I bought a rail shifter from RA Designs and since I have a '99 I expect it to throw an error code when I put it to use. I don't want to deal with the check engine light being on every time I use it, so I'm considering just pulling the bulb behind the instrument cluster. Still, I'm worried that I may throw another code without knowing it. Any ideas? Should I just plug in a scanner and check it weekly? I would think that anything that caused the CEL to come on would also be evident in a drop in engine performance. I wonder if I could just relocate the light to a less conspicuous location...

 

Has anyone gotten away with just pulling the bulb for the check engine light?
Here's the site for the rail shifter
http://radesignsproducts.com/14Shiftcontrollers.aspx

Even though I 've already purchased it, I think this one may be more compatable with my year:
http://montanafab.com/products/

 

I pulled mine, but I'm in a state that dosen't do inspections. I run the Edge chip, so my CEL was always on. When I was in CA (smog test) and NC, you would fail inspection if your CEL light was on. No matter the reason. Also, I believe they might (said, might) hook up a OBD scanner to the car now.

I'm interested in the RA Design too. I did a little research on it and building your own last year. I really don't think the CEL will come on.

 

Man I really like the Montanafab setup. Its a complete plug and play system. And doesn't throw any cell codes. The only wire you have to splice in is for the illumination wire for the illuminated shift locations for the dial switch.

Unlike RA Designs where you have to splice in each wire for the 1st & 2nd gear shift silinoids. The only thing I think I like better about the RA setup is the cool little rail shifter.

But eventhough the Montanafab setup doesn't have the cool rail shifter,.. but a small toggle dial switch that's illuminated is still a much better setup in my opinion.

 

I have a rail shifter waiting to be installed as well. I have the same question bout the cel since I have a 2000. I read somewhere that a guy hooked up resistors to fool the tcu into thinking it was still connected to the trans. If a guy could get the right resistor it might be a good option. Otherwise I was planning on putting a piece of electrical tape over the light and roll the dice on throwing other codes.

I looked at the montanafab as well, but my understanding is that it only keeps the trans from shifting up/higher than the selected gear. Which is fine Offroad but I want to be able to hold it in overdrive on the highway.

If you figure something out post it up and I'll do the same. I assume you have found online the location of the tcu and colors that need spliced because the directions don't show for our years.

Here's a good writeup:

http://www.naxja.org/forum/showthread.php?t=1063881

 

Yeah, Post #13:
http://www.naxja.org/forum/showthread.php?t=1034635
(there's more in the following pages- read on)

Apparently the TCU needs to know that there's a certain load on the soleniod circuits. They have some luck with getting the CEL to stay off except when they use engine braking, which I never do. I'm heading over to Radio Shack this afternoon to see if I can build that circuit.

 

I noticed the montana fab shows 1,2, D Im not schooled at all on the aw4 but is that normal I thought that tranny is a 4 speed. Dont take me the wrong way, im trying to learn the ways of the auto tranny , my xj is a 4.0 but hte shifter is 1,2,d. ? aw4 ? is that the reason for the shift rail . I dont understand the benifit. School me on it thanks for all the info

 

I put my rail shifter in today and defeated the CEL!

I ended up just using 2 clearance lights instead of resistors and it works perfect. The lights light up as the tcu "shifts."

I used 2 2pdt switches because that's all I could get in town. I plan to get a 4pdt and only have one switch to move it from auto to manual.

 

The shifter is 1-2,3,D. The 1-2 selection is controlled by Chrysler's programming of the TCU, which sucks. The shift range of 1-2 is so far off that it would be better to have manual control of it.

I ended up building the circuit in that link above (thanks to Raneil from NAXJA) and it works. I also went the boneyard and pulled the TCU and plug from another XJ to use as a bridge rather than clipping into my own harness. I removed the female end from the JY TCU and soldered the harness on its back, so now I just plug the whole assembly in between my TCU and AW4.

It took me a while to get the hang of it, and I think I'll need some sort of indicators to show what gear I'm in when I switch to manual control. I was still able to get the CE light to turn on, but only when I completely unlocked the torque converter and tried to engine brake in 2nd. By the time I got home though, it had gone off.

Here are some of the pics of all the wiring I did underneath the console (the second smaller harness doesn't tie into the rail shifter, it's for my compressors and an Extended Idle switch).





I'll put up some more pics of the top of the console when I get my dash back together. I think I may still include some indicator lights - pin 1,2,and4 on the transmission range sensor plug have +12v when engaged so that may work...