Ranger speed sensor adj.

I've tried to make this coherant and well thought out...let's see how I did:
1994 Ranger XLT Super 2WD 4.0 V6. Lifted 2 inches. A4LD Automatic
Transmission. Babied all it's life and pretty much good/better than new @ 186,000 miles. Came from the factory with 225/70-R14 tires. Now has P265/75-15's. Using a GPS unit and timing between mile markers verifies a 17.5% difference in indicated vs real speed ie; indicated 40MPH = real speed of 47MPH, etc.
My '94 uses PSOM (Programmable Speedometer/Odometer Module). This gets its info from the RABS speed sensor on the rear differential housing and sends that info on to the Powertrain Control Module and Speed Control Module. Two units that must have correct information.
My questions involve the Programmable portion of the PSOM. How do I do that? I have a program that takes the time between mile markers and the indicated speed and gives the % of difference then explains how to recalibrate the PSOM. I quote, "Hold the RESET button while turning the key on. Then release the RESET button. Press the RESET button again and release to see the calibration constant followed by the word CAL, ie 918CAL. Enter this calibration constant, ie 918."
What RESET button? Enter the calibration constant how? Is this done by using a piece of equipment I can purchase? Is it something that's already on the vehicle (I doubt that)? Does a Ford dealer/Speedometer shop have to do this? When done, this change should get the PCM and SCM info corrected but will this also get the speedometer reading accurate? From what I read in the Factory service manual it should do that as well.
FWIW, I performed all the on-board diagnostic procedures and it was clean, no recorded DTC's.
Thanks, Jay
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. . . TOP POST
the mileage reset button! (trip gauge)
Reseting Recalibrating your PSOM for the Correct Speed Address:http://www.broncodata.com/tech/speedcor.htm
simmer down now....... ever tings gonna be okay......
MarshMonster ~look mah....no tools~ ======== ======== jgibson1 AT COM CAST . NOT (Jay)
I've tried to make this coherant and well thought out...let's see how I did: 1994 Ranger XLT Super 2WD 4.0 V6. Lifted 2 inches. A4LD Automatic Transmission. Babied all it's life and pretty much good/better than new @ 186,000 miles. Came from the factory with 225/70-R14 tires. Now has P265/75-15's. Using a GPS unit and timing between mile markers verifies a 17.5% difference in indicated vs real speed ie; indicated 40MPH = real speed of 47MPH, etc. My '94 uses PSOM (Programmable Speedometer/Odometer Module). This gets its info from the RABS speed sensor on the rear differential housing and sends that info on to the Powertrain Control Module and Speed Control Module. Two units that must have correct information. My questions involve the Programmable portion of the PSOM.
How do I do that?
I have a program that takes the time between mile markers and the indicated speed and gives the % of difference then explains how to recalibrate the PSOM. I quote, "Hold the RESET button while turning the key on. Then release the RESET button. Press the RESET button again and release to see the calibration constant followed by the word CAL, ie 918CAL. Enter this calibration constant, ie 918."
What RESET button?
Enter the calibration constant how?
Is this done by using a piece of equipment I can purchase?
Is it something that's already on the vehicle (I doubt that)?
Does a Ford dealer/Speedometer shop have to do this?
When done, this change should get the PCM and SCM info corrected but will this also get the speedometer reading accurate?
From what I read in the Factory service manual it should do that as well. FWIW, I performed all the on-board diagnostic procedures and it was clean, no recorded DTC's.
Thanks, Jay ======== ========
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Thanks for the link to that site but, try as I might, my analog/mechanical two-stage odometer/trip meter just sits there giving me funny looks as I tell it, "C'mon odometer, say CAL, show me a conversion constant, start flashing, anything....?". I even threatened to replace it with one of those new fangled digital push button type instruments. Nuthin'.
Any other ideas folks?
Jay

speed
key
918CAL.
to
clean,
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. . ========= =========
========== ==========
(trip gauge)
Reseting Recalibrating your PSOM for the Correct Speed Address:http://www.broncodata.com/tech/speedcor.htm
simmer down now....... ever tings gonna be okay......
MarshMonster ~look mah....no tools~ ======== ======== jgibson1 AT COM CAST . NOT (Jay) wrote
Thanks for the link to that site but, try as I might, my analog/mechanical two-stage odometer/trip meter just sits there giving me funny looks as I tell it, "C'mon odometer, say CAL, show me a conversion constant, start flashing, anything....?".
I even threatened to replace it with one of those new fangled digital push button type instruments. Nuthin'.
Any other ideas folks? Jay =========== =========== Jay, I'd have to look it up to be able to tell you which models....
BUT... some of them can only be reprogramed 3 times..and then you have to replace the module.
Like I said, i'm not sure which models. But I think it was pre-1995 models.
Hope that's not yer prob.
MarshMonster ~:~ ========== ==========
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wrote in message (trip gauge)
Reseting Recalibrating your PSOM for the Correct Speed Address:http://www.broncodata.com/tech/speedcor.htm
simmer down now....... ever tings gonna be okay......
MarshMonster ~look mah....no tools~ ============== jgibson1 AT COM CAST . NOT (Jay) wrote
Thanks for the link to that site but, try as I might, my analog/mechanical two-stage odometer/trip meter just sits there giving me funny looks as I tell it, "C'mon odometer, say CAL, show me a conversion constant, start flashing, anything....?".
I even threatened to replace it with one of those new fangled digital push button type instruments. Nuthin'.
Any other ideas folks? Jay ====================Jay, I'd have to look it up to be able to tell you which models....
BUT... some of them can only be reprogramed 3 times..and then you have to replace the module.
Like I said, i'm not sure which models. But I think it was pre-1995 models.
Hope that's not yer prob.
MarshMonster ~:~ ==================
MM
I'm the original owner so, no, too many reprogrammings isn't the problem. It's never been reprogrammed. The problem is the instructions on the bronco site are for electronic, digital display odometers. I don't have that. I have a mechanical odometer set inside the bottom of the speedometer face and a mechanical re-settable trip-meter inside the top of the speedometer face. The numbers go round and round.
So how does one go about reprogamming the PSOM with a mechanical trip-meter?
Jay
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. . ======= ======= Group: alt.trucks.ford Date: Tue, Aug 3, 2004, 11:44pm (CDT+1) From: jgibson1 AT COM CAST . NOT (Jay)
I'm the original owner so, no, too many reprogrammings isn't the problem. It's never been reprogrammed. The problem is the instructions on the bronco site are for electronic, digital display odometers. I don't have that.
I have a mechanical odometer set inside the bottom of the speedometer face
and a mechanical re-settable trip-meter inside the top of the speedometer face.
The numbers go round and round.
So how does one go about reprogamming the PSOM with a mechanical trip-meter?
Jay =========== ===========
ANSWER:
One cannot reprogram the PSOM on a vehical with a mechanical speedo and mechanical trip meter.
sorry
~:~ MarshMonster ~eagerly awaits yer next question~ ========== ==========
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. . ============Group: alt.trucks.ford Date: Tue, Aug 3, 2004, 11:44pm (CDT+1) From: jgibson1 AT COM CAST . NOT (Jay)
I'm the original owner so, no, too many reprogrammings isn't the problem. It's never been reprogrammed. The problem is the instructions on the bronco site are for electronic, digital display odometers. I don't have that.
I have a mechanical odometer set inside the bottom of the speedometer face
and a mechanical re-settable trip-meter inside the top of the speedometer face.
The numbers go round and round.
So how does one go about reprogamming the PSOM with a mechanical trip-meter?
Jay ==================== ANSWER:
One cannot reprogram the PSOM on a vehical with a mechanical speedo and mechanical trip meter.
sorry
~:~ MarshMonster ~eagerly awaits yer next question~ ================== Sorry, but I have no more questions on this topic. Tomorrow I will be taking my truck to a speedometer shop that specializes in this sort of thing. I'm just going to switch out the speedo drive gear and he's got a unit that will feed the corrected info to the engine management system.
Thank you for your help, Jay
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. . ======== ======== Group: alt.trucks.ford Date: Wed, Aug 4, 2004, 4:34am (CDT+1) From: jgibson1 AT COM CAST . NOT (Jay)
Sorry, but I have no more questions on this topic.
Tomorrow I will be taking my truck to a speedometer shop that specializes in this sort of thing.
I'm just going to switch out the speedo drive gear and he's got a unit that will feed the corrected info to the engine management system.
Thank you for your help, Jay ============ ============ Jay, yer welcome.
I know you don't have any more questions on the subject....
however....I am curious about something.
Why does he have to feed corrected info to the engine management system?
~:~ MarshMonster ~stirs his drink~ ============ ============
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