Turn Signals
WARNING: This page is about a different car, the 2003 Pontiac Aztek and 2003 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.
The IPC illuminates the right or left turn signal indicator when the IPC detects a turn signal request or a hazard request. If the IPC determines that the turn signal is active for more than 1.21 km (0.75 mi), the IPC sends a class 2 message to the radio in order to activate the audible warning.