Tranny control module

BlackVert

15 Year Member
Oct 3, 2003
5,589
9
98
Bethesda, MD
Apparently there is a TCM back behind the glove box somewhere. How do you get to it? Or, perhaps, how do you take the glove box out? If I can get that out, it would probably be pretty easy to get to the TCM.
 
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You sure you are not thinking about the PCM (Powertrain Control Module)? That’s the main computer that controls both the engine and the transmission.

It’s located behind the passenger side kick panel, below and to the right of the glovebox, just ahead of the passenger side door (at foot level).
 
Actually what he is talking about is called TCSM (trans control switch module).
It recieves signal from the TCS (trans control switch) and is used by the PCM to determine automatic shifts and to operate the TCIL (trans control indicator lamp) to indicate 4th gear has been disengaged.
Basically on this model they used a module to lock out OD and turn on OD light.
 
The main thing the TCSM does that I know of is to toggle OD. The black box is about the size of a large pack of chewing gum. It has a white sticker with black numerals for the part number. It's a 5 wire affair in a 6 pin connector.
 
I'm not an auto kinda guy so I know very little about them
but
I think I've seen Don say to those who go from stick to auto

They won't work correctly if you don't have that module :D

Grady
 
You just reach behind the glove box and you can feel it. We pull them from auto 94-95's when we go junkyarding because they are impossible to get new. The supply is dwindling. I had 2-3 of them but used them all recently.

Even Jerry W. told me that they are just used for the OD light, and you really didn't need it, but guess what, the tranny had major issues with OD when it was not there. I've seen this on a couple of swap cars. So you really do need it.
 
i'm guessing it is that white thing behind the trunk release switch. am i right?

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Even Jerry W. told me that they are just used for the OD light, and you really didn't need it, but guess what, the tranny had major issues with OD when it was not there. I've seen this on a couple of swap cars. So you really do need it.

by major issues, do you by any chance mean that it would not shift into overdrive?

that is what mine is doing (not shifting into OD) and i have been unable to figure it out as of yet, nor have i found anyone willing to look into it for me.

i have heard that when voltage is applied to pin 41, that disables OD on the computer.

so as a test, can i put a switch in the wire that goes to pin 41 and open the switch?