oxnfoxfox

From what I understand this code is for a bad speed sensor.

Full story- I put a splice on my positive battery cables and in the process when the battery was hooked up an exposed portion tapped the a/c and sparked(Not sure if this has anything to do with it but thought I should mention it)

Today I was droppig kids off at school and I had a check engine light so I go home and I get a 41. So I start the vehicle and disconnect the battery and it still runs so perhaps it just didnt kick in due to how cold it is out here and the fact it was just sitting and idling. Voltmeter seems to be reading fine at around 14. I also reset the check engine light and at this time I am no longer getting a code 41

Then when I take it around the block I notice the speedo isnt working and I get the code 15.

My first question is, could the positive cable briefly touching the A/C have shorted out some sensors or even screwed up the alternator?

Question 2 is, From what I understand there are 2 speed sensors right? One input and one output? Someone please explain to me......I think all i need is the sensor that connects to the transfer case and I should be good to go right?


Side notes- It is very cold where I am and its been snowing and raining alot.

gat

15 - no distance sensor signal detected by computer. Check circuit. Replace the sensor.
41 - alternator field not switching properly.
My guess is that you destroyed the diode when you directed flow in the opposite direction.

gat

If you disconnect the negative terminal first and reconnect it last, then you won't have these problems. I sent a message to you about the distance sensor. I hope that it helps.

oxnfoxfox

the diode in the alternator?

Like i said code 41 came but then has not come up since. Additionally I removed my battery while the vehicle was running and the jeep continued to run so I got to assume the alternator would be good right?

any expolination for code 15 tho? Why it would all of a sudden not work?

gat

Maybe it was that arc or maybe it wasn't... Inspect, then replace provided that you don't see an issue.
i figured the diode in the alternator. If it works at +2v over battery when running, then it is still working.

tjwalker

Never ever disconnect the battery cable from a running vehicle. This was a very "old school" trick for non electronic vehicles years ago but it comes with very high risk on any XJ. An alternator and charging system issue can often be diagnosed with just a multimeter or by having the alternator tested.

Here is a link that explains why this shouldn't be done in detail. Spike and transient voltage can do harm to your electrical components, mainly alternator and computer.

http://www.troubleshooters.com/dont_...ct_battery.htm

If your code 41 comes back, that code is almost always a failing alternator.