The 1N6267HE3/54: At that waveform, the peak pulse current reaches 139A, and the clamping voltage sits at 10.8V maximum — the diode clamps the transient to that level regardless of surge amplitude up to its rated 139A, protecting downstream circuitry from voltage spikes above 10.8V on a 5.5V nominal standoff rail.
DO-201AA package and automotive thermal margin
With a junction temperature rating of -55°C to 175°C (TJ), the part sits in the upper AEC-Q101 temperature band — the upper end of the range covers under-hood and engine-adjacent enclosures that see elevated ambient, though the actual board-level derating must be confirmed against the specific mounting and airflow in the application.
Sourcing an obsolete automotive TVS diode
Any cross-candidate from a different manufacturer series would require re-evaluation of standoff, clamping, and peak pulse current against the board's surge environment, since the AEC-Q101 qualification is not a universal property across suppliers.