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not your normal speedometer problem


hschwartz3

Member
Joined
Sep 19, 2010
Messages
10
City
Ohio, Amanda
Vehicle Year
2001
Transmission
Manual
the truck: 01 ranger 2wd 5-speed 2.5 4 cyl. standard cab 7.5 axle

the problem: speedometer works up until 73-74 mph then falls to zero. I dont go over 74 often, but sometimes i do depending on the highway. This is my service vehicle, so when the speedo stops so does the odometer and so does the mileage reimbursement.

I've replaced the VSS sensor on top of the rear axle diff, but it didnt change anything. Any other ideas? thanks for the help.
 
There might be another sensor right on top of the output to the driveline on the back of the transfercase. At least there is one there on my 4x4 1996. That sensor could be bad too.

The one on the top of the diff is solely for ABS up until like 1998 when the switched to pure digital readings for the speedo from my understandings.
 
There might be another sensor right on top of the output to the driveline on the back of the transfercase. At least there is one there on my 4x4 1996. That sensor could be bad too.

The one on the top of the diff is solely for ABS up until like 1998 when the switched to pure digital readings for the speedo from my understandings.

I thought they switched in '94-'95.
 
I think there is a grey area.

From the article it says that up until 1995 was gear driven cable from the tranny/transfercase up to the speedo.

Then it says 1998 onward is purely digital from the ABS sensor off the Diff.

Then there is my truck which is neither. 1996 and it has a "gear driven sensor" on the output shaft the transfercase by the driveline. Which sends a digital signal up somewhere to the computer or something...
 
The fulsizes switched much earlier. My '92 and '95 are digital with a single speed sensor on the top of the diff.
 
yeah, there is no sensor on the tailhousing of the transmission.

From my understanding, the PCM converts the raw data from the VSS sensor on the rear diff to calculate vehicle speed.

I'm not sure where to go from here, didn't know if any other members had a similar issue.
 
I'd bet its the psom (programable speedometer and odometer module) when they fail they get bouncy like mine or they work within some oddball range, outside of that they drop, which is what you are experiencing.
 
^^ so since my trucks speed bounces to 100 sometimes then back to the right speed or back to 0 then back to the right speed its that module?


where is it located how much do it cost to replace im so tired of my speedo being off.


it was right even after i changed my tire size i changed my speedo gear and what not to make it right and it was dead on for a while now it runs a little fast
 
^^ so since my trucks speed bounces to 100 sometimes then back to the right speed or back to 0 then back to the right speed its that module?


where is it located how much do it cost to replace im so tired of my speedo being off.


it was right even after i changed my tire size i changed my speedo gear and what not to make it right and it was dead on for a while now it runs a little fast

Your truck (if its the 94) won't have this modual. It will have a gear in the back of the transmission or t case that you change to adjust the spedometer.Perhaps its not in quite right or have you pulled the dash out recently? I know on my 84 I pulled the dash out for something and when i plugged the cable back in it did what your describing until I pulled it out and fixed it.
 
In his first post he said its an '01. The psom is the speedometer & odometer. Gotta open up the dash to get at it. Before replacing it, check all the wiring from the sensor up to the module.
 
Your truck (if its the 94) won't have this modual. It will have a gear in the back of the transmission or t case that you change to adjust the spedometer.Perhaps its not in quite right or have you pulled the dash out recently? I know on my 84 I pulled the dash out for something and when i plugged the cable back in it did what your describing until I pulled it out and fixed it.

ok thanks man i havent checked the connections and stuff for a while and no i havent even had the cluster out of the truck.

thank again
 
OK, thanks for the replies. I'll check out the wiring harness and stop by the pick and pull yard to get a spare speedo/odometer. Could i possibly use an instrument cluster from an explorer?
 
Pull your dash apart, look at it, get numbers off it, whatever, to match what you find in the JY. Then you'll know which tools to take, how to access it, etc. before you get there. I'd guess 99 and up Explorers, but have no idea about the newer years.

http://www.explorerforum.com/forums/showthread.php?t=218636 is kind of helpful....


Oh yeah, Welcome to The Ranger Station (oops, low post count threw me!).
 
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