By Russ and Tiña De Maris
While the shortage of microchips has turned auto manufacturing upside down, RVers, too have been hit. If you’ve been following our coverage about how so many RVers have been stranded by DEF (diesel exhaust fluid) sensor failures, you know we’ve been harping on industry to come up with at least a temporary fix. We wrote early this month that Cummins, the EPA, and other industry types had announced they would allow a software patch. That patch would allow affected rigs to get back on the road, even before microchips could “ride to the rescue.” At the time, we wondered how long it would take for the software patch to materialize.
It seems the answer is – nearly a month. But we’re happy to report that Cummins is now issuing the temporary fix to “eligible” Cummins engine owners. Here’s how it works.
First, you have to qualify
Cummins, other industry interests, and the EPA have agreed on what they’re calling “a temporary calibration” to be loaded into Cummins’ engine control systems. We say “eligible” engine owners, because not everyone with a Cummins engine under the hood will be able to get the software patch. How do you know if you qualify?
First, your vehicle must already be disabled, that is, with the DEF system warning light showing up on your dashboard. If you’ve been hiding at home in the driveway, fearing to take your motorhome out on a trip lest it break down, hear this: If your DEF light isn’t illuminated, you don’t qualify for the patch.
Another condition may also rule out the software patch. Not all DEF sensor manufacturers are “fresh out” of DEF sensors. Cummins will NOT be able to provide the software patch UNLESS the DEF head in your rig is one that can just be readily replaced because of a shortage. How do you know where you stand? Here’s the official word from Cummins: “We encourage [owners] to inquire by emailing email@example.com and include their engine serial numbers when emailing. For those OEMs that are not currently participating, we encourage customers to reach out to their vehicle manufacturer to secure a DEF sensor replacement because Cummins is not permitted to provide the calibration fix.”
A couple of hoops to go through
Here are some “ifs.” If your DEF system is already displaying an error message, and if your DEF head manufacturer can’t supply a replacement, then you can probably get the software patch. How do you do it? Ensure that you’re on the “OK list” by sending off an email to Cummins. Next, schedule an appointment with a service facility. Cummins has provided an internet link to a system where you can locate facilities anywhere in the U.S.
How much will it cost you? To Cummins’ credit, the software patch installation is a freebie. We’re hopeful that the lineup to get in and get the job done will be short, and hopefully painless. Once the patch is in place, the engine de-rate that has grounded so many will go away. Be alert though. You’ll have to manually check your DEF levels, as you won’t get any warning that you’re low on DEF. If you run your rig without DEF, you’ll soon be de-rated and in a world of hurt.
California “fly in the ointment”?
There is one more possible “fly in the ointment.” Here’s a quote from an email from Cummins to a reader. “Once the supply of DEF sensors becomes available, you will be contacted and required to make a service appointment to replace the DEF sensor and restore the original engine calibration. Please note, once the replacement parts are available, the repairs must be completed as the vehicle cannot be operated in the state of California without the original engine calibration.”
Let’s read that r-e-a-l s-l-o-w. “The vehicle cannot be operated in the state of California without the original engine calibration.” It was too late in the news cycle for us to clarify this statement. Has California not signed up for this software patch? Does it mean those who do get the software patch best stay out of California until they have a new DEF sensor? Meaning they’d be violating the law? We’re not entirely clear on this, but we’ll update you once we know for sure.
And for those who may not qualify
What about those of you who haven’t received the dreaded DEF sensor of death dashboard denunciation. Fearful of leaving the yard, lest you de-rate your diesel and end up in the ditch? We’ll point you back to the alternative DEF Sensor Simulator. If you build one, keep it with you. If your warning light comes on, plug it in. You can then go merrily on your way until you can get the software patch.
We’re happy that Cummins has stepped up to the plate with the software patch. But we’re still of this mind: The reason they did so is that the RV community kept after them to get off the dime. There is power in your words.
Edit note: Included working link to Cummins locator service. 9/26/21 1048hrs