Just fixed a Cummins ISX that had me stumped for 3 days straight

I had this 2015 Freightliner with an ISX that kept throwing a cam sensor code but the sensor was fine. I swapped the sensor, checked the wiring, even replaced the ECM and nothing worked. After 3 full days of pulling my hair out I finally found the issue. The tone ring on the cam gear had a tiny crack that only showed up when the engine got hot and expanded. Cost me about $400 in parts I didn't need and 20 hours of labor before I caught it. Has anyone else run into a phantom code that drove them crazy like this?

2 comments

2 Comments

wyatt1351d ago

Man that tone ring crack is brutal. I had a similar nightmare with a 3126 where the crank position sensor would glitch out on hot days only, took me two weeks to realize the damn reluctor wheel had a hairline fracture that expanded when it got warm. Three sensors, a harness, and a whole ECM later...

phoenix5731d ago

Buddy of mine had an ISX in a Kenworth that ate two crank sensors before he figured out the flexplate was warped just barely enough to scrape the sensor on cold starts. He replaced the whole flexplate and never saw the code again. $1,200 later and he still swears that truck was haunted.