What P2534 usually means
P2534 points to the ignition-switch run/start signal being too low for the module to trust. That matters because many modules decide whether to wake up, keep relays alive, authorize starter command, or stay powered during crank based on this exact signal. A weak run/start feed can therefore mimic battery, relay, or even immobilizer trouble when the actual fault is in the ignition-switch circuit or its power path.