95 XJ - Way to add comfort/power button for trans?

[Blaine B.]

Just curious if it is possible to add a comfort/power button for the trans to a 95 XJ? Not sure if it would need a different control box or what, if you could just wire it up and all...thanks!

[Big Red]

I've really only seen these used in the Renix 4.0Ls 87-90'. I had one in my 1st XJ my 89' 2 dr AW4/242

You might be able to duplicate this with a computer chip or a control module. I think they make one for your year. I rarely messed with this option on my 89'. You will see a lot in a auto trans by how heavy or light your right foot is on the skinny pedal anyways. If I were you I'd get the performance chip and/or Brett's shift kit so you can shift when you want with the turn of a rotary switch, or his bling bling paddles, video game joy stick etc.

Troy

[5-90]

You would probably have to graft in a RENIX TCU - but the HO was hardwired into the "Power" setting anyhow. Since the Power setting also firms up the shifts somewhat, it is also good for causing less wear on the clutches in the transmission, which is probably why it was done that way. The "Power/Comfort" toggle is a silly idea, and I'll usually hardwire it into "power" myself and just use the toggle for something else (like auxiliary lighting...)

5-90

[BrettM]

it's hardwired into Power, the Comfort setting is useless in my opinion, so just forget about it.

[Blaine B.]

Ah, I was just curious anyway. Easing off of the pedal and keeping it below 2200 RPM only gains me 2 tenths of a MPG, btw :music:

[90xj06]

the confort is all messed up. it newer works right and it shifts alot at 40 mph.

[Big Red]

Take control of your AW4 with Brett's kit...that is all. :D

[langer1]

The older Power Comfort switch should have been name "Power" or 'Economy".
My 87 gets 4 mpg more in comfort mode.
18 power. 21 comfort mode

[Blaine B.]

Is that highway or city?

Splendid mileage eiter way!

[90xj06]

i get like 4 mpg all the time i think i need a sync sensor in the disco.

[Matthew Currie]

Like Langer, I noticed an actual difference in my 87. I averaged about 23 in daily driving (mostly rural).

[BrettM]

the comfort/power switch shouldn't affect highway mileage at all since it only changes the shift points, but I am very suprised to hear how much difference it is making around town.

[Oizarod115]

my brothers 90 also gets way better mileage in comfort than power. up hills one tap of the power button its a huge difference.

[DansGreyMj]

what yrs did they use those cuz i heard it was up til like 91 but my couzins 95 had it from the factory

[512TR]

Somebody have to give it a try...:-)

Here's the TCU wiring for the 88XJ/MJ and 93XJ.

On the trucks without Power Switch there is constant 12v to the TCU's pin C11 (ignition on)

As fare as I can see, the only thing to do is to cut the tan wire from TCU pin C11 and install a switch w/control light.


-93 without
http://i4.photobucket.com/albums/y115/512TR/Wiring%20diagram/TCU93-AW4.jpg

-88 with power switch.
http://i4.photobucket.com/albums/y115/512TR/Wiring%20diagram/TCU88-AW4.jpg

[sp4mike]

I have it on my '91 so it wasnt just for the renix. Just an fyi. I never put in the 'power' mode and I get about 20mpg on the highway.

[Runnin'OnEmpty]

My 89 got 25 mpg on a highway trip once, in comfort mode. My 96 dosen't get anywhere near that mileage, and the shift points are at a higher rpm. Surely the power/comfort switch can't be the reason.....?

Someone needs to do this mod (breaking the #11 pin circuit), and report back to us less adventurous individuals.....

[Saudade]

Someone needs to do this mod (breaking the #11 pin circuit), and report back to us less adventurous individuals.....

Isn't this the "comfort" position?

[Runnin'OnEmpty]

I think it would be, according to the posted wiring diagrams. I always ran my 89 in the "comfort" mode, and it seemed to shift quicker at a lower rpm than my 96. (Under normal driving conditions.)

[cap269]

Just a side note... on my '96 sport, there is no wire connected to TCU C11. The spot on the connector is empty. So, I guess the hardwiring is actually inside the controller for my model. If that is so, would one be able to just use a controller from a diff year? Say, from a 1988? And then just add the wire to the connector at C11 and run it to the switch? Hmmm...

[sjx40250]

I am not sure that will work. I have a TCU from an 89 and replaced my 91 TCU for a day. Didn't work all that well. Switched it out as soon as I got home. It does work on my 90 though. How it is wired may be the same or nearly so but what about the circuitry? The PN's for the TCU are probably different.

[Blaine B.]

With your 96 you have OBD2 so swapping in an older TCU might not work with OBD2....although you could try it.

[ehall]

This thread is old but since it was bumped by somebody else... the TCU uses signal from the TPS and other inputs to make decisions, so mixing TCUs across different generations TPS is unlikely to produce desired results. You'd have to replace the TPS and that would just cause other problems with the other systems that also read that data.

[stesul411]

Actually it can be done and was standard on export XJ's up until at least 95', as can be seen in a few of the pix from gojeeps site. Page down through the article and you can see a POWER/COMFORT switch to the left of the steering column.

HERE: http://www.go.jeep-xj.info/HowtoDashClock.htm

AND HERE: http://www.go.jeep-xj.info/HowtoDashCarbon2.htm

[MJR]

BTW the 91 HO had the Power/Comfort switch. You'll have to add wires and get a 91 TCM.

You could use a 87-90 TCM but you may have an issue with the TPS since the Rennix use a 2 sided TPS and the TCM powers the half it uses as opposed to the 91-up which splice into the engine (uses the 5V provided by the PCM) and use a single side TPS.

But as others have stated why bother really.

I am not sure that will work. I have a TCU from an 89 and replaced my 91 TCU for a day. Didn't work all that well. Switched it out as soon as I got home. It does work on my 90 though. How it is wired may be the same or nearly so but what about the circuitry? The PN's for the TCU are probably different.

I have a 95 TCM in my 88. I just had to wire the TPS signal to work off the engine side. See notes above.

[MJR]

Actually it can be done and was standard on export XJ's up until at least 95', as can be seen in a few of the pix from gojeeps site. Page down through the article and you can see a POWER/COMFORT switch to the left of the steering column.


US models it's on the right side of the column

[stephenspann27]

Aren't' the shifts more firm in "power" mode.. making for less clutch pack wear? I've always run my in power mode.. cause I'm a man :-P *grunt* *grunt*..

[ehall]

shifts are higher RPM which makes them firmer

[stephenspann27]

Could it be argued then.. that running in "power" mode leads to longer tranny life? So that its not slushing and slipping "softly" into gear..

[MJR]

Aren't' the shifts more firm in "power" mode.. making for less clutch pack wear? I've always run my in power mode.. cause I'm a man :-P *grunt* *grunt*..

The firmness of the shift is controlled by the throttle position (line pressure cable). As ehall stated it's be cause to throttle is open more that the shifting is firmer.

[DWRDodge6.7]

I had this on my '89. I very rarely used the comfort setting. Even on comfort the very best that it did was 22mpg on the highway. Both the '96 we had and the '98 that we still have got/get better mileage. This '98 will easily do 26 on the highway at 110 kph with 31" tires. When it was new, with stock tires, it got 28 mpg. Figures are hand calculated in Imperial.

[kastein]

I am not sure why anyone would use the comfort mode (I guess Chrysler agreed with me...)

Accidentally put my knee on the power/comfort switch on my friend's MJ while driving it down to NJ to pick up a new transmission for my rig, didn't realize it for a while and was worrying that I might have just fried the transmission in his somehow. I don't like that kind of surprise.

[alex673]

I have a power/comfort button on my 95 Limited, and to be honest, I never use it... I leave it in the power mode all the time and it makes no difference to my gas mileage or driveability.

Cheers
Alex