Spedometer help
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Mountain Pass
Joined: Mar 2006
Posts: 137
Likes: 9
Spedometer help
One little thing after another it seems.
2003 f250 4x4 speedometer not working right today. Stays at 0 until I'm probably doing around 40-45 mph then jumps to 75 and stays there until I slow down (probably to 10 or so) then drops back to 0 and stays there.
VSS or something else?
2003 f250 4x4 speedometer not working right today. Stays at 0 until I'm probably doing around 40-45 mph then jumps to 75 and stays there until I slow down (probably to 10 or so) then drops back to 0 and stays there.
VSS or something else?
Thread Starter
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Mountain Pass
Joined: Mar 2006
Posts: 137
Likes: 9
Drove it this morning. No DTCs, ABS light is not on, OD light is not flashing. Shifted fine and odometer was working. Using forscan I was able to read rear diff speed. Makes me think it isnt a vss problem but I got one anyway. Do the abs sensors also contribute to speedometer function?
Anybody have this issue?
Anybody have this issue?
FTE Leadership Emeritus
Joined: May 2014
Posts: 27,354
Likes: 5,946
From: Lake Hartwell, GA
Hey there!
My first suspect would be the VSS or the circuitry involved. You will need a multimeter as a visual inspection tells you nothing unless there is a broken/frayed wire.
Check this link and the subsequent link for troubleshooting procedures and pinpoint test: https://www.ford-trucks.com/forums/1...l#post20299580
My first suspect would be the VSS or the circuitry involved. You will need a multimeter as a visual inspection tells you nothing unless there is a broken/frayed wire.
Check this link and the subsequent link for troubleshooting procedures and pinpoint test: https://www.ford-trucks.com/forums/1...l#post20299580
Thread Starter
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Mountain Pass
Joined: Mar 2006
Posts: 137
Likes: 9
Hey there!
My first suspect would be the VSS or the circuitry involved. You will need a multimeter as a visual inspection tells you nothing unless there is a broken/frayed wire.
Check this link and the subsequent link for troubleshooting procedures and pinpoint test: https://www.ford-trucks.com/forums/1...l#post20299580
My first suspect would be the VSS or the circuitry involved. You will need a multimeter as a visual inspection tells you nothing unless there is a broken/frayed wire.
Check this link and the subsequent link for troubleshooting procedures and pinpoint test: https://www.ford-trucks.com/forums/1...l#post20299580
When I do the gauge self test, all gauges work but the speedo goes now from over 100, down to 78, then back to over 100.
I recently greased the front right hub through the abs hole when doing brakes so I pulled it and cleaned it off just in case but no change on the dash.
The rear vss had some fuzz on it so I cleaned it off and put it back; was reading speed in forscan either way. I'll have to order one since the parts store doesn't have it but I'm still doubting its a sensor issue at this point.
FTE Leadership Emeritus
Joined: May 2014
Posts: 27,354
Likes: 5,946
From: Lake Hartwell, GA
There may be a fault in the circuit board of the cluster or the ribbon cable may be corroded or have debris on it where it goes into the back of the cluster.
A somewhat common practice to clean the exposed ribbon cable contacts like that is to use a pencil eraser to clean the contacts, then some electrical contact cleaner to rinse them.
If FORScan shows the proper speed of the vehicle, there is an issue between the PCM and the cluster.
I believe there is a speedometer pinpoint test in the Ford Service Manual, but my laptop is not accessible at the moment.
I would like to "phone a friend" and see if @FordTruckNoob is able to help out. I believe it is in the PC/ED volume. I am 75% sure I have seen one...
A somewhat common practice to clean the exposed ribbon cable contacts like that is to use a pencil eraser to clean the contacts, then some electrical contact cleaner to rinse them.
If FORScan shows the proper speed of the vehicle, there is an issue between the PCM and the cluster.
I believe there is a speedometer pinpoint test in the Ford Service Manual, but my laptop is not accessible at the moment.
I would like to "phone a friend" and see if @FordTruckNoob is able to help out. I believe it is in the PC/ED volume. I am 75% sure I have seen one...
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FTE Chapter Leader
Joined: Jan 2005
Posts: 13,122
Likes: 4,725
From: Henderson, NV
I would like to "phone a friend" and see if @FordTruckNoob is able to help out.
Seriously though, the answer is in the diagnostic procedure in the document I have attached.
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Thread Starter
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Mountain Pass
Joined: Mar 2006
Posts: 137
Likes: 9
Thank you. Thats a bit intimidating to me though.
Double checked forscan against a gps speedometer app and they match.
Is there a transmission sensor to check out? now that it is pegged at over 100, when I am in 3rd gear around 35 mph the speedometer drops down to 78 then when I slow to around 25, it goes back to over 100.
FTE Chapter Leader
Joined: Jan 2005
Posts: 13,122
Likes: 4,725
From: Henderson, NV
Thank you. Thats a bit intimidating to me though.
Double checked forscan against a gps speedometer app and they match.
Is there a transmission sensor to check out? now that it is pegged at over 100, when I am in 3rd gear around 35 mph the speedometer drops down to 78 then when I slow to around 25, it goes back to over 100.
Double checked forscan against a gps speedometer app and they match.
Is there a transmission sensor to check out? now that it is pegged at over 100, when I am in 3rd gear around 35 mph the speedometer drops down to 78 then when I slow to around 25, it goes back to over 100.
If FORScan shows the CANbus is communicating the correct speed, the problem is most probably in the cluster.
FTE Leadership Emeritus
Joined: May 2014
Posts: 27,354
Likes: 5,946
From: Lake Hartwell, GA
FTE'r Mark K had a comment recently concerning the VSS on the speedometer in relation to the transmission and the OSS/TSS.
Link: https://www.ford-trucks.com/forums/1...l#post20299529
Link: https://www.ford-trucks.com/forums/1...l#post20299529
Thread Starter
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Mountain Pass
Joined: Mar 2006
Posts: 137
Likes: 9
Just a quick update on this. I haven't had a chance to pull the dash and check for issues in the wiring yet (this is my daily driver again) but I used the diagnostic tool on the odometer yesterday. Speedometer function on the odometer matched what my GPS speedometer was showing. Does the odometer diagnostic tool get its info from somewhere other than what the speedometer gets or is this a pretty clear indication the speedometer gauge has failed?
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