TripMinder Message Center Install!

[arco777]

So for connecting to pin 34 I needed a connector. I scanned the pinout of the PCM harness and noticed 2 unnecessary outputs.

Pin 49 is listed as Not Used. It has a gray/red wire coming from mine going somewhere though so I figured I'd leave it in. What's weird is Gray/Red is also used on pin 46 nearby, Sensor Signal Return.

Pin 54 is A/C WOT cutoff relay (pink/yellow). The Explorer I'm working on does not have AC from the factory, so I guess the wire from there is going to an empty spot in the fuse box. I snipped the wire and re-located the connector to pin 34 to use for the TripMinder.

Also for reference, attached is the connector's pinout - should help anyone attempting this mod. Keep in mind that this is the view of the connector so it's reversed if you're looking at the PCM.

 

[arco777]

Just went for a test drive.

Seems that VSS input is compatible and is pretty close to the stock mechanical odometer reading - 3.8 miles on the TM, 3.9 on the speedometer.

However, despite tapping pin 34 for the fuel flow data, it still shows 0.0 gallons used after the drive.

So I guess on a 94 model UMP1 PCM, there's a signal of some sort (voltmeter reads around 12.5v) on pin 34, but it's not what the TripMinder wants.

 

[NICE59FORDF100]

guys...this is a dumb suggestion...but try hooking it into pin 31 on the 94 pcms...i have a hunch about something, and wanna see if it the instant MPG will work on 31 instead of 34...

 

[arco777]

I just hooked up my TripMinder's fuel flow input to pin 31 and drove around for a few minutes. No change from when using pin 34, sorry. Unless I am truly averaging 200+ miles per gallon.

 

[Joe Dirt]

Actually Arco, you just figured out the secret pin-in from Ford. All the while people have been messing with roof racks, inflating tires, and cleaning MAF's, Ford was just waiting for someone to discover the "Pin 31 Crack" which has now reprogrammed your computer to "epic fuel saver mode" and has given you, indeed, 200 MPG.

Congrats!

 

[arco777]

Actually Arco, you just figured out the secret pin-in from Ford. All the while people have been messing with roof racks, inflating tires, and cleaning MAF's, Ford was just waiting for someone to discover the "Pin 31 Crack" which has now reprogrammed your computer to "epic fuel saver mode" and has given you, indeed, 200 MPG.

Congrats!

Nice one! Thanks for a good laugh!

 

[NICE59FORDF100]

I'm researching, as i type, some ford-only documents and trying to track this down.

 

[IAmTodd]

Might give this a shot if the MPGs can be figured out. As I have a '94 I imagine I'm affected by the high mpgs. Until then I'm relocating my 4x4 buttons to the OHC because it's damn cool!

 

[arco777]

Also posted in Digital Dash Swap -

So maybe you guys know this already but I was wondering what the actual signal was. I don't have the oscilloscope that would make this easier to simply look at pins for, but here it is:

The Data Output Link (DOL) provides a communication line between the EEC and
the vehicle dashboard computer, Tripminder, for the transfer of fuel
consumption information. The fuel flow information sent by the EEC is used
for computation of instantaneous and average fuel economy, which is then
displayed to the driver.
The Tripminder requires an appropriate integer number of pulses within 100
msec period. Therefore, within each background loop or each 100 msec period,
whichever is shorter, the EEC sums the fuel flow and through the injectors
output since the summing period started, converts this sum into DOL pulses,
and outputs these pulses at a maximum frequency of 500 Hz during the
following summation period.
The fuel flow is converted into DOL pulses according to the following
equation:
DOL_COUNT = INTEGER (FUEL_SUM * 7804.19 * INJOUT) + DOL_COUNT
The FUEL_SUM is then reduced by the amount converted into DOL_COUNTS (One
DOL_COUNT = 1.282E-4 lbm).
where,
DOL_COUNT = Number of pulses to be output beginning
in the next summation period. One
DOL_COUNT = 1.282E-4 lbm.
FUEL_SUM = Sum of fuel flow per injector, which was
initiated since last summation period. It is
updated during the Fuel PW output routine.
7804.19 = (48000 pulses/gal)/6.15 lbm/gal, pulses/lmb.
INJOUT = Number of injectors per output port.
(See Fuel Strategy)
14-2 DATA OUTPUT LINK - GXK0
PEDD-PTOPE, FoMoCo, PROPRIETARY & CONFIDENTIAL
FUEL_SUM = FUEL_SUM + LBMF_INJn
LBMF_INJn = Fuel Flow per injector, calculated from
FUELFLOWn (n= 1, 2). (See Fuel Strategy).
---- ---- ---- ---- ---- ----
| | | | | | | | | | | |
| | | | | | | | | | | |
FUELPW ----- ----- ----- ----- ----- ------
|<-- 1 BACKGROUND LOOP -->|----
|| |
|| |
DOL | |
OUTPUT --------------------------- ------------------------

 

[mr cribb]

Ford was just waiting for someone to discover the "Pin 31 Crack" which has now reprogrammed your computer to "epic fuel saver mode" and has given you, indeed, 200 MPG.

Congrats!

Our carbon footprint sucks? I think not @ 200mpg's..... eat your heart out prius owners!!!

 

[LiKuiD]

Glad to see this thread is still alive!

Looks like the 94 PCM's get no love...i'll be keeping an eye on the thread to see if anyone has any progress but after trying every pin I could get my hands on with too much time on this I settle for having a nice in dash clock/VSS sensor.

If I can help at all, let me know!

 

[LiKuiD]

i think the 94's are just affected with this. my guess is that you get a 93 pcm and throw it in and see if it works?

Ya know i've been trying to get my hands on one for over a year now and it's pretty hard out here in NJ where prices from yards are in the $200 range...yeah you heard right

 

[mr cribb]

Ya know i've been trying to get my hands on one for over a year now and it's pretty hard out here in NJ where prices from yards are in the $200 range...yeah you heard right

Why not have some of the rest of us look for you in other states?

I'm not sure what it will cost here, but I can check for you, there's always a gen1 X out there if not several.

 

[IAmTodd]

i think the 94's are just affected with this. my guess is that you get a 93 pcm and throw it in and see if it works?

I thought the 93s were all non-EGR? Would you be able to put a 93 w/o EGR in a 94 w/EGR?

 

[Naasau]

You just need the comp from the kick panel? I have two spares for a 93 auto, want one?

 

[zavaral]

I'm interested on this to see if it will ever get worked out. Maybe one day ill install one on my 91 when I decide to move my light switches from the 4x4 selector position.

 

[arco777]

I thought the 93s were all non-EGR? Would you be able to put a 93 w/o EGR in a 94 w/EGR?

Late 93 had EGR. There were other differences too. I believe they started using CMP sensors in late 93. It would be important to have the right PCM.

 

[LiKuiD]

Why not have some of the rest of us look for you in other states?

I'm not sure what it will cost here, but I can check for you, there's always a gen1 X out there if not several.

Thanks I appreciate it! I've reached out to a bunch of people last year but all I could come up with were RIM0 catch codes which seems to be pretty common on the 94's.

zavaral - If you have a 91 it will work fine, Russ confirmed on his 92 that it works with no problems. The issue seems to be 94 only w/ pin 34.

Naasau - sure! I haven't done any research on the side effects of putting a different ECU in based on the same model...any thoughts what could happen? (Even if its for testing w/out even driving)

 

[Naasau]

Well, last year I had some issues with a comp error that I thought was being caused somewhere by the computer, or primary harness... so I started swapping parts, turned out later that what was going on was an intermittent SPOUT circuit ground causing the engine to go into limp home mode, and the ground was actually a worn wire way up by the tachometer. Seems that the gauge reads a very important signal... I guess that my point is that having had several different pcm's and cpu's didn't actually affect anything, good or bad.

Since then I swapped back in my own 1993 auto, and then later removed it in favor of a manual comp from a 1992 last week. Still no ill effects, though having the M5OD does make my gearing issue more prominent. (I have 33's and 3.73's)

I would send you the original unit from the 93, as it's my favorite, and I just don't see myself going back to an automatic transmission, ever.

 

[willindsay]

Just picked up one of these a week ago for 5$ from Pull-A-Part.

Any news on the issues with 94's?

And does anyone know if switching to a 93 computer would hurt anything?