Complete engine shutdown while at a red light. Car doesn't start. No crank/power. power control recall?

[hexeis]

Hi all

Thought I'd post here in hopes of finding someone who might help me. Here are some details on my car:

2019 JL Sahara
60.5k miles
Both batteries are less than 12 months old.

I was driving to work. Was at a red light. When the light turned green I let go of the brake to press the gas. Suddenly the car just shutdown completely - engine off and complete dash off. I tried pressing the brake and pressing the start button but it wouldn't crank at all. Dashboard, lights, and accessories starting coming back online. I then shut if off. and disconnected the negative terminal on the battery for 10 minutes. Reconnected and still have the same issue. Had to get it towed...

I towed it to the dealer and had a miserable experience. I arrived on a Friday morning and it took them 6 days to take any action. They wanted to change the fuse array and charge $100 for parts and $225 for labor. This was before conducting the diagnostic. I have an extended warranty but apparently it didnt' cover the fuse array. I was upset because I've changed the fuse array myself before. It costs me $80 and 20 minutes. After such terrible communication from my service agent, his manager, and then the exorbitant labor costs, i told them not to do any work and that i would have my car towed to a friendly mechanic that I knew. Before I left i walked over to their parts department and bought the fuse array for $80 and swapped it myself at my mechanic after 20 minutes. Car has the same issues. It won't crank.

My mechanic says he can start the engine after bypassing the fuse box and was going to suggest replacing teh fuse box. However, he says he has an app that suggest that the power control module on my vehicle appears to be recalled. He mentioned that if this is the case, that I should contact a dealer to confirm and have them fix that before he lays his hands on replacing the fuse box. Has anyone heard of this? I haven't not heard of this being recalled. Any help or suggestion is greatly appreciated.

TY

Sponsored

 

[alphawolff]

When that fuse blows your aux battery will also die. Pull both battery terminals off the primary and charge the aux through them. Your jeep will not start until it is recharged. It is possible it may need replacing depending on the health of the battery. Being under a year old you may be fine. You can get it started in the meantime by jumping the #3 PDC stud with a jump box.


The dealer would've most likely done this free of charge after replacing your z-case fuse which is a very common failure point. I personally did this exact repair today on a gladiator who also died in the exact same way yours did. I charged one hour of labor which included diagnostic, the fuse replacement, and the recharge.

The $225 of labor was a very fair price in this market. It isn't 2005 anymore. You're paying for their expertise. Now you've paid for two tows and someone else who doesn't know what they're doing suggesting you throw random parts at it without any proper diagnostic.

 

[hexeis]

Pull both battery terminals off the primary and charge the aux through them. Your jeep will not start until it is recharged. It is possible it may need replacing depending on the health of the battery. Being under a year old you may be fine. You can get it started in the meantime by jumping the #3 PDC stud with a jump box.

Pardon my ignorance, but I did not understand this. Once disconnecting the primary, how do I charge the aux?

You also said the Jeep won't start without the aux, but I once ran without an aux. I had F42 fuse removed and the negative cable to the aux disconnected.

What is the #3 PDC stud?

 

[alphawolff]

Pardon my ignorance, but I did not understand this. Once disconnecting the primary, how do I charge the aux?

You also said the Jeep won't start without the aux, but I once ran without an aux. I had F42 fuse removed and the negative cable to the aux disconnected.

What is the #3 PDC stud?

F42 simply prevents the PCR from isolating the aux battery. It forces the them to always stay connected, rather than allowing them to isolate. If all you did for the aux was disconnect the negative terminal then that part in reality had zero effect on vehicle operation because you pulled the F42 fuse. In normal battery deletes the fuse is left installed and a jumper is installed between the N1 and N3 PDC posts. This will prevent any CEL from ever occurring as a bonus if for some reason you intended to still use stop/start. It essentially allows the primary battery to bypass the PCR and supply power to both ends of the circuit. Normally the aux batter is then either totally disconnected or removed from the vehicle.

That being said, the aux is responsible for powering the interior of the vehicle during the first crank attempt (and during stop/start events). If it is too dead this attempt will fail interrupting the process. If the aux had a bit of life left it would've de-energized the PCR on the second crank allowing it to start. When the z-case fuse blows the primary battery is no longer able to power any of the vehicle's interior electronics. As the aux battery is incredibly tiny it isn't designed to power the interior for very long. It also will not charge while the fuse is blown. Eventually it'll either stall out, or in your case, fail to restart at a light. I hope this explains why it is responsible for allowing it to start. I don't know why the fuse fails so much, but it is incredibly common.


The PDC studs are numbered. The one closest to the primary battery is N1. The N3 is the one you would usually put a jumper on to allow a JL with a flat aux batter to crank. If you put a DMM on it, you'd see it probably only has 4-5v or so, if that. Make sure your jumper is in bypass mode, as if it's an automatic model it may not detect enough of a voltage to energize.

As the PCR is usually connected, you're able to effectively pull both primary battery terminals off the main battery and stick a charger onto those leads. As they're connected to the aux battery you can easily charge the aux battery without removing it from the vehicle. You could also put the positive onto the N3 stud, however there's a lot of in between connections so it doesn't charge as well that way.

Essentially - Pull the leads off the primary battery and charge the leads themselves with a battery charger.

There is a very detailed write-up of how our battery systems work on this forum if you're looking for more information on the stop/start system.

 

[Wbino]

Sometimes you have to bite the bullet.

 

[mwilk012]

You should leave your vehicles electrical system stock if you don't plan on being able to always fix it yourself. This whole F42 nonsense has got to go.

F42 simply prevents the PCR from isolating the aux battery. It forces the them to always stay connected, rather than allowing them to isolate. If all you did for the aux was disconnect the negative terminal then that part in reality had zero effect on vehicle operation because you pulled the F42 fuse. In normal battery deletes the fuse is left installed and a jumper is installed between the N1 and N3 PDC posts. This will prevent any CEL from ever occurring as a bonus if for some reason you intended to still use stop/start. It essentially allows the primary battery to bypass the PCR and supply power to both ends of the circuit. Normally the aux batter is then either totally disconnected or removed from the vehicle.

That being said, the aux is responsible for powering the interior of the vehicle during the first crank attempt (and during stop/start events). If it is too dead this attempt will fail interrupting the process. If the aux had a bit of life left it would've de-energized the PCR on the second crank allowing it to start. When the z-case fuse blows the primary battery is no longer able to power any of the vehicle's interior electronics. As the aux battery is incredibly tiny it isn't designed to power the interior for very long. It also will not charge while the fuse is blown. Eventually it'll either stall out, or in your case, fail to restart at a light. I hope this explains why it is responsible for allowing it to start. I don't know why the fuse fails so much, but it is incredibly common.


The PDC studs are numbered. The one closest to the primary battery is N1. The N3 is the one you would usually put a jumper on to allow a JL with a flat aux batter to crank. If you put a DMM on it, you'd see it probably only has 4-5v or so, if that. Make sure your jumper is in bypass mode, as if it's an automatic model it may not detect enough of a voltage to energize.

As the PCR is usually connected, you're able to effectively pull both primary battery terminals off the main battery and stick a charger onto those leads. As they're connected to the aux battery you can easily charge the aux battery without removing it from the vehicle. You could also put the positive onto the N3 stud, however there's a lot of in between connections so it doesn't charge as well that way.

Essentially - Pull the leads off the primary battery and charge the leads themselves with a battery charger.

There is a very detailed write-up of how our battery systems work on this forum if you're looking for more information on the stop/start system.

Bad starters blow fuses.

 

[hexeis]

You should leave your vehicles electrical system stock if you don't plan on being able to always fix it yourself. This whole F42 nonsense has got to go.


Bad starters blow fuses.

So does this mean you think I should replace my starter?

 

[roaniecowpony]

Did you check the fuse array with a meter to see if any of them were blown?

 

[hexeis]

Did you check the fuse array with a meter to see if any of them were blown?

I did. One was blown. As mentioned in my story, I replaced the fuse array.

 

[Jebiruph]

You should leave your vehicles electrical system stock if you don't plan on being able to always fix it yourself. This whole F42 nonsense has got to go.


Bad starters blow fuses.

I'm not so sure about a bad starter blowing the 150A N3 fuse which is the one we are talking about here. Do you think a bad starter that's connected directly to the main battery is going to draw over 150A from the aux battery in order to blow that fuse? How many hundreds of amps would that starter be drawing from the main battery at the same time?

 

[mwilk012]

I'm not so sure about a bad starter blowing the 150A N3 fuse which is the one we are talking about here. Do you think a bad starter that's connected directly to the main battery is going to draw over 150A from the aux battery in order to blow that fuse? How many hundreds of amps would that starter be drawing from the main battery at the same time?

580 to be exact

 

[alphawolff]

Bad starters blow fuses.

That's the thing, though. While this is a totally plausible cause of the condition (The engine crank blows the fuse during a S/S event) it brings the question as to why they never come back after the fuse has been replaced.

Are the original batch of fuses faulty? Or were they working as designed and the newly installed batch is faulty and doesn't blow? Totally random quality control perhaps? Hard to say.


I say this as I've had another one towed into the shop today for the same issue. It's incredibly common issue and I wonder why there hasn't been some type of recall on it.

So does this mean you think I should replace my starter?

No. Replace or charge the aux battery and go about your day.

 

[Jebiruph]

If the engine crank is blowing the fuse during a S/S event, It's not because of a bad starter or bad aux battery, it's due to a bad or under charged main battery.

During a S/S event, some amount of electrical energy is present in the system electronics. When the S/S event ends, the PCR reconnects the aux battery powered systems with the main battery powered systems at the same time power is needed to start the engine. If the main battery output is too low, it will cause the combination the aux battery power plus the energy stored in the system electronics to surge through and blow the N3 fuse.

That's why the S/S system gets disabled when the main battery is charging and it's the IBS that monitors the status of the main battery. So if the main battery isn't up to the task and S/S isn't disabled resulting in a blown N3 fuse, blame the IBS.

I don't know how often a surge is legitimately blamed for a blown N3 fuse. Between the jlwrangler and jeepgladiator forums , I only remember seeing one confirmed surge blown fuse incident reported. Usually a blown N3 fuse coincides with a recent positive battery cable disconnect.

 

[mwilk012]

That's the thing, though. While this is a totally plausible cause of the condition (The engine crank blows the fuse during a S/S event) it brings the question as to why they never come back after the fuse has been replaced.

Are the original batch of fuses faulty? Or were they working as designed and the newly installed batch is faulty and doesn't blow? Totally random quality control perhaps? Hard to say.


I say this as I've had another one towed into the shop today for the same issue. It's incredibly common issue and I wonder why there hasn't been some type of recall on it.




No. Replace or charge the aux battery and go about your day.

The part that you don't see is the owner/wrecker driver/buddy-neighbor fucking with it causing the blown fuse.

Sponsored