Kia Wiring Problem

I have a 2006 KIA Sedona. We’ve had multi[le electrical problems due to the substndard plastics that have the cars electrical connectors crumbling in your hands when working on certain problems Our first issues with this ,now repeated problem, was the “transmission neutral safety switch”. All mechanic shops said $4,000 for the repairs and it was the mian computer, an additional $3,000, with needed to manufacture in Korea with a 120 day wait, but we found that a pin in the switch had broken off, only a5 part.

Of course working with the connector compromised it, but before we lost the wire positioning, we were able to reconnect it and use the right compounds to stabilize it.

Now the car is again refusing to go into drive again, but the replacement switch is fine, but the connector totally disintegrated, and all wire positions were lost.

We were able to find & order a replacement pigtail with the connector, but since there are over 20 different vehicles using this same connector, the wire colors on this replacement part are not the same. Therefore we have been searching to find both the wiring diagram with pin outs and also ordered the manual.

All four of my vehicles are in the shop and this was the last drivable one, so need quick help.

With the wiring diagram I think we also need a procedure to test each connection with just a voltmeter to get this right with out compromising or burning out any critical things like the main computer.

All help Appreciated!



What help do you need? Seems like you are on top of the problem.

The neutral safety switch is probably just a part of the transmission range switch. That’s going to have signals for all the ranges, P, N, D, R etc, so is likely going to have a pretty complicated connector. You’ll either need to obtain the transmission wiring diagram. Since your replacement pigtail instructions don’t have the needed info, either contact the dealership for ways to obtain the wiring diagrams, or check for the availability of an aftermarket manual, Haynes, Chilton’s etc. Your local public library might be able to help source the wiring diagrams, no harm to ask.

Your concern about damaging the PCM is valid. The range switch probably connects directly to the PCM and/or BCM. About all you can do is make sure the wires are connected to the connector properly and the battery is disconnected when you are fiddling with the wiring. Ask your parts store if they have a gadget that allows you to (safely) ground yourself to the car’s chassis while fiddling w/the wiring to mitigate static charge problems. I doubt there’s any voltage measurements that would be of any help. Focus your time on making sure the correct wires are connected to the correct pins.

A bit of common sense advice: If you plan to continue to do this sort of complex diy’er repair, the first step is to secure the necessary service data, either from an aftermarket repair manual or from a computer database service. Kia may offer such a service (good only for a short time for one car, a day, a month, etc) to Kia owners for a relatively small fee. Suggest to ask.

If you are replacing a multi wire pigtail, just remove/cut one wire at a time and attach it to the wire in the same place as the original wire, meaning don’t cut all the wires at once and try to figure out the different colors, I have spiced many pigtails that had different color wires with out a diagram, just like running the ignition wires on an old V8, if you don’t know the firing order and rotation of the distributor, replace them one at a time…

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Way too late for that, as I described, the connector completely fell apart. If we had thought to snap a pix we would not be asking for this level of help!




For what it’s worth…

When your mechanic starts wanting to “replace the computer” and/or quotes you an outrageous price for the repairs on an 18 year old car…You need to consider either:

  1. You need another mechanic.
  2. You need another car…and the mechanic is trying to tell you that indirectly.

Just my two cents.

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You have to have the correct description to find the switch and it is the “transmission nuetral safety switch”, any other name gets you absolutely nothing. Already been through thatl

Yes a wiring diagram of/for the transmission might be the right wiring i’m looking for Me and my mechanic are totally puzzled, but sure we are not using the right name for this diagram, or we probably would have found it already. We’ve been searching about 16 days now.

Nowadays, all things have specific names and you additionally find those names change from mfg to mfg.




Notice I said “The Shops”! My mechanic charges only about 10% of what they quote, but always get the quote, just for my records!


My buddy’s Pro Snap-on scanner ($6K) has the wiring diagram for the transmission we just checked out yesterday as well as the connector (plug) for the TCM and had a picture of the connector showing all 60 (IIRC) pins, as well as the 20 pin connecter at the transmission … So you might have to find someone that has a Pro scanner that will have everything you are looking for… That might be why all the other shops are 90% higher then your guy, having the correct equipment/tools makes ALL the difference in the world…

Or you are going to have to find someone with access to a paid subscription to a pro level repair info like All Data, Mitchell, Identifix are a few examples…

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I doubt a separate diagram exists just for the switch. More likely is part of the car’s transmission wiring diagram.

Have you been following the other discussion about the Mazda with the faulty transmission control module?

It legitimately had failed . . . and it’s a common problem for that car

Sometimes “the computer” really is the problem

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what you want is a connector pin-out


Same with the 09 Cobalt trans issue I am dealing with, bad TCM… I can read the turbine/input speed sensor signal normal all the way up to the TCM, but the TCM shows it dropping off/out, what else do you (ledhed75) think it would be?? I even have a tread about it… lol

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Unfortunate circumstance. I was surprised to see where this switch is located. You’d think they would use plastics that are capable of withstanding that environment. Is there any chance the parts have been exposed to harsh chemicals like when cleaning the engine bay?

In what limited capacity I have, I wasn’t able to find anything showing the original wiring/colors in the harness connector or any schematics/wiring diagrams.

I was surprised to see how many terminals the switch has. Conceivably, once you have the original colors/positions, it should be a simple exercise to wire in the new pigtail. I don’t see any benefit to testing. Good luck finding the info. Personally, I might visit a dealership parts counter and plead my case to the counter person. They should have access to all the info, at least they used to when I was doing my restorations and needed some info I didn’t have. Go at a non-busy time…

I don’t dispute that car “computers” do go bad from time to time. And I don’t have a better solution from my distant internet browser window.

The message I was trying to convey was… it’s rare (but not impossible) for The Computer to go bad on a modern car. More often than not, the problem lies in some other obscure sensor or wiring harness. “Replace the computer” is often an expensive, Hail Mary attempt to use a sledgehammer on the nail, and/or scare off the customer when the shop doesn’t want to deal with the issue. And on an older car (especially a Kia)… I would question putting much more money into repairing it.

But again…your mileage may vary.

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I’d guess it depends on where it is located. If located like my Corolla’s, inside the passenger compartment high and dry, away from direct heat sources, PCM failure seems like it should be pretty rare. But if located in the engine compartment, esp if near direct heat sources, or if it can get wet, considerably more likely. It’s going to vary by car to car too. PCB-electronics design is quite challenging if it has to work over a wide temperature range. The car buyer can only hope that the engineers who design their car’s computers are up to the challenge. It’s definitely not easy.

I have the right mechanic, but even with a voltmeter, without the diagram, you can not get the wiring right and you must be sure or you will blow the expensive main CPU



There are only 10 pins on the TNSS, so wrong diagram. There is also a 9 pin connector, but had to eliminate that when looking for the pigtail.

Entering the following, in Google, staring to get some promising results, but nothing definite yet:

“wiring diagram for the transmission neutral safety switch for a 2006 KIA Sedona”

Still looking and being a computer junky, controls expert, and master electrician I will positively know when I see the right diagram!



Yes and what each wire, by pin is and where it goes. My understand is there are 2 voltages here, 12 vdc for connecting the starter in both Park & Neutral & the backup lights in Reverse and 5 vdc for connection to/from the main CPU, which is why this is so sensitive as wrong voltage on a wire can blow that CPU!


Not pertainent, but thanks!