The OKI Telecom 28100‑PXO‑A21‑M1 is an automotive transmission control unit (TCU) used in 1992–1993 Honda Accord models. Common failure modes include electrolyte leakage from degraded electrolytic capacitors that corrode copper traces, resulting in intermittent or total loss of communication with the engine control module. Inspect the board for bulging or leaking capacitors and check for burn marks on the power supply rails; verify proper voltage levels at the main VCC pins and confirm that all I/O signals are within spec using a logic analyzer. If no physical damage is found, run a diagnostic scan to read fault codes and test the TCU’s internal communication bus against the vehicle’s CAN network.[oss-gpt-20b]