Low Voltage Issue on the 2.0L - Turbo Boost Lag

[Zandcwhite]

I'll just say that there's a reason Jeep engineers did not design the hood with huge holes directly over the electronics in the engine compartment and it wasn't to keep dust off the engine cover.

This discussion is literally decades old. Back in the xj days with their marginal at best cooling systems needed all the help they could get. Some guys had the same mentality you do, the factory engineering is perfect and can’t possibly be improved on. Others like myself went for hood louvers. 10 plus years, parked outside, sometimes for weeks or even months at a time. Not a single sensor failure or other water related issue. There are countless videos of Jeep’s hood deep in river crossings, but I’m sure those rain drops will kill it?

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[legacy_etu]

I'll just say that there's a reason Jeep engineers did not design the hood with huge holes directly over the electronics in the engine compartment and it wasn't to keep dust off the engine cover.

Don't underestimate other internal dynamics going on between the Bean counters/Marketing/ and R&D groups as to what gets put into a product or not. As an Engineer myself there's plenty of times where what you want conflicts with the bean counters or Marketing . Sometimes R&D loses .

I'll also add that way back in the day my Dad handed me down his 1985 Chrysler Lebaron GTS turbo. It came from the factory with a louvered turbo vent directly over the turbo/engine. That car ran flawless for 200K miles. So I'd say that it wouldn't appear that a louvered vented hood is an automatic recipe for disaster.

 

[legacy_etu]

If you have a Rubicon you simply remove the fake vents, cut the under hood insulation and bolt in the real vents. Totally reversible

Ah, that’s right. I forgot the Rubicon’s have that fake vent already.

on a side note: car manufacturers do wrap batteries (usually) with a lightweight “blanket” for insulation purposes I suppose. I always figured they were for protection from the cold….but perhaps they also are intended to help protect the battery from heat.

 

[Zandcwhite]

Just got back from 5 days of wheeling in telluride and Moab. We experienced the low voltage issue for a 2nd time, nearly a year apart. Going up engineer pass, shortly before the Poughkeepsie gulch turn off the engine died , cel came on, and voltage was reading 9.8v. Started it up and pulled off the trail for a 15-20 minute break. Watching the volt meter for the rest of the trip I think we figured out how to beat the system. In 4 high you can drive as normal and the voltage never drops. In 4 low, it’s fine so long as you are moving or in park. Any time we stopped while in drive, the voltage began to drop. It is shit that Jeep hasn’t figured this out, and fixed the tune in years of people having this issue, but at least we seem to have a working solution. By putting it in park any time we stopped even for a short time, we were able to wheel for 3 more days at both higher elevations and significantly higher temperatures without issue. In my opinion it’s a combination of the torque limiting in 4 low, the thin air at elevation, the heat, and the stopping somewhat under load simply not producing enough power through the bsg to keep up. On the bright side, it has convinced the wife to try the super chips tune eliminating the torque limiting, and who doesn’t love when power upgrades are endorsed by the wife?

 

[ColoradoB]

Do you think replacing the main car battery with an Optima Red Top or the like would fix this issue or do we all think it's directly related to the 40v hybrid mess?

 

[Zandcwhite]

Do you think replacing the main car battery with an Optima Red Top or the like would fix this issue or do we all think it's directly related to the 40v hybrid mess?

I think it's the hybrid system, bsg output, or 40v dc to 12v dc inverter. Being it seems rpm/ load related my money is on the bsg itself.

 

[JLU138]

I think it's the hybrid system, bsg output, or 40v dc to 12v dc inverter. Being it seems rpm/ load related my money is on the bsg itself.
[/QUOTE
Agree Completely. i have the hybrid ( REGRET). i did replace the battery with an Optima. No difference. All indicators after 2 years point to the hybrid electric system somewhere. And it’s 100% load related. The lower the PSI in my 37s, the more often and catastrophic the failure. I’ve just accepted that i can’t go below 20 psi, and that i’ll have to completely turn off the vehicle a few times per day on the trail

 

[Zandcwhite]

Have you had the issue in 4 hi? We wheeled for multiple days both at altitude in telluride and in the heat in moab at 15 psi in our 37's in 4 high and never had an issue. I think it's 4 lo torque limiting reducing the output that is just too much for the bsg to keep up with?

 

[AnnDee4444]

Have you had the issue in 4 hi? We wheeled for multiple days both at altitude in telluride and in the heat in moab at 15 psi in our 37's in 4 high and never had an issue. I think it's 4 lo torque limiting reducing the output that is just too much for the bsg to keep up with?

I would expect the BSG to have an easier time with the load in 4-low. Can you explain what you mean by the BSG can't keep up?

It could also be the battery overheating. In 4-low your speeds would typically be less than 4-high, meaning less airflow over the radiators.

 

[Zandcwhite]

I would expect the BSG to have an easier time with the load in 4-low. Can you explain what you mean by the BSG can't keep up?

It could also be the battery overheating. In 4-low your speeds would typically be less than 4-high, meaning less airflow over the radiators.

It seems like the issue happens at low speed, in 4 lo, but doesn't happen at the same speeds in 4 hi. After it happened on poughkeepsie Gulch, I started paying way more attention to the battery voltage. It would start falling immediately any time we stopped in drive, in 4 lo. Put it in park and it stabilized instantly. We wheeled 2 days in moab the same week, but intentionally kept it in 4 hi. No falling voltage, even when stopped in gear, in 104⁰ weather. It appears to be a programming issue, and knowing that the torque is limited by the ecu in 4 lo, I think it's just a bad combination. My next step in testing my theory is getting an unlocked ecm and a tune that eliminates the 4Lo torque limiting. If that works, it's a simple enough fix.

 

[JLU138]

Have you had the issue in 4 hi? We wheeled for multiple days both at altitude in telluride and in the heat in moab at 15 psi in our 37's in 4 high and never had an issue. I think it's 4 lo torque limiting reducing the output that is just too much for the bsg to keep up with?

I don’t do a lot of rock crawling in 4 high, so I don’t know if there’s a difference. I am definitely going to try that though the next couple of times. but no, I’ve never had a problem in 4 high. It’s always 4 low at low speeds.

 

[BLACKJACKcn]

My 2019 jeep wangler jl 2.0t 48v system is broken,After the battery warning sign turns red, the voltage continues to drop from 12.8 to 6.8, and then the vehicle loses power.

because my car is not in the United States, so I can’t get warranty service. What’s worse is that bpcm parts jeep cannot be purchased personally, mopar said part no.68381513AA is a limitation on this part. It will not be sold by any dealer in the US unless the car is physically driven in for service.

So I disassembled the BPCM and battery, I see that the chip on the bpcm dcdc controller is burned ，the voltage of the lithium battery pack in the box above bpcm is 44v（It may be that it has not been charged for a long time, and the voltage has dropped）

 

[oldcjguy]

My 2019 jeep wangler jl 2.0t 48v system is broken,After the battery warning sign turns red, the voltage continues to drop from 12.8 to 6.8, and then the vehicle loses power.

because my car is not in the United States, so I can’t get warranty service. What’s worse is that bpcm parts jeep cannot be purchased personally, mopar said part no.68381513AA is a limitation on this part. It will not be sold by any dealer in the US unless the car is physically driven in for service.

So I disassembled the BPCM and battery, I see that the chip on the bpcm dcdc controller is burned ，the voltage of the lithium battery pack in the box above bpcm is 44v（It may be that it has not been charged for a long time, and the voltage has dropped）

Appears to be available from online resellers.
2018-2021 Jeep Wrangler Power Pack Unit Battery Kit 68381513AA | Mopar Estores

 

[BLACKJACKcn]

Appears to be available from online resellers.
2018-2021 Jeep Wrangler Power Pack Unit Battery Kit 68381513AA | Mopar Estores

my ordering be canceled，i don't know why.

 

[oldcjguy]

my ordering be canceled，i don't know why.

It's available from other sites as well. I'd call them and find out why it was cancelled. May be just a complication from an out of country order. Maybe overseas charge was cancelled. I'd give them a call

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