5R55W - P0775 code

Hi all, I've got a 2003 Explorer that recently has developed a transmission issue on our Christmas vacation. While driving down the highway with the cruise control on the truck downshifted to maintain speed on an uphill climb. At the top of the rise, the truck wouldn't shift back into 5th gear and the overdrive light started flashing. The truck is now unable to shift into 5th gear and on the 1-2 shift it holds first up to approximately 4500 rpm. I took the truck back home and pulled the following codes:

P0732 - Gear 2 Incorrect Ratio
P0735 - Gear 5 Incorrect Ratio
P0775 - Pressure Control Solenoid B

I've done quite a bit of searching on this forum and it looks to me like it's a problem with the solenoid body. I was planning on heading to the dealership tomorrow to pick up a new one and do the repair myself following some of the detailed threads on this site. Please let me know if you think there is anything else I should check.

Thanks!

Welcome to this forum! Those solenoid blocks on the 5R55W seem to fail around 60k miles. How many miles do you have? Glacier991 has a solenoid block for sale.

The truck just turned over 50,000 right about the time of failure.

btw - I researched transmission type and decided this is a 5R55W because it's a V8 4x4 with the trailer tow package. Does that look right?

Is it a 5 speed? If not, maybe it's the 4R70W. Check the Explorer specs section.

Well, it's a 4-speed at the moment, but it used to be a 5-speed!

The specs section lists 5R55W as the only choice for the 2003 model year.

I thought it was the 5R55W, but I just wanted to make sure when you said it was a V8.

Hate to tell you but your trans just broke it's O/D band. It applies in 2nd and 5th gears. There is a small chance that it's just the servo piston but experiance is telling me otherwise.

Do you think it's a combination of the overdrive band, and the valve body since the code refers to the EPC?

P0732**
SSA, SSB, SSC or internal parts .2nd gear ratio error 2nd gear not commanded.
Correct gear ratio not achieved for commanded gear. Shift errors may also be due to other transmission concerns (stuck valves, damaged friction material). Engine rpm could be higher or lower than expected. May flash TCIL. REFER to the Solenoid On/Off Charts. Then Go To Pinpoint Test A.

P0735
SSA, SSB, SSC, SSD or internal parts 5th gear ratio error 5th gear not commanded. Correct gear ratio not achieved for commanded gear. Shift errors may also be due to other transmission concerns (stuck valves, damaged friction material). Engine rpm could be higher or lower than expected. May flash TCIL. REFER to the Solenoid On/Off Chart. Then Go To Pinpoint Test A

P0755*
SSB SSB solenoid circuit failure SSB circuit fails to provide voltage drop across solenoid. Circuit open or shorted or PCM driver failure during on-board diagnostic. No first gear (short) or no third gear (open). Will turn on MIL. Go To Pinpoint Test A.
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Here is something you can try. Back off the locknut on the band adjusters.Then screw in the adjusters. One will not "bottom out" if it is broken.
Next, clear the DTC's and then do KOEO and KOER. P0755 will return if there is a hard fault in that circuit. I'd replace the solenoid assy if in doubt and for sure if you overhaul the trans.

Update - I decided to take it over to the local Ford dealer to let them do a diagnostic on it and see what their thoughts were. They said it is possibly the solenoid and could also be a broken or burned band. After some discussion, they offered to change the solenoid block for $300 (parts and labor) so I gave them the approval. If that doesn't fix it, the next step is to do a teardown to inspect and repair the bands. The $300 seemed like a pretty good price and saves me the hassle of doing it myself (I didn't really want to mess with the whole drain/refill process) so I figure it's worth a shot.

Unfortunately, they can't get back to it until Tuesday but once they do I'll let you know what they find. I'll be keeping my fingers crossed that the solenoid block fixes the problem.

ddelong1 said:

Update - I decided to take it over to the local Ford dealer to let them do a diagnostic on it and see what their thoughts were. They said it is possibly the solenoid and could also be a broken or burned band. After some discussion, they offered to change the solenoid block for $300 (parts and labor) so I gave them the approval. If that doesn't fix it, the next step is to do a teardown to inspect and repair the bands. The $300 seemed like a pretty good price and saves me the hassle of doing it myself (I didn't really want to mess with the whole drain/refill process) so I figure it's worth a shot.

Unfortunately, they can't get back to it until Tuesday but once they do I'll let you know what they find. I'll be keeping my fingers crossed that the solenoid block fixes the problem.

Click to expand...

Parts must be soooo much cheaper down there in the US !!! I'm kinda jealous. Here that solenoid assy is about $350 alone plus diag and labour and ATF. Good luck and let us know what happens.

Update #2 -

I picked up the truck Tuesday afternoon after the repair and it's been fine so far. The paperwork states they replaced the overdrive servo, part number 4W4Z-7D201-LA. The part cost was $20.34 and the labor came to $260 for the diagnostic and repair work. I'm not sure what piece that is exactly, but I feel like I got off pretty cheap so I'm pleased. Hopefully nothing else will come up anytime soon.

They should have replaced both servos while they were working in that area. Did you check to see if they put back the heat shield? Did they replace the solenoid block?

ddelong1 said:

Update #2 -

I picked up the truck Tuesday afternoon after the repair and it's been fine so far. The paperwork states they replaced the overdrive servo, part number 4W4Z-7D201-LA. The part cost was $20.34 and the labor came to $260 for the diagnostic and repair work. I'm not sure what piece that is exactly, but I feel like I got off pretty cheap so I'm pleased. Hopefully nothing else will come up anytime soon.

Click to expand...

Good deal!! I've only seen one servo piston fail in those things. It gives the same symptoms as a broken band.

Can anyone tell me how you change the O/D servo? Or at least check it to see if it's bad?

The servos are hard to get to when they are in the vehicle since the catalytic converter is in front of them. They have a snap ring holding thre covers in place. It's hard to determine if the servos are leaking other than perform an air leak test with a special adapter plate which goes in the area the valve body is connected to. Look at the pictures in the Project Frankentranny thread (I think that might be the thread which I saw them in). They have a pipe tap connection on the servo covers to monitor each servo with a separate gauge.

Ok, how about just changing it out? Is it a big job?

You could do it a couple of different ways. One way is to remove the catalytic converter, snap ring, and servo pistons (watch out for those springs behind the servo). They make a special servo installation tool, but if you don't have one you could also do it with a C clamp Vise Grip which is used for welding. You have to drop the pan to hold the other side. The special tool gets connected to the pan bolts so that would be easier. Another way to get to the servos is to fold back the carpet, and lift up the access panel on the floor. You have to remove the front seats for this. The access panel is really made for a manual transmission, but the vehicle comes with it either way.

Ok, thanks. When you drop the pan, do you have to also drop the valve body to get to the back side of the servo?

Unless I am misunderstand the access cover in the floor board. It sounds like that cat would still be in the way, and the pan would need to be dropped also? I am imagining that this just allows you to reach in from the top instead of crawling underneath.

Thanks again for all you info....

There is a little space between the catalytic converter, and the servos. It might be better to remove the catalytic converter, especially if you have to drop the pan. The valve body doesn't have to be removed to replace the servos.