accidentally towed dead 96 xj in neutral

Good day, My 96 country with nearly every option went dead and with a friend we towed it to the tech. With a newly rebuilt computer it now runs but the tach does not work and it still drains the battery and the check engine light stays on and the tech says it is the pcm for the trany. Has any one heard about this happening or had the same trouble? thanks for any help.

Exactly what Check Engine Light code was downloaded ? Have you tried a used Transmission Control Unit (TCU) ?

When I first drove it around and shut it off, I checked for codes and all I got was the check engine light with out any flashes. No, I have not tried a controller from another xj. What is the interchange on that? Thanks

First things first. Get the codes pulled from the PCM. Autozone does it for free. If it's shifting okay, the TCM code probably just says the neutral saftey switch needs cleaned (google on Jeep NSS cleaning).

Also, does the key return all the way to the run position after you start it? I had a bad ign switch that didn't spring all the way back to run that caused the same symptoms - dead guages, check engine light still on, and the blower didn't work. Nudge it back to the run position and it went back to normal.

All of the other gauges work including the speedo and all we have up here in the mountains/sticks is o'riellys. I will check with them on the code issue. thanks

We have an O'Reilly's here in Sheridan, Wyoming and they have let me use thier code checker before for free. I am assuming they are pretty much all the same. At any rate, give them a try I would be willing to bet they have one.

I would fix the battery drain situation first, then worry about the rest.

would a dirty NSS cause the battery to drain? thanks

no...the dirty NSS would cause a lack of back up lights and not being able to crank in park or neutral.

You can Google "locating auto parasitic draws" and get a ton of info.

Quick and dirty, disconnect the battery cable from the battery's negative terminal. Fully charge the battery.

Now, attach a 12 volt test light in series with the battery cable and the battery's negative terminal.

Now, for a little background. Modern vehicles will ALWAYS have a slight parasitic draw. The PCM, the radio memory presets, that kind of stuff. That draw should be less than 50 mAmps, more like under 30 mAmps.

Ok, with a NORMAL parasitic draw of 50 mAmps or less the 12 volt test light placed in series with the negative cable and negative battery post will only have a DIM GLOW.

IF THE LIGHT GLOWS BRIGHTLY the parasitic draw is excessive and is killing your battery.

You can also use a multimeter to measure the parasitic draw, most meters have a 10 amp max draw circuit. However, the 12 volt test light is better BECAUSE of what you will find out next.

IF the parasitic draw is too high, you need to locate the circuit with the problem, then the part of the circuit--wiring harness or component--that is the specific cause of the problem. WITH THE 12 VOLT TEST LIGHT GLOWING BRIGHTLY it is quite easy to pull a fuse, look at the light, no change then that circuit isn't the problem. Keep pulling fuses until the light goes dim. IF YOU USE A METER, EACH TIME YOU PULL A FUSE YOU HAVE TO RUN OVER AND LOOK AT THE METER'S DISPLAY.

Keep pulling fuses one at a time until you locate the circuit. Note that you may not find the problem just by pulling fuses, you may have to disconnect harness connectors and/or components--a/c, aux fan, blower motor, etc., to nail things down. You can even have something behind a fuse block or under the PDC causing the problem.

Good luck.