I'm having trouble finding the source of my overdrive troubles. I can not shut off overdrive. No light, and overdrive does not shut off. I've replaced the switch and the entire column assembly... neither made a difference. Anyone know where the three wires the switch plugs into end up? I'd like to test them for continuity. Is there a switch or something in the tranny? or the torque converter?

'00, 5.4l 4r70w tranny

Any other ideas of where I should be looking?

Thanks

 

The wires all go either to the PCM as either an input or an output or to a power bus line. There is no direct connection to the transmission from the switch.

I can look up the schematic Sunday or Monday and give you the pin numbers if no one has provided them in the meantime.

I will assume you will have a multimeter available.

 

Yep. The TCS & TCIL are directly connected to the PCM & nothing else.

 

Turned out the terminals for the fuse were spread too wide. I can't tell ya how frustrating it was running that one down...

Thanks for the earlier replys!

 

Glad you found it. I was going to tell you to change the fuse.
That fuse also controls some other functions that you did not miss yet..
Could have saved some money and time for you.

 

I won't tell you how many times I pulled that fuse and looked at it, switced it, or cleaned up the ends... lol