So my 2016 Jeep Patriot just threw a U0401 code, and my engine light is on. I’ve also noticed I’m going through a lot more gas than usual. Anyone know what might be causing this? Got the battery replaced about 4 months ago too. Would appreciate any tips!
I had the same code pop up a few months ago. It was a communication issue between the ECM and PCM. Have you checked the battery connections since you replaced it?
Paxton said:
I had the same code pop up a few months ago. It was a communication issue between the ECM and PCM. Have you checked the battery connections since you replaced it?
Nah, I didn’t think about that. I’ll take a look. Could that really cause the U0401 code?
Paxton said:
I had the same code pop up a few months ago. It was a communication issue between the ECM and PCM. Have you checked the battery connections since you replaced it?
Yeah, it can. If the battery’s weak or not connected properly, it could mess with the signals between the ECM and PCM.
I had this issue and it turned out to be a blown fuse. Might want to check those too, just in case.
Ridge said:
I had this issue and it turned out to be a blown fuse. Might want to check those too, just in case.
Good call! I’ll check the fuses when I look at the battery connections. Thanks!
Could be the alternator too. Had a similar issue, and my alternator was on its way out.
Yan said:
Could be the alternator too. Had a similar issue, and my alternator was on its way out.
Yikes, I hope it’s not the alternator. How did you figure that out?
Yan said:
Could be the alternator too. Had a similar issue, and my alternator was on its way out.
I took it to a shop, and they ran a test. They said the alternator wasn’t charging the battery properly, which caused a bunch of codes to pop up.
Yan said:
Could be the alternator too. Had a similar issue, and my alternator was on its way out.
Got it. I’ll check the battery and fuses first, but I’ll keep the alternator in mind if those don’t fix it.
Is your Jeep driving weird besides the engine light and gas thing?
Lyle said:
Is your Jeep driving weird besides the engine light and gas thing?
Not really. Just the engine light and bad fuel economy. Drives pretty normal otherwise.
Lyle said:
Is your Jeep driving weird besides the engine light and gas thing?
Yeah, sounds like it could be an electrical issue then. Good luck!
If you don’t find anything, you might need a scan tool to really see what’s going on with the modules.
Oak said:
If you don’t find anything, you might need a scan tool to really see what’s going on with the modules.
True, I’ll try the DIY stuff first and then maybe head to a shop if nothing works. Appreciate the advice!