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Power/Comfort switch

RenegadeT

NAXJA Forum User
Location
GSO, NC
I've pulled the 4.0L/AW4 out of my 91XJ and am using one from a 95XJ. Will the Power/Comfort switch still work, or is that built into the TCU? I am doing a complete swap, icluding ECU adn TCU. What does the switch do anyways?
 
It changes the shift points a bit. Later years without the switch are just always in "power" mode. I think comfort sucks so I never use it.

The change is entirely electronic. Mine works, but I am using the original TCU. From what I hear the TCU is the same but the wiring is different.

If you are swapping the entire wiring harness and all electronics, it will work as it did in the 95. If you are not swapping wiring and you can actually get the TCU to plug into the 91 harness, it should work as the 91 did. My 93 TCU would not plug into my 87 harness - I could have filed the plug to make it fit rather easily, but I did the easy way.

If you are actually doing a complete swap of electronics/wiring then I would personally not bother hacking anything to try and get this switch to work since comfort mode sucks so bad :D
 
good to know power mode is the default for later models.
I'm not switching wiring harnesses, just the computers. ECU plugged right up, I still havent compared the TCU's yet though.
 
yeah all it does is make you think your tranny is dying when it's in comfort mode.
 
I can't figure out the wiring diagram, and would like to remove the power/comfort switch. Any idea if I just unplug the switch (tape the wires up), will it be in Power mode?
I have successfully swapped the 95 engine/ECU/tranny/TCU into my 91, I would like to use the dash space for other switches.
 
IIRC a 95 TCU ignores the signal completely. Should be fine without the switch.
 
A little off topic but I call the "power/comfort" switch the "bad mileage/good mileage" switch!

I get 2 more mpg in "comfort" than I do in "power". I have also found that I do not get TC lockup in third gear, only OD with it in power. I have a tranny temp gauge and I have seen no difference in tranny temps between the 2 settings. I have the same "crisp" shifts in the comfort mode as well.

No lugging on my rig in comfort either but I have 4.10 gearing on 30" tires so that helps. I can pull OD down to 25 mph even on slight grades.
 
I can't figure out the wiring diagram, and would like to remove the power/comfort switch. Any idea if I just unplug the switch (tape the wires up), will it be in Power mode?
I have successfully swapped the 95 engine/ECU/tranny/TCU into my 91, I would like to use the dash space for other switches.

Doesn't work that way. If you unplug the switch you are in permanent comfort/granny mode. Try this: Unplug the switch. In the 3 wire harness plug for the power/comfort switch are obviously three wires. Make a jumper between the tan and striped wire. That will put you in permanent Power mode.
 
Doesn't work that way. If you unplug the switch you are in permanent comfort/granny mode. Try this: Unplug the switch. In the 3 wire harness plug for the power/comfort switch are obviously three wires. Make a jumper between the tan and striped wire. That will put you in permanent Power mode.
excellent. I will look over the schematic and see if i can make sense of this.

IIRC a 95 TCU ignores the signal completely. Should be fine without the switch.

this could be true, I didnt really notice any difference...sounds like the difference should be very noticeable. When I bought this XJ the 91 tranny was bad, so I never got to drive it.
 
excellent. I will look over the schematic and see if i can make sense of this.
Just unplug the switch. Make a little jumper to go into the harness plug so the tan wire and the one with the stripe are jumped. Leave the black wire out of the mix as it is a ground for the light.


this could be true, I didnt really notice any difference...sounds like the difference should be very noticeable. When I bought this XJ the 91 tranny was bad, so I never got to drive it.
 
Just unplug the switch. Make a little jumper to go into the harness plug so the tan wire and the one with the stripe are jumped. Leave the black wire out of the mix as it is a ground for the light.
yep I hear ya. Maybe its just me, but I like to understand the schematic before blindly jumping in.
 
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