Watch out for that new 'universal' DEF heater kit

I put one on a 2017 Freightliner Cascadia last week, the kind that says it fits any truck from 2010 up. It worked fine for two days, then threw a constant SCR fault and derated the engine. Turns out the heater's pulse signal was just a hair off from what the truck's computer expected. I had to swap it out for the OEM part to clear the code. Has anyone else run into this with aftermarket DEF system parts?

2 comments

2 Comments

viola_patel721mo ago

Yeah, the wiring harness length can mess with the signal too. Had one where the extra slack acted like an antenna and picked up noise.

wren3071mo ago

That's a classic EMI issue. Proper cable management is key to avoid those problems. Zip ties are your friend for a reason.