Dreaded check engine light

[alphawolff]

Going to for at least documentation purposes hopefully they can find it and fix it just dropped it off at the dealer and he said that his battery monitor module issue which could be caused by something like a ground wire
The way he described it is all these different modules go into a central campus so it conceivable if I had a loose ground wire in the auxiliary switch panel for like aftermarket lights that would disrupt the signal to the battery monitor module, and we would not be covered on the warranty
Which I suppose I can understand
How often does the battery monitor a module go bad and would a previous dead battery cause this?

if you repeated that verbatim then that gentlemen is spouting complete bullshit

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[wanderer]

So the dealer says that the code P058a is a low voltage reading for the battery Monitoring module. He says it could be just a loose wire( after looking at the ground wires on my aux switches for my lights) However. the. check engine light did not come on until after they replaced the o2 sensors. And I have had the lights on for about a year. So no way do think it is a loose wire. I think the dealer doesn't want to cover another warranty claim caused by their shit work . Please check my thinking on this .

 

[jadmt]

Did you ask about the tsb i posted?

 

[Scotty Scout]

I think that you need to let go of the O2 sensor replacement. It doesn't have anything to do with the current CEL. Personally, I would take my Jeep to a different dealership. I know its a pain because it sounds like you will have to drive a long distance for that to happen, but it might be worth the effort.

It really rubs me the wrong way when they start wasting time and energy hedging responsibility for a problem rather than simply fully diagnosing the issue. Get out of there. Take your Jeep to a dealership that will be fully focused on diagnosing the issue rather than thinking of possible ways it might not be a warranty claim.

 

[mwilk012]

I think that you need to let go of the O2 sensor replacement. It doesn't have anything to do with the current CEL. Personally, I would take my Jeep to a different dealership. I know its a pain because it sounds like you will have to drive a long distance for that to happen, but it might be worth the effort.

It really rubs me the wrong way when they start wasting time and energy hedging responsibility for a problem rather than simply fully diagnosing the issue. Get out of there. Take your Jeep to a dealership that will be fully focused on diagnosing the issue rather than thinking of possible ways it might not be a warranty claim.

Do you work for free?

 

[wanderer]

WELL. bs is bs any way you put it >. When this saga first started there several "electric module codes" aside from the o2 sensors codes. They had the jeep for 9 days. waiting for the o2 sensors. to come in. When I asked about those electric module codes, while picking up the jeep he said they weren't coming up any more. So he figured it was taken care of. (b.s.)So did I. But they weren't and they are back. It is just irritating to have to make multiple trips , waste of time and money. they don't make the jeep un-driveable. but it needs to get done.

 

[mwilk012]

WELL. bs is bs any way you put it >. When this saga first started there several "electric module codes" aside from the o2 sensors codes. They had the jeep for 9 days. waiting for the o2 sensors. to come in. When I asked about those electric module codes, while picking up the jeep he said they weren't coming up any more. So he figured it was taken care of. (b.s.)So did I. But they weren't and they are back. It is just irritating to have to make multiple trips , waste of time and money. they don't make the jeep un-driveable. but it needs to get done.

You just have a fundamental misunderstanding of everything involved here.

 

[alphawolff]

So the dealer says that the code P058a is a low voltage reading for the battery Monitoring module. He says it could be just a loose wire( after looking at the ground wires on my aux switches for my lights) However. the. check engine light did not come on until after they replaced the o2 sensors. And I have had the lights on for about a year. So no way do think it is a loose wire. I think the dealer doesn't want to cover another warranty claim caused by their shit work . Please check my thinking on this .

this is completely unrelated to o2 sensors.

this is talking about your IBS on your negative battery terminal. it has two wires, one 12v+ and one lin bus. using a DMM check the circuits and verify you're getting roughly b+ voltage on the red wire, and roughly 10v on the other wire. if these are good replace your intelligent battery sensor. if the red wire doesnt have power check the fuse.

or just replace it and see what happens i guess. takes twenty seconds.

 

[wanderer]

“You just have a fundamental misunderstanding of everything involved here.”
Yeah, I get that. I probably do but I think these are two separate events that occurred nearly simultaneously because when I was on my camping trip, the battery went dead one night so I just jumped it but at the same time the check engine light for the O2 sensor had to come on. I think they were two separate events and I told the dealer that when I initially took it in he only fixed one of them, which was the O2 sensors

I think the other one remains something completely different cause unknown,
Cause I really don’t understand how a dead battery could do something like that

and the mere fact that they occurred at a similar time is just coincidence

on the other hand. You’re right I’m completely ignorant of The more modern electrical systems in jeeps and stuff that we deal with.

 

[wanderer]

So I can see by reading over this thread that I kinda got things a little confusing to people that are reading it so chronologically went like this
Packed up for my camping trip backing out of the driveway check engine light comes on. The code is o2 sensor.
So I reset the code with OB d reader and the jeep is running a little bit rough but after 30 miles it smooth out
Everything is good for a day or two then the code comes back on again. It’s O2 sensor. Look it up figure it out and say what the hell I’m already on my trip so I keep going first night I camp in the Sequoias someplace.
Got my new refrigerator working good leave it hooked up with the battery monitoring system built into it so it’ll shut off if the voltage goes below some preset amount which I can’t remember of course the battery goes dead so I have one of those jumper boxes I restart it check engine light is on again again it’s for O2 sensors and the OBD reader give me a strange code and when I try and look it up, it sounds like it’s to a Honda something so I think this is really weird, but I reset all the clear all the codes
Once again, I’m on my merry way periodically the check engine light comes on every time I stop for gas. I see what it is. It’s always the O2 sensor code so I reset it keep going.
When I get back home and make an appointment, take the Jeep in I tell the guy look. I’m getting the O2 sensor codes. Check it out. I need to get them redone.
He calls me and says there’s at least two sets of codes there the big important one are the O2 sensors and those are on backorder. Then he says there’s some other electronic module codes which I’m thinking is that one strange code I got when I was camping.

dealer has the jeep for nine days. You finally told me it’s done I go get it and he said they replaced all the O2 sensors under warranty. I asked him about the other codes, the electronic module monitoring codes that he mentioned he said oh those are gone. He thought it was maybe a byproduct of the O2 being bad or something. I’m thinking I don’t know if that sounds right but I want my jeep back cause I’m tired of driving my wife’s car and an a Rent-A-Car and I got work to do and I want my Jeep.
Have a Jeep for maybe three days and I get a P058A code I look it up. Doesn’t seem like a big deal so I reset it thinking OK maybe this is some sort of lingering effect or something. I don’t know. I drive it for another three or four days. Same code comes back this time. I think all right I better take it in and get it straightened out cause I don’t want issues down the line so I take it in and right before I’m taking it in the day before literally the code the check engine light disappears. I still think I’m taking it in just to be sure I take it in and that’s when he tells me it’s a battery monitoring, module or a loose ground wire he says it’s a loose ground wire after looking at the auxiliary wires that are grounded to the ground screws on the right side of the engine bay and I tighten those babies down because When I do do something I’m pretty anal about it. I don’t like half ass things.
And as I’ve been thinking about all of this I came to the conclusion that this is a leftover code from the initial series of codes that were thrown when I was camping and that they just didn’t fix it
So chronologically that’s how it went. I do not necessarily think that the O2 sensor codes had anything to do with this other P058 a code I think that was me coincidence I hope that clears it up for everybody and I know this is really a lengthy long thing I appreciate everybody’s help on this

 

[mwilk012]

No, again. There is no code “02 sensor”. It may be a “bank 1 sensor 1 heater circuit high” or “B1S2 signal low voltage” or similar. These all have verifiable information specific to the exact nature of the failure.

The battery going dead has nothing to do with an oxygen sensor failing, but it may cause false codes to set, especially communication errors (U codes).

Any number of faults in the engine control module will cause a series of other modules to set DTC’s such as “invalid data received from PCM”. These are nothing to even look at.

You probably (almost certainly) have a loose connection from one or more batteries being replaced or a bad mod. Any extras added on to the PDC or battery terminals? Any dumbssses put grease all over your battery terminals?

 

[Ratbert]

No, again. There is no code “02 sensor”. It may be a “bank 1 sensor 1 heater circuit high” or “B1S2 signal low voltage” or similar. These all have verifiable information specific to the exact nature of the failure.

The battery going dead has nothing to do with an oxygen sensor failing, but it may cause false codes to set, especially communication errors (U codes).

Any number of faults in the engine control module will cause a series of other modules to set DTC’s such as “invalid data received from PCM”. These are nothing to even look at.

You probably (almost certainly) have a loose connection from one or more batteries being replaced or a bad mod. Any extras added on to the PDC or battery terminals? Any dumbssses put grease all over your battery terminals?

Just wanted to say thanks to you and the handful of others that seriously know what the fuck they're talking about that are willing to share their knowledge.

 

[wanderer]

Yeah, I do stand corrected. You’re right. The first codes were for the left bank sensor. But the fixed for it was to replace the oxygen sensors. I think it was a coincidence that a few hours after that code occurred in fact overnight that the battery went dead cause I had a refrigerator hooked up to it, which was supposed to have a battery monitoring element built-in that did not work.
Yeah, when I woke up the next morning, of course the battery was dead. I don’t think it was related to the first set of codes.
And I do suppose also that it is possible that one of the ground wires loosened up as I ran hard for about 60 miles on washboard roads
And finally, thank everybody for offering their wisdom on this issue. Now, if I could just get you guys to talk to the technicians at the dealer.

 

[Valpo Jeep]

Typically to have all the O2 sensors go gad at the same time is a mechanical / electrical anomaly. Replacing all 4 is a dealer saying they do not know what is actually wrong so let’s replace all of them as a long shot and see what happens. They then falsely think they actually fixed it.

Sounds like you added lights a year ago and the presumption is all is good with that since it’s running fine since? That is not always correct in reality. It’s entirely possible that a connector has worked its way loose and it’s incorrect to assume all is good. Have to go back over everything. Check the fuse panels as well and make sure everything is seated correctly.

December 2024 I put a new battery in my car and all was good until May 2025 when it started acting like a dead battery. A connection was loose. The new battery terminal was slightly undersized so the negative clamp when fully tightened was actually still loose. How it worked for 5 months is beyond me me. $5 for a battery terminal shim and all is good now.

Stuff worked its way loose.

You may just have to bite the bullet and take it to an independent shop and pay for a diagnosis. Indie shops tend to be significantly better than dealer service departments. They have seen it all on many platforms and can draw on that knowledge and skills for better diagnostics.

 

[UTME]

knock on wood mine has been off since the last time they fixed it 7800 miles ago..did you see this tsb that I posted in your other thread...

That TSB is only for manual transmission, correct?

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