mean you are looking at the wrong alternate version.

Sent from my SM-N950W using Tapatalk

75 Posts
As some of these parts start to get old, they just become an issue. Reman parts are not reliable. It cost money either way. I just converted my '88 to Carb and HEI so that I was in control. I almost went Holley to control the EFI but I wanted cheap and a running truck. I had everything laying around other than an HEI Dizzy and made my own adapter plate.

6 Posts
as i recall there are 4 different modules - 2 grey and two black - a grey and a black for m/t vehicles and a grey and a black for a/t vehicles. i know accel still shows them in inventory..

credits for the following are below. please forgive me if this is too long. i have a page i will have to scan that has more info on choice of grey or black module if i can find it.

Ford Ignition System can be broken down into two main categories: Those that have a distributor, and those that do not. Duraspark, TFI, and TFI IV are examples of Ford Electronic Ignition that use a rotating distributor to fire the spark plugs. DIS, EDIS, IEDIS, and IEDIS with COP are current examples of Ford Ignition Systems that do not use a rotating Distributor to fire the spark plugs.

TFI-IV ignition systems were introduced in 1983 along with the EEC-IV Electronic Engine Control system. The components of the TFI-IV system include:
  • a TFI-IV ignition module (Ignition Control Module - ICM)
  • a distributor
  • a Hall effect PIP sensor within the distributor (Camshaft Position sensor - CMP)
  • an E-core ignition coil
  • spark plugs and secondary circuits
  • an EEC-IV engine control module (Powertrain Control Module - PCM)
Distributor Mount vs. Remote Mount TFI-IV ICM
TFI-IV ignition systems have two distinct configurations. In the first configuration, the TFI-IV ICM is mounted on the distributor and has three pins, which plug into the Hall effect camshaft position sensor (commonly known as the PIP or Profile Ignition Pickup sensor) inside the distributor. This configuration is called a distributor mounted ICM. In the second configuration, the ICM is not mounted on the distributor but in another location within the engine compartment. This configuration is called a remote mount ICM.
The distributor mounted TFI-IV ICM uses a Universal Distributor which has an opening in it through which the pins of the ICM plug into the CMP (PIP) sensor. The remote mount TFI-IV ICM uses a Sealed Distributor. The CMP (hall effect PIP) sensor is located inside the distributor on both configurations. There are no mechanisms on either distributor for either centrifugal or vacuum advance. The CMP sensor inside the distributor responds to a rotating metallic shutter on the distributor and produces a digital PIP signal. The PIP signal is an indication of engine rpm and engine/piston position for both the ICM and the PCM. Because the shutter is mounted on the distributor shaft, two revolutions on the crankshaft are required to fire each spark plug once. The distributor rotates at half the crankshaft speed.

Push Start versus Computer Controlled Dwell TFI-IV ICMs
The internal circuitry of the TFI-IV ICM will have two possible arrangements; push start (PS) or computer controlled dwell (CCD).
The push start system allows for increased dwell (coil on time) when starting the engine. After engine start, the ICM internally determines coil on time (dwell) based on engine rpm (derived from the PIP signal), previous spark position and, coil charge time. The PCM calculates spark timing and outputs a rising edge of SPOUT at the appropriate time. The ICM turns the coil off whenever it sees a rising edge of SPOUT. The SPOUT signal is an acronym for SPark OUTput, a digital signal generated by the PCM. The falling edge of SPOUT is ignored by the ICM. On a push start system, SPOUT only controls when the coil fires. The dwell was designed to provide either 17% or 32% excess dwell to ensure sufficient coil charge time under transient engine-acceleration conditions. Push start TFI-IV ICMs are gray in color.
A computer controlled dwell (CCD) system uses both edges of the SPOUT signal. The PCM calculates spark timing and outputs a rising edge of SPOUT at the appropriate time. The ICM turns the coil off whenever it sees a rising edge of SPOUT. The falling edge of SPOUT is used by the ICM to turn the coil on. The coil on time (dwell), is therefore, entirely controlled by the PCM-generated SPOUT signal. The ICM does not internally determine dwell, it just responds to directly to SPOUT signal it receives. The PCM determined the correct dwell by measuring the time it takes for the coil to reach a predetermined current level. This has the advantage of limiting excess dwell, which significantly reduces heating in the ICM. TFI-IV ICMs that utilize computer-controlled dwell are black in color.
thanx to ELECTRO on fordforums.com for the above.

the following comes from ria2005 on FTE

1993 and earlier trucks use the gray colored Push-Start style Ignition Control Module. There are two different versions.

One is distributor mounted

Motorcraft - DY1074 (supercedes DY425)
Ford - 5U2J-12A297-AA, 5U2Z-12A297-A
Wells - F121
Niehoff - FF409
Standard - LX218
NapaEchlin - TP31
Delphi - DS10051
Transpo - FM425
MSD - 83648 (Made by Transpo above)

The other is a remote mount Push-Start ICM

Motorcraft - DY1075 (supercedes DY533)
Ford - 5U2Z12A297B (supercedes E
Wells - F125
Niehoff - FF411
Standard - LX226
NapaEchlin - TP33
Delphi - DS10053
Transpo - FM533

1994 and later trucks use a remote mount CCD-style ICM

Motorcraft - DY1077 (supercedes DY679, DY667, DY645)
Ford - 5U2Z-12A297-D (supercedes F1PZ-12A297-A)
Wells - F139
Niehoff - FF413
Standard - LX-241
NapaEchlin - TP29
Delphi - DS10056
Transpo - FM544

Ford's documentation for the most part have the part numbers/descriptions reversed for the actual application. The aftermarket copied their info so most have the same issue. The above is correct and has been verified dozens of times.

"If in doubt about which TFI module belongs on a particular vehicle, consult the ignition system-wiring diagram for the vehicle. If the wire going to pin #4 on the EEC-IV computer comes directly from pin #4 of the TFI module, it is a CCD system. If not, it is a Push Start system." it is my understanding this is true...
1 - 4 of 4 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.