Psa Interface Checker 440 Link [VERIFIED 2025]

The interface draws power from the vehicle’s OBD port. If your PSA vehicle’s battery is below 11.5V, the interface’s internal voltage regulator will fail to maintain the CAN bus termination voltage. A weak battery is a frequently overlooked reason for a random 440 link loss.

If you are staring at an error message, do not immediately assume your interface is dead. Here are the most common culprits:

The interface link uses a fixed thread pool. If all threads are stuck on long-running operations, the checker’s request is queued but never serviced, leading to a 440 after the checker’s own timeout. psa interface checker 440 link

Restart the link connector service:

systemctl restart psa-link-connector-440

Increase max_threads from 10 to 25 in link_config_440.yaml. The interface draws power from the vehicle’s OBD port

The term "link" is not just jargon; it is a technical description of the multiplexed network. PSA vehicles use several CAN (Controller Area Network) buses: CAN High, CAN Low, Comfort CAN, and Body CAN. The Interface Checker 440 link refers to the successful termination and data exchange on these buses.

For the link to be considered "active," three conditions must be met: Increase max_threads from 10 to 25 in link_config_440

SQL example (if using relational store):

DELETE FROM idempotency_registry WHERE key LIKE 'psa_checker_440_%' AND created_at < NOW() - INTERVAL '1 hour';

Report ID: PSA-IC-440-2026-04-12-001
Date: 12-Apr-2026
Test Engineer: J. Chen
System: PSA Skid Unit #3 – Control Interface
Link Under Test: Link 440 (Primary Control-to-Checker Path)