Keith Dickey

Hey Guys!

I was having some idle issues, so I changed out the CPS. After the change my check engine light came on, so I unplugged the CPS and plugged it back in. The light went off. I drove it about 70 miles yesterday and the light came back on, but it seemed to be running fine.

I went to go to work today and about 10 minutes on the highway the battery light came on, too. I drove it back home and pulled the DTC. It was code 41, short in the generator field. What should I do to diagnose the problem? Multimeter on the terminals and rev it? It sounds like an alternator regulator to me, but I'm not that experienced.

Anything helps, thanks!

Jeepwalker

I hate those intermittent issues too!
I had something like that happen and it turned out to be other wires that I forgot to hook back up. Might be worth tripple-checking. Ensure your battery connections and the ground to the engine (and body) are clean and good.

When the light comes back on, yes, put a multimeter across the terminals to check voltage. Should be around 13.8 or higher as the engine is rev'd. I'm sure other guys will have some other ideas.

Keith Dickey

Jeepwalker,

Thanks for the response! I haven't checked the battery terminals in a little while, hadn't even thought to check them for this. I'll give everything a little 'wiggle' when I get home and see if that fixes things!

tjwalker

The code 41 is almost assuredly not related to your crank sensor issue.

The vast majority of the time on the 4.0 liter Jeep engine, a code 41 is related to an internal failure in the alternator. You can have it tested. Pretty sure though that you are on your way to an alternator replacement.