e40d shifting and speedometer problem
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e40d shifting and speedometer problem
Here's a brain teaser from heck:
I have a 1991, f250, Xlt Lariat, 4x4.
The speedometer bounces around, and gives false low reading. The tranny "bangs" into 2nd, unless I back off the acceleration. It slips into, and out of, 3rd (in an narrow rpm range), smooth shift into 4th. No tranny codes. No engine codes. New RABS and speed control sensors, new dash cluster, new throttle position sensor - and no change. It is slowly getting worse.
ABS computer? If lever positioning sensor or transmission range sensor, why the speedometer problem? What is a RABS proportioning valve and what, if anything, might that have to do with it?
Do I need the Einstein of mechanics or just a good priest?
I have a 1991, f250, Xlt Lariat, 4x4.
The speedometer bounces around, and gives false low reading. The tranny "bangs" into 2nd, unless I back off the acceleration. It slips into, and out of, 3rd (in an narrow rpm range), smooth shift into 4th. No tranny codes. No engine codes. New RABS and speed control sensors, new dash cluster, new throttle position sensor - and no change. It is slowly getting worse.
ABS computer? If lever positioning sensor or transmission range sensor, why the speedometer problem? What is a RABS proportioning valve and what, if anything, might that have to do with it?
Do I need the Einstein of mechanics or just a good priest?
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I dont know whats up, but if you need a new tranny, I have one that was rebuilt last summer(about 3500 miles) and my engine just lost a valve, I bought another truck today, and am planning to part out my diesel. It is a 91 f-250 4x4 diesel. Im am near portland oregon.
lars
lars
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Call me a glutton for punishement, but I still think it is an electronic problem. Besides, the tranny is reputed to be relatively new. This fact only serves to fill me with an even greater fear and loathing.
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From: PA
That is a tough one, and it seems the signs are in fact pointing toward the speed sensor input. Check the wiring and the connections thoroughly, and check your voltage and good grounds (make sure no corrosion) low voltage will cause funny things...
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had a problem with my speed sensor and speedo also, I had the abs computer completely over ridden so now i odnt have abs breaks, but it shifts beautifully, better then when i bought it. I also put in a new speed sensor.
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You might be right. I saw nothing in the 'Haynes Manual' (which begs the question: Is there better than miserable piece of work?) having to do with voltage of the speed sensor. Continuity of circuits, much less finding them, is just outside my range of experience and patience. I did manage to back-probe the TPS which checked out.
My tranny man, suggested the Powertrain Control Module (PCM) may have gone south. But wouldn't that show EEC codes? Speaking of Haynes again, where is the PCM? I think it's behind the dash, to the left of the radio. A real nightmare to pull?
My tranny man, suggested the Powertrain Control Module (PCM) may have gone south. But wouldn't that show EEC codes? Speaking of Haynes again, where is the PCM? I think it's behind the dash, to the left of the radio. A real nightmare to pull?
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From: Colorado
While trying to trace a short in my 92 f150 xlt, I pulled out fuse #8 and got the same transmission symptoms as you and no speedo readout. Might be a long shot but could you have a #8 fuse that is loose?
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Search for PSOM, not sure it applies to your truck.
I think it is PSOM, first I thought it was VSOD. Anyway, on some of these trucks the computer gets a signal from the speedometer cluster and a malfunction causes all kinds of problems.
Once again, if you can figure out what I am talking about, I am not sure if it applies to your truck.
That should be clear as mud, just trying to help.
I think it is PSOM, first I thought it was VSOD. Anyway, on some of these trucks the computer gets a signal from the speedometer cluster and a malfunction causes all kinds of problems.
Once again, if you can figure out what I am talking about, I am not sure if it applies to your truck.
That should be clear as mud, just trying to help.
Last edited by HardScrabble; Aug 15, 2004 at 11:14 PM.