I recently bought a 87 pioneer and have a question about the transmission power selector, comfort vs power mode. I can't tell any difference between the two modes which leads me to believe the selector isn't working. The light comes on in the switch but I don't notice any change. Is there a way to diagnose It to see if it is working? Also is this a typical problem? Should it be disabled? Thanks in advance!

 

A lot of people disable the comfort mode.

 

If I were to disable it how is the proper way to do that. Is there a way of determining what mode I am currently stuck in? I haven't driven another jeep with this option so I don't know how it should feel in which mode.

 

First, make sure the 7 amp fuse in the "trans" slot of the fuse box isn't blown. Then do this:

Bypassing the Power/Comfort Switch on a Renix Jeep

Remove and unplug the switch. In the harness are 3 wires One has a stripe, one is tan, and the other black. Make a 4" jumper wire with a male spade at each end. Plug one end in the cavity for the tan wire and the other in the cavity for the striped wire and you'll be in permanent Power mode. Stuff the harness back in and reinstall the switch for looks.

If you happen to have a 91 or 92 XJ/MJ and it has the Power/Comfort switch, just jumper the Tan and Blue wires in the harness plug.

NEVER include the black wire when jumpering!!!

 

Thanks for the help Cruiser! I was really hoping you would see this and chime in! I've been stalking the site for a while and have really appreciated reading your expertise! I've been going thru your tips for renix engines.

I hope to implement your fix for this problem this week then next up is the c101 elimination! Thanks again. Will post when I get this done to let everyone know how it works out.

 

Cool. 1 through 5 or 27 and you'll be good to go.

Do you know about the 89 and later ECUs? 88 and later TCUs?

 

Not yet. I'm trying to get spun up on everything I need to know about the Renix.

 

Well, the 88 to 90 TCUs have better shifting manners.

89 and 90 ECUs give you more power.

 

Thanks for the tip! I assume those are best gotten from the jy? I am starting to have quite a list of stuff I need to pilfer from the jy. I'm trying to make this baby as reliable and comfortable as possible at the moment. Gotta do my interior lights as only about half seem to be working!

 

First I would suggest doing a kickdown cable adjustment to lose the slack (on any auto 4.0)

This will help the shifting/downshifting make so much more sense. After that, there is simply no reason to have comfort mode on. I have tried to live with it for the sake of possible gas mileage and for my wife so that she doesn't learn to drive with a lead foot/fast acceleration, which the power mode definitely delivers more than comfort. It's just total crap, though - comfort mode makes for choppy shifts and generally makes no sense and makes you think there's something wrong with your trans the whole time. No bueno. Even on the highway it doesn't help, since it won't make a difference once you get up to speed anyway, and comfort mode can cause weird, jerky downshifts when you don't expect them.

 

Yep. JY. If you have an auto trans, get an ECU from an auto trans 89 or 90. You can use the auto trans ECU on either auto or manual but a manual eCU can give idle issues when used on an auto model.

 

Mines always on power. Don't really like how it shifts in comfort.

 

Looky what I got as a gift today via email!!

 

It's always nice to have a visual aid! Thanks!

 

what's the point of bypassing the switch? isn't it the same as just leaving the switch in power mode? Or is it not that simple?