2003 transmission trouble upshifting

Joined
May 25, 2021
Thunderbird Year
2003
The trans works perfect in Reverse and Automatic. It downshifts perfect in Standard. It works going 1st to 2nd but only occasionally shifts from 2nd to 3rd, 3rd to 4th, and 4th to 5th
 

biddle

Forum Moderator
Staff member
Joined
Mar 9, 2003
The trans works perfect in Reverse and Automatic. It downshifts perfect in Standard. It works going 1st to 2nd but only occasionally shifts from 2nd to 3rd, 3rd to 4th, and 4th to 5th
Are you having a problem with the select shift? I don't completely understand your issue.
 
Joined
May 25, 2021
Thunderbird Year
2003
Hey Biddle. Happy Thanksgiving from Hawaii. Yes I think what I'm calling the Standard transmission, you're calling the select shift. Sorry I wasn't clear.
I'm amazed by your prompt response....do you know what's wrong?
 

biddle

Forum Moderator
Staff member
Joined
Mar 9, 2003
Hey Biddle. Happy Thanksgiving from Hawaii. Yes I think what I'm calling the Standard transmission, you're calling the select shift. Sorry I wasn't clear.
I'm amazed by your prompt response....do you know what's wrong?
My late grandparents lived on Oahu for 12 years when my grandfather was relocated there for his FDIC job.
Select Shift was an option on that allowed the driver to manually shift the years. Are you having general transmission problems?

Do you have an E-Code showing yet? This thread has a lot of information on transmission-
 

doug7740

Active Member
Joined
Dec 29, 2014
Thunderbird Year
1955
Are there any fault codes in the transmission control module and if so what are they?

doug7740
1955 Thunderbird Blue
 
Joined
Feb 9, 2019
Thunderbird Year
2002
May be of no help at all but disconnecting the battery overnight and then reconnecting it so the PCM can "learn" optimal shift points after some typical driving may be worth a try.
 
Joined
May 25, 2021
Thunderbird Year
2003
It may be that the shifter's electric contacts for the upshift need cleaning. Or there is a loose electrical connection.
Where are the electric contacts?? Thanks for replying

May be of no help at all but disconnecting the battery overnight and then reconnecting it so the PCM can "learn" optimal shift points after some typical driving may be worth a try.
I tried it...didn't work. No error codes are showing. Thanks for replying

Are there any fault codes in the transmission control module and if so what are they?

doug7740
1955 Thunderbird Blue
Hey Doug, no fault codes. Thanks for replying
 

doug7740

Active Member
Joined
Dec 29, 2014
Thunderbird Year
1955
Looking at the attached wiring diagram it looks like the only two connectors that might have loose terminals are terminals 4, 6, 9 and 10 in the 10 pin connector at the shifter mechanism and pins 6, 14 and 22 at the 54 pin connector of the Powertrain Control Module. I would also check splice S221 in the wiring harness itself.

If you are going to disassemble the shifter mechanism, I attached the removal procedure.
1-removal.jpg 2-removal.jpg
diagram.jpg

doug7740
1955 Thunderbird Blue
 
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