⚠
warning HP
Error Code Toner Low Alert (red led blinking)
The toner cartridge has reached its estimated life based on print volume.
? What Causes This
Low remaining toner due to printing frequency and type.
✓ How to Fix It
Prepare a replacement toner cartridge for an upcoming swap. Continue use temporarily if needed.
Source: page 130 of the official manual
From the manual
This error code appears in:
HP Laserjet Mfp M438