Intermittent U0016 on Freightliner Cascadia - Dash Flickering then Dead

Question

I am getting a recurring U0016 fault code on my 2018 Cascadia and the dash keeps dropping out while I am under load. Sometimes the gauges just freeze up or the lights flicker, and then the truck won't respond to the diagnostic tool until I cycle the master switch. It seems like a communication bus short because the cab controller is throwing a fit.

road_rambler · Accepted Answer

Found the problem and it's fixed. There was a rub-through in the MS-CAN harness behind the dash panel near the passenger-side cup holder assembly. The green wire (CAN Low) was chafed and grounding out against the dash support frame. I cut out the bad section, soldered in a new 3-inch pigtail of twisted pair 18AWG, and wrapped it in Tesa tape. Resistance across pins 6 and 14 is back to a solid 60 ohms and the u0016 has not returned after a 200-mile test run.

Luis Hernandez · Answer

Look at the wiring harness specifically where it passes through the steering column or behind the radio. The MS-CAN often rubs against the metal brackets and shorts the negative side to the chassis.

obd2_owl · Answer

Check the terminating resistors on the CAN bus backbone. If one of those is going bad or has high resistance, you'll get reflection on the line that causes that U0016 low voltage reading.

shoptech_carlos · Answer

I had a similar issue on a 125SD. It turned out to be the bulkhead connector on the firewall. Moisture gets in there and creates a bridge between the CAN Low pins and ground, which triggers the U0016 code immediately.

Intermittent U0016 on Freightliner Cascadia - Dash Flickering then Dead

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