P0A73 Hybrid/EV Powertrain Active Discharge Circuit

P0A73 indicates a Hybrid/EV powertrain active discharge circuit problem. The system cannot confirm the circuit that discharges high-voltage bus energy after shutdown.

Code status

Needs verification

Not yet verified against SAE J2012_202509 / J2012DA. Treat unverified rows as a lookup aid, not repair authority.

System: Hybrid / EV
Scope: iso-sae-controlled-p0
Standard: SAE J2012 / ISO 15031-6
Source: legacy-import

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not assume the high-voltage bus is discharged when an active discharge circuit code is present.

Useful checks before replacing parts

Check active discharge command, DC bus voltage decay, inverter status, contactor state, freeze-frame data, and related high-voltage safety or isolation codes.
Inspect inverter or discharge circuit connectors, low-voltage control wiring, module grounds, interlock status, water intrusion, and service disconnect condition.
Verify voltage decay only with approved high-voltage procedures to separate discharge circuit, contactor, inverter, and sensing faults.

Related OBD-II codes

These nearby hybrid / ev entries can help compare wording and fault area. They may share the same verification status as the source database.