I wish I could tell you I had any idea what the heck I was doing when I started engineering the Jeep Wrangler JL’s cooling system back in 2013. But I was 22 years old, the company had just risen from the DaimlerChrysler ashes thanks to Fiat, and the new Sergio Marchionne-led “Fiat Chrysler” was on a hiring offensive because it needed bodies to replace the ones who took buyouts. I was one of those bodies, and boy was I thrown into the deep end.
As an enthusiastic recent engineering graduate who had wanted to work for Chrysler his entire life, I was welcomed into the Advanced AeroThermal team and assigned the Systems Integration Responsible for any program I wanted. The rest of my team didn’t seem to care what car they worked on — something that blew my mind since I assumed everyone working for a car company was an enthusiast — so I jumped on the Wrangler and Viper (the latter program of which was terminated).
AeroThermal was a group that encompassed all thermal and aerodynamic design, since the two are so related, especially in the area of powertrain cool. That’s what my primary focus was: Make sure the 2.0-liter turbo inline-four, 3.6-liter naturally aspirated V6, and 3.0-liter turbodiesel could handle Davis Dam and our other barrage of challenging on and off drive cycles without overheating.
I had to make sure transmissions weren’t burning up, that exhaust components weren’t posing any sort of fire risk, and my most difficult task was handling cooling system design for all of the company’s mild hybrid systems. The systems were being developed my Magnetti Marelli and Samsung. I worked with them to develop the cooling system for the under-rear-seat-mounted lithium ion battery pack, and I had to make sure the air and liquid cooled MGUs (basically, the big motor/generator that replaces the alternator) wouldn’t overheat in the Wrangler’s and Gladiator’s harshest driving cycles.
What’s crazy about all of this is that, while I was learning about cooling system design, I was also being tasked with writing the standard processes for powertrain cooling. Yes, you read that right; a new-hire wasn’t learning from the standard-process documents, he was creating them. Those were some very strange times, and definitely a transition period for Chrysler.
Even years after I left Chrysler I’d find myself waking up in a sweat, grabbing my laptop, and searching for other hybrid battery systems that were purely passively liquid-cooled like the JL I had designed (there was a thermoelectric device built into the packs, too). There wasn’t much out there, and in general, when that’s the case, I like to wonder why the hell we were doing something different than the rest. But I’d made sure our derate strategy made sense, so even if the cells did get too hot in certain conditions, the contactors would open and all would be safe.
Anyway, this is a weirdly long run-up to say: When my colleague Matt sent me a Detroit News story about 1 million Jeep Wranglers being recalled due to fire risk, a shot of adrenaline surged through my body. I was relieved to learn that the vehicles —787,887 2021 to 2025 Jeep Wrangler “JLs” and 289,112 2021 to 2025 Jeep Gladiator “JTs” — were being recalled for an electrical fault and nothing powertrain related.
[Ed note: Oops. DT has been up all night working on the Rivian review and I jokingly said “Is this your fault” in Slack knowing that it probably wasn’t based on the description. Maybe a poorly-timed joke. Sorry DT! – MH]
In fact, it’s not just a recall, it’s a “Park Outside” notification telling owners of affected vehicles to stay away from buildings, lest the Jeep fire cause a building fire. From NHTSA:
Some 2021-2025MY Jeep Wrangler vehicles may have an Electric Hydraulic Power Steering Pump (“EHPSP”) electrical connection susceptible to high resistance.
The suspect vehicle population began on June 24, 2020, when production of Jeep Wrangler vehicles with suspect EHPSP electrical connections began, and concluded on December 2, 2024, when suspect vehicle production ended. The suspect period was determined using vehicle production records. Similar vehicles not included in this recall were built before or after the suspect vehicle production range.
The same recall applies to Gladiators; from NHTSA:
Some 2021-2025MY Jeep Gladiator vehicles may have an EHPSP electrical connection susceptible to high resistance. The suspect vehicle population began on August 18, 2020, when production of Jeep Gladiator vehicles with suspect EHPSP electrical connections began, and concluded on December 2, 2024, when suspect vehicle production ended. The suspect period was determined using vehicle production records. Similar vehicles not included in this recall were built before or after the suspect vehicle production range.
This is not good, with the June 4, 2026 Recall Report reading:
In some circumstances, high resistance electrical activity may take place in the area of the EHPSP connection causing overheating of combustible materials.
Overheating of combustible materials in the vehicle or surrounding area may potentially lead to a fire. A fire can result in increased risk of occupant injury and injury to persons outside the vehicle.
The part in question is the Eletro-Hydraulic power steering system. I was in the “Chunk Team” meeting when the chief engineer decided to add this to the program. There were really only two power steering options since an electric power steering rack wasn’t going to package with a solid axle and since the team had decided to keep the old-school worm-gear style steering box.
One option was a column-mounted power steering unit, and the other involved keeping the hydraulic assist everyone was used to, but the hydraulic fluid would be pumped not by the engine’s accessory drive but by an electric motor driven by the Jeep’s 12-volt battery. Engineers chose to go with the later electrohydraulic power steering system for reasons I cannot remember — a system that could still offer benefits including reducing the parasitic draw when the driver wasn’t applying steering input (a traditional system would spin the pump impeller anytime the engine was on).
Anyway, something is going on with the wiring of these electrohydraulic power steering pumps, and it can happen even when the car is off, as NHTSA writes:
The electric hydraulic power steering pump wiring may overheat and cause a vehicle fire, even when the vehicle is parked with the ignition in the “Off” position
Dealers will replace faulty parts, but until then, Stellantis and NHTSA advise owners of these Jeeps to stay parked away from buildings. Per NHTSA:
Owners are advised to park outside and away from structures, until their vehicle is repaired. Dealers will inspect and replace affected parts, as necessary, free of charge.
As relieved as I am that I wasn’t the cause of this, I am bummed for the owners of these 1 million Jeeps — owners who now have to stay out of parking structures and personal garages.
Top Image: Jeep
I’d love to read this but the nonstop moving ads make that not possible.
Interesting when you can keep your extra hydrazine in the garage, but not your battery car.
Geez, I just got back from a road trip on mine. Looks like they’re releasing the VIN list on June 11th.
There had to be some change between the steering units David was exposed to and those being red flagged. I believe the first JLs were mid-2018 MY, but the advisory is for 2021-25 MY.
I’d really like to know more details about what exactly the fault is and how it can happen even when the vehicle is off? It sucks for owners but at least it’s going to get fixed.
It seems to me that the recalls across most manufacturers have been steadily climbing over the last few years. Is it just me that feels this or is it a trend?
Stuff getting ever more complicated.
Maybe they should toss the gee wiz stuff and stick with getting their production sorted, then get fancy? Just a thought. I come from a software development background and it seems that they’ve letting feature creep dominate their processes and overwhelm them.
You typically never want “Overheating of combustible materials”. Jeep: Now the regular ones catch fire too! It’s not just the PHEV’s.
They got tired of the 4XE owners having all the fun!
What kind of person continues to worship at the altar of this dumpster fire?
Jeep people just seem to be suckers for punishment.
Agreed. 8 years with my 4Runner, and I once got a warning message about the transmission running hot. I wouldn’t trade it for a Jeep if you paid me the Jeep’s asking price in addition to giving me the vehicle.
What year is the 4Runner?
Kind of like VW people. There’s a draw that is irresistible (I assume for Jeep people) and overrides logical thinking. Yes, I am a recovering VW person.
I’ve said this before and I’ll say it again. Some (not all) of the water-cooled VWs I’ve owned and worked on over the years have had more than their share of quality control issues and recalls. Irritating, yes. But none of them could result in a fire while the car was off and parked. Not that I would buy anything VW currently sells in the States these days.
I swear VW sends the shitty ones to North America and keeps the reliable ones in Europe. I’ve owned veedubs for years and never had serious problems, ditto the rest of my family (who have branched out into Skodas because they’re cheaper, but still as reliable)
There’s a woman in my apartment complex who drives a wrangler 4xe, and she always parks it in the garage. I wonder if she knows about these issues.
It’s not like most people park in their garages anyhow. Those seem to be junk storage units for a lot of people.
That’s not junk in there! Those are my other cars which are… well, okay, point taken.
My 2 car garage has 2 cars in it. The problem is, we have 4 cars.
My 2 car garage has 5 vehicles in it, thank you very much. 3 of them even work!
…Maybe you have a point, actually.
I used to live in the suburbs and people were parking their $50k cars outside so they could store about $75 worth of junk in the garage.
Our neighbors have a lifted Toyota Tundra and a brand new Highlander XSE sitting outside while their 2-car garage is full of cardboard boxes. Meanwhile, my 2-car garage houses a 2016 Mazda6 and a 1990 Pontiac freakin’ Sunbird. We are not the same type of people at all…
Living in a European capital, I wonder how would I comply with the park outside mandate…
You could ask the company that question in writing?
Might move you up the list.