Hello all,

I have an issue currently where my Jeep (1989, automatic, 4.0) won’t downshift when I try to give it more gas while going up a hill which in turn makes
me slow down and barely make it up said hill.

checked TPS, drove both with plugged in and not, made no difference.

checked TCU and adjusted tv cable with no differences.

it shifts pretty early from 1st to 2nd but is nice and smooth through all the gears. Just doesn’t want to down shift.

just need another place to look/suggestions kind of lost on this one.

thanks all.

quick edit;

I should mention I can’t get over 2k rpms while it’s trying to get up the hills, I’ve tried tapping breaks and letting off accelerator, etc. normal driving I don’t ever even get over 2500 rpm, so maybe a different issue all together?

 

Try downshifting it manually.

 

You used a voltmeter to check that the voltages on the square connector changed appropriately, right?

 

TPS controls that function. There are 2 connectors on the TPS. One for engine control and one for trans control.

If it were mine, I would go to www.cruiser54.com and complete Tips 1 through 5 and #10 before doing anything else.