Case Study: F-350 with multiple warning lamps on, multiple U-codes set

Aug. 22, 2023

The driver of this snowplow Ford F-350 complained that multiple warning lamps were on, such as the brake light, ABS and malfunction indicator light (MIL).

Richard Diegle

Related To: ALLDATA

Vehicle: 2017 Ford F-350, 4WD, Super Duty, V8-6.2L, automatic transmission/transaxle

Mileage: 135,562

Problem: The driver of this snowplow Ford F-350 complained that multiple warning lamps were on, such as the brake light, ABS and malfunction indicator light (MIL).

Case details: The tech scanned for diagnostic trouble codes (DTCs) and found the following codes:

U0100:00 - Lost Communication with Engine Control Module (ECM)
U0140:00 - Lost Communication with Body Control Module (BCM)
U0151:00 - Lost Communication with Restraints Control Module (RCM)
U0155:00 - Lost Communication with Instrument Panel Cluster (IPC)
U0402:68 - Invalid Data Received from Transmission Control Module (TCM)
U3013:16 - Body Control Module (BCM) Input Power "C" Circuit Voltage Below Threshold

After looking at a wiring diagram, he inspected for harness damage in the driver's kick panel area since both HS2-CAN circuits (VDB25, VDB26) were affected. He found broken wires in the harness.

Confirmed repair: The technician repaired the wiring and cleared the DTCs. He verified that all warning lamps were off and went for a test drive. No DTCs returned. Fixed!

Reprinted with permission from ALLDATA.

About the Author

Richard Diegle | Senior Automotive Editor for ALLDATA

Rich Diegle has been in the automotive industry since 1978. After graduating from a local community college, he began working at a Nissan dealership as a used car technician. Since then, he’s worked as a Nissan and ASE master automotive technician, shop owner, marketing copywriter, automotive editor, public relations manager, instructor, ALLDATA Tech-Assist team manager, and a senior automotive editor.