Notices
1987 - 1996 F150 & Larger F-Series Trucks 1987 - 1996 Ford F-150, F-250, F-350 and larger pickups - including the 1997 heavy-duty F250/F350+ trucks

E40D Code 634

Thread Tools
 
Search this Thread
 
Old Mar 28, 2016 | 06:28 PM
  #1  
alf15092's Avatar
alf15092
Thread Starter
|
Freshman User
Joined: Mar 2015
Posts: 36
Likes: 0
From: Huntsville, AL
E40D Code 634

So back last April I started having intermittent hard shifts. I ran the code myself and 634 came up (MLPS voltage higher or lower than expected). The shop I took it to ignored that and ended up replacing the solenoid pack, which solved the problem until this past June. It shifted hard up until November, then it was fine until now when the temperature outside is warming up, it is always fine in cold weather. I ran the the codes today and the same 634 came up. Can this be the cause for hard shifting? why would the temperature outside matter? This is a 1992 F150 302 with 185K miles 4x2 supercab. It runs great otherwise, so I would love to get this figured out. Thanks!
 
Reply
Old Mar 28, 2016 | 06:47 PM
  #2  
Lead Head's Avatar
Lead Head
Lead Driver
15 Year Member
Photogenic
Joined: Jul 2007
Posts: 7,868
Likes: 9
From: Rhode Island
Yes it could most certainly cause hard shifting. Sound like the shop just wanted to cost you money if they ignored the MLPS code. The MLPS is relatively cheap, and pretty easy to change. You don't even need to open the transmission up.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
blue924.9
1987 - 1996 F150 & Larger F-Series Trucks
2
Oct 7, 2014 04:22 PM
triskadek
Escape & Escape Hybrid
5
Mar 8, 2010 03:49 PM
frnkln2003
6.0L Power Stroke Diesel
3
Feb 10, 2008 08:43 AM
cool guy
2004 - 2008 F150
2
Aug 5, 2006 12:02 AM
stevieray
1987 - 1996 F150 & Larger F-Series Trucks
6
Feb 18, 2002 11:45 AM




All times are GMT -5. The time now is 06:53 AM.

story-0
Top 10 Fords at 2026 Carlisle Ford Nationals

Slideshow: Top 10 Fords at 2026 Ford Nationals

By Joe Kucinski | 2026-06-09 11:10:08


VIEW MORE
story-1
3 Best / 3 Worst Parts of Modern Ford Ownership

Based on years of owning multiple modern Ford products.

By Brett Foote | 2026-06-09 10:53:36


VIEW MORE
story-2
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

SPONSORED: From muddy boots to rain-soaked cargo, these upgrades address some of the most common frustrations Ford truck owners face every day.

By Pouria Savadkouei | 2026-06-08 18:50:34


VIEW MORE
story-3
Every 2026 Ford Engine Explained

Here's everything you need to know about every Ford engine available for the 2026 model year.

By Brett Foote | 2026-06-05 12:58:01


VIEW MORE
story-4
10 Ugly Ford Trucks That We Still Kinda Love

Slideshow: 10 ugly Ford trucks that we still kinda love.

By Joe Kucinski | 2026-06-03 09:51:16


VIEW MORE
story-5
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-03 15:43:58


VIEW MORE
story-6
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-06-03 11:38:36


VIEW MORE
story-7
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Slideshow: 10 most expensive Ford trucks ever sold on Bring a Trailer.

By Joe Kucinski | 2026-05-27 16:24:34


VIEW MORE
story-8
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Here's everything that has changed for the latest model year.

By Brett Foote | 2026-05-27 16:17:28


VIEW MORE
story-9
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE