E40d/pcm problem
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2nd Gear
Joined: Feb 2024
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E40d/pcm problem
Hey everyone. I've got a 1995 f250 7.3 with the E40d and a php tuner.
Lately my truck have been reving to 2500-3000 before shifting out of first. Feels like it's going straight to third.
After running a code reader I found my pcm is reading 0mph while driving. Speedometer is working fine.
Could my php tuner cause this or are these problems separate issues.
Lately my truck have been reving to 2500-3000 before shifting out of first. Feels like it's going straight to third.
After running a code reader I found my pcm is reading 0mph while driving. Speedometer is working fine.
Could my php tuner cause this or are these problems separate issues.
Butt-Head
Joined: Apr 2004
Posts: 9,453
Likes: 2,936
From: Reed Point, MT
1st to 3rd is USUALLY a broken intermediate one-way clutch (also known as an "intermediate sprag").
This requires a removal and partial transmission teardown to fix should that be the problem.
For reference, it's E4OD (E-FOUR-OH-D not E-FORTY-D). This failure is usually due to full-power or high stress 1-2 shifts.
Another common failure of 2nd gear is fluid leakage between the transmission case and the center support that houses the intermediate clutch. As the case deforms or the center support bolts loosen, the mechanical seal between the case under the valve body and the center support is disturbed causing fluid that would activate the intermediate clutch to simply leak back into to case instead of applying the intermediate clutch piston. There is a Sonnax kit that uses a rubber seal tube to bridge the gap, and I've used many with success in fixing this leak.......but the symptoms usually involve a weak 2nd gear hold and ONLY when the transmission is cold. When hot (and with "thin" fluid) no joy.
A stuck valve in the valve body can do it too, as can a broken accumulator spring in the accumulator body. A lot of things can be wrong here.
This requires a removal and partial transmission teardown to fix should that be the problem.
For reference, it's E4OD (E-FOUR-OH-D not E-FORTY-D). This failure is usually due to full-power or high stress 1-2 shifts.
Another common failure of 2nd gear is fluid leakage between the transmission case and the center support that houses the intermediate clutch. As the case deforms or the center support bolts loosen, the mechanical seal between the case under the valve body and the center support is disturbed causing fluid that would activate the intermediate clutch to simply leak back into to case instead of applying the intermediate clutch piston. There is a Sonnax kit that uses a rubber seal tube to bridge the gap, and I've used many with success in fixing this leak.......but the symptoms usually involve a weak 2nd gear hold and ONLY when the transmission is cold. When hot (and with "thin" fluid) no joy.
A stuck valve in the valve body can do it too, as can a broken accumulator spring in the accumulator body. A lot of things can be wrong here.
Thread Starter
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2nd Gear
Joined: Feb 2024
Posts: 2
Likes: 0
When I bought the truck I knew I'd have to do a rebuild one day. Just thought before spending crazy money on a rebuild I'd get some more perspective.
Is it possible that my pcm not reading speed be a completely separate issue.
Is it possible that my pcm not reading speed be a completely separate issue.
Butt-Head
Joined: Apr 2004
Posts: 9,453
Likes: 2,936
From: Reed Point, MT
You'd get no 3rd, torque converter clutch apply, or 4th. If you're just not getting 2nd gear, it can't be a speed problem.
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F350Scott
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