JLG 1001118118 is a control‑ground module used in JLG aerial and forklift equipment, typically interfacing with the main controller board via I/O signals and providing grounding protection for the drive electronics. Common failure points for this class of modules include burned or cracked power input traces, degraded solder joints on the I/O headers, and corrosion or shorting on the ground plane due to moisture ingress. First‑check diagnostics: verify 24 V DC supply voltage at the module pins, inspect all I/O connectors for continuity and proper seating, examine the board under magnification for visible damage or residue, and review any diagnostic codes from the host controller that reference the control‑ground interface.[oss-gpt-20b]