Drivetrain Tech General discussion of drivetrain for the Ford Ranger.

No response to downshift "button"

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Old 2 Weeks Ago
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No response to downshift "button"

1999 Ranger 3.0 automatic 4X4 - - - when I push the button on the end of the shift lever, it doesn't downshift out of OD. If I use the gas pedal, it does. Electrical issue, but where's the likely disconnect?
 
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The OD button prevents shifting to Over Drive it doesn't cause transmission to downshift if it was already in OD, but once it downshifts to "3rd" it shouldn't shift back to OD if "OD off" light is on

The button is called the TCS(trans control switch), it is a 12volt toggle switch to pin 29 on computer(PCM), not a constant voltage switch, its a momentary switch
PCM always starts up with OD on
If TCS sends it 12v then it toggles to OD off
If TCS sends it 12v again then OD on
So it toggles between OD on and off each time its "sees" 12v on pin 29
 
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Old 2 Weeks Ago
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Originally Posted by RonD View Post
The OD button prevents shifting to Over Drive it doesn't cause transmission to downshift if it was already in OD, but once it downshifts to "3rd" it shouldn't shift back to OD if "OD off" light is on

The button is called the TCS(trans control switch), it is a 12volt toggle switch to pin 29 on computer(PCM), not a constant voltage switch, its a momentary switch
PCM always starts up with OD on
If TCS sends it 12v then it toggles to OD off
If TCS sends it 12v again then OD on
So it toggles between OD on and off each time its "sees" 12v on pin 29
I worded my question wrong, but you got the gist of it! No "OD" light at any time............would you suspect the TCS itself? The button and wiring in/on the steering column/shift lever are pretty straightforward. I'll get out my shop manual/wiring diagram and study it a bit. Is the TCS in an accessible location?
 
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1999 Ranger
You can check fuse #27(15amp) in cab fuse box, thats the TCS's 12volt power, but its also Reverse Light fuse, so if you have backup lights then fuse is OK

There is a code that should be set if wiring on TCS is a problem, P1780 - TCS Circuit Out of self Test Range
 
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