Dreaded engine light..

[zouch]

might be worth pulling the batts out to take a look at them; fortunately in the diesels, it's really easy to do. maybe even have them both tested, and/or charge/condition them, and/or replace them outright so you know their history and see if you still have codes.

voltage is seen to vary with these things; anywhere from mid 11s to 14s, depending on a variety of factors. gotta' remember the indicated voltage is some summary based on the combination of the 2 batts.

have you tried looking at the indicated voltage before you start it up when it's been sitting for a while?

I'm unsure, purchased this used. It's a 2020.
Battery voltage is a little low, but no issues starting. Offroad pages shows it at 12.7 when on.

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[mwilk012]

None of these faults are low voltage related.

 

[zouch]

perhaps; yet we've all seen faults that are not voltage related come and go relative to poor batteries.

None of these faults are low voltage related.

 

[Pape]

when voltage is outside of the operating spec for the module, do not be surprised to get garbage out. The resulting code is all on how the error are interpreted. I suspect a lot of binary result, It work or it does not. Except for U0415 who look to have a more elaborated error control as it say it is outside of it table.

 

[mwilk012]

perhaps; yet we've all seen faults that are not voltage related come and go relative to poor batteries.

Trust me I do this every day. The long string of codes set by low battery voltage will always include “low voltage” in at least one module.

 

[Deleted User 38384]

a low battery as other have stated.

Ahh, shucks! You beat me too it!

2020 3.0

How long ago did you purchase your Wrangler?
How many miles are on it when you purchased it?
How many miles are on it right now?

 

[hilljumper]

So, light came on.
I checked the codes with tazer.
Seems like ABS is having issues.

U0415
U0100
B16B7-15
C1514-87

How would I fix these issues?

do you have the shop manual?

 

[zouch]

sounds very reasonable, but in my admittedly limited experience, i have already seen that to not necessarily be true. i wish it were that easy!

the codes reported by these things are so random.
i once had a string of almost a dozen codes that reported problems including turn signals to O2 sensors to Mass Air Flow rate discrepancies to Fuel Reductant Pressure and Fuel Temps being out of bounds,.. all at the same time.
the closest i got to anything remotely Voltage related was one that was defined as "O2 Sensor 2/1 Pumping Overcurrent".

all 11 (eleven!) codes went away with a fresh set of batteries and have not come back in several thousands of miles of operation.

if that one P112D-00 was supposed to be a indication that the batts were tired, that's a pretty damn obtuse way of indicating it.

Trust me I do this every day. The long string of codes set by low battery voltage will always include “low voltage” in at least one module.

 

[mwilk012]

sounds very reasonable, but in my admittedly limited experience, i have already seen that to not necessarily be true. i wish it were that easy!

the codes reported by these things are so random.
i once had a string of almost a dozen codes that reported problems including turn signals to O2 sensors to Mass Air Flow rate discrepancies to Fuel Reductant Pressure and Fuel Temps being out of bounds,.. all at the same time.
the closest i got to anything remotely Voltage related was one that was defined as "O2 Sensor 2/1 Pumping Overcurrent".

all 11 (eleven!) codes went away with a fresh set of batteries and have not come back in several thousands of miles of operation.

if that one P112D-00 was supposed to be a indication that the batts were tired, that's a pretty damn obtuse way of indicating it.

11 codes is just one module. I’m talking about scanning ALL modules for all faults. The answer is usually very clear.

This forum is absolutely fucking obsessed with batteries like it’s the answer to everything. It’s been this way for 7+ years.

 

[zouch]

sorry if it wasn't clear, but in my case, it doesn't seem like all 11 codes were from the same module. (i have a couple of different ways to scan, but wouldn't intentionally ever scan just one module.)

i don't know about "obsessed", but batts in these things fail early and frequently; that doesn't help take them off the suspect list.
moreover, since all the codes went away when just replacing the batts, it doesn't seem like a reach to suspect that implies it was something related to the batts, does it?

11 codes is just one module. I’m talking about scanning ALL modules for all faults. The answer is usually very clear.

This forum is absolutely fucking obsessed with batteries like it’s the answer to everything. It’s been this way for 7+ years.

 

[mwilk012]

sorry if it wasn't clear, but in my case, it doesn't seem like all 11 codes were from the same module. (i have a couple of different ways to scan, but wouldn't intentionally ever scan just one module.)

i don't know about "obsessed", but batts in these things fail early and frequently; that doesn't help take them off the suspect list.
moreover, since all the codes went away when just replacing the batts, it doesn't seem like a reach to suspect that implies it was something related to the batts, does it?

Replacing both batteries will clear all codes as memory is lost.

 

[alphawolff]

You need the rest of the codes. What @mwilk012 said is correct. Unless you scan everything you're just wasting time and effort here. Based off the codes provided the ABS module will have your code. If the tazer doesn't read it then get another scanner, or have the dealership scan it

 

[JINO]

do you have the shop manual?

Sorry, I'm not sure what a shop manual is.

 

[JINO]

Ahh, shucks! You beat me too it!


How long ago did you purchase your Wrangler?
How many miles are on it when you purchased it?
How many miles are on it right now?

Purchased 1 year ago.
45k
It's now 90k.

Will be replacing battery soon.

 

[zouch]

as already reported, tests were done with a regular scanner (not just a Tazer). nothing as fancy as i’d hope a dealer might have, just a mid-grade FLAPS USB II handheld unit.

i’d expect codes would go away after a power disconnect, but i’d also expect that they would have come back in the thousands of miles driven in the year+ since that incident if they’d have been valid.
if a Low Voltage issue were to have been the cause of all those DTCs and only have been diagnoseable via a non-Voltage related code in the ABS module, that seems pretty wonky (on the Designers part). but i guess we shouldn’t put it out of the realm of possibility considering all the other weirdnesses we’ve seen with these things.

Replacing both batteries will clear all codes as memory is lost.

You need the rest of the codes. What @mwilk012 said is correct. Unless you scan everything you're just wasting time and effort here. Based off the codes provided the ABS module will have your code. If the tazer doesn't read it then get another scanner, or have the dealership scan it

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