Unstable Idle When Hot Nissan Terrano D22

Okay, everyone, at my workplace we have a Nissan Terrano D22 2.5 turbo diesel, and it turns out that when the engine is cold, it starts up perfectly with a very stable idle, but once the engine warms up, the idle becomes very unstable. Does anyone have any information that could help me figure out what the problem might be? The check engine light isn't on.

Thanks

Help!!!

Perform a cleaning of the intake manifold and the idle control unit. Check for air leaks in the intake system. That's a start. Pay attention to the check engine light because sometimes it doesn't indicate sensor malfunctions, out-of-range readings, etc. Now you'll have to check the mass airflow sensor if it has one