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The transmission in the 2001 Mazda Millenia S is a LJ4A-EL, Same as the Ford CD4E I'm told.
I just bought the car only to find that there is a problem is with shifting. It had two transmission codes, P0755 Shift Solenoid B Malfunction and P1770 Clutch Solenoid Circuit. I cleared these codes and they never returned and no other codes are read, the Hold indicator is not flashing either. Strange there are no codes.

It shifts and drives normally from 1st to 2nd, has lots of power, it never goes to 3rd or 4th.
Shift solenoids A and B test ok, around 25 ohms.
When 12v is applied to the solenoids a click can be heard coming from inside the transmission.
Using a voltmeter while driving:
Solenoid A has 12v until shift time to 2nd, it goes to 0v, then shift to 2nd.
Solenoid B has 12v until time to shift to 3rd, it goes to 0v, but no shift to 3rd.
So the TCM is asking for 3rd but the transmission is not giving it.

The range sensor test OK too.

The CD4E manual indicates that these symptoms are associated with the shift solenoid B circuit being always on. Since solenoid B tested ok and the TCM is turning it off that would mean something is physically stuck ON inside the valve body.

If something 3rd/4th gear related was failed mechanically inside the transmission and if the solenoid B circuit was not stuck ON, would the transmission at least leave 2nd and try to shift to 3rd and slip or something.

I'm trying to confirm whether the trouble is in the valve body, which I can fix in the car or if the transmission needs to be pulled.
Thanks in advance for your help.  

If the computer is commanding 3rd but the trans stays in 2nd then the problem is probably in the valve body or the solinoid block.  

Thanks for the reply. Now to get it out and figure out what is stuck.
Any tips....
 

I don't think iv'e ever seen a stuck valve in a CD4E valve body. Shift solinoid B shuts off for 3rd gear which means it exhausts. If the computer is shutting down the solinoid and it's stuck and won't exhaust then the trans would stay in 2nd if you were somehow able to go fast enough for the computer to command 4th the trans would actually shift into 1st. I'm betting on a bad solinoid not a stuck valve. While you have it apart i would recommend installing a Transgo Jr shift kit in the valve body. It improves shift quality dramatically and prevents excess line pressure rise which can crack the main drum.  

Thanks for answering again, this thing has me confused. No codes, no CEL, no flashing hold indicator.
I've since been told that the Jatco LJ4A-EL is not the same transmission as the Ford CD4E. Does that change your line of thinking?
I just reconfirmed the TCM is commanding 3rd, shutting off power to solenoid B at the time it should shift to 3rd but stays in 2nd, at the time to downshift back to 2nd, power is reapplied to solenoid B by the TCM.
Solenoid B has 25 ohms and clicks when 12 volts is applied.
Is there something in the solenoid that could cause it to test ok but not operate the valve body correctly?
In town, 1st and 2nd are perfect, when driving on the highway the engine revs 5000 rpm to get 100km/hr, definitely not 3rd or 4th...lol.  

Thats right your trans is not like a CD4E it is a variation of the RE4FO4A Maxima trans. Thats a different story. In that trans valves get stuck all the time. In fact if you find a lot of metal when you drop the pan you might be wasting your time trying to fix it without an overhaul. Usually valves only stick when something is coming apart and creating fine metal. Drop the pan and see whats on the magnets and then make a decision. How many miles on this trans? What does the fluid look like?  

151,000kms or 94,000 miles, fluid looks clean, doesn't smell burnt. I just bought the car so don't know the history. I kick myself for not test driving on the highway before buying.  

So, lets say the valve body and solenoids were ok and 3rd gear was burned up. Would you expect the transmission to make an attempt to go to 3rd and slip or act like neutral?  

If the solinoids and valves were functioning properly but there was a loss of pressure to the clutch pack it would not stay in 2nd it would shift to 3rd and slip or act like neutral.. 2nd gear is the forward clutch and the band. To achieve 3rd the band has to come off and the direct clutch comes on. If you are staying in 2nd then the band is not coming off.  

Thanks again 440t4 for the help.
Strange there is no:
P0733 Gear 3 Incorrect ratio code.  

It would probably be a good idea to drive the car with a good scanner hooked up in data mode to make sure the computer is commanding 3rd and watch all sensor data.  

Will do...thanks