Iridium Extreme 9575 Firmware

Iridium Extreme 9575 current firmware: HL21001
(Enter *#91# on your phone's keypad to find out the phone's firmware version)

Note: If your 9575 handset has firmware version HL17001, it is strongly recommended that a firmware update is done as soon as possible.

Download the firmware update tool and instructions:


  • Iridium Extreme (9575 and 9575N) with f/w HL11001 and later
  • NOT compatible with the Extreme PTT, more info
  • Upgrade tool was tested on Windows 10

List of changes in HL21001:

  • Added optional audible indication of network connectivity status changes (user-configurable).
  • Improved communication channel selection algorithm used when establishing a connection with the network in telephony mode.
  • Added stronger validation checking of periodic radio calibration changes before storing to persistent memory in telephony mode.

WARNING, please read!

  • Read the entire document with instructions before attempting an upgrade!
  • All firmware upgrades, tools and instructions have been designed, produced, and provided by Iridium Communications, Inc. By performing a firmware upgrade, you will assume all and any risk. Your equipment may be damaged or bricked and costly repairs may be required. Sattrans USA shall not be responsible for any damage to your equipment and/or costs of repair/replacement as a result of firmware upgrades.

Contact us at if you have any questions.

List of changes in previous versions:


  • Leveraged enhancements offered by the Iridium NEXT constellation to improve network connectivity and improve reception of transceiver ring notifications from the core network.
  • Updated the Iridium branding content in Upgrade Tool with new graphics
  • Fixed an issue preventing display of predictive help content.
  • Corrected an issue preventing display of firmware version in French.


  • Resolved an issue wherein when the user attempted to enter the SMS menu when the outbox on the SIM was full the handset would reboot.
  • Enhanced GPS receiver performance when handset is powered from external sources including docking stations.
  • Addressed an issue where channel assignments were inadvertently being discarded in some situations thereby improving overall handset performance.
  • Modified battery charging algorithm to ensure compliance with battery specifications.


  • Improved accuracy of reporting when SMS storage on the SIM has reached capacity.
  • Added functionality to allow short codes to be stored in the phonebook, used from the phonebook, and dialed directly.
  • Improved responsiveness to power button press to turn the handset off.
  • Fixed an issue where Location Based Services would not work correctly after a power cycle with the charger connected.
  • Improved reporting of signal strength on the user interface and the AT interface.
  • Fixed an issue where a remote DTMF button press could un-mute a local handset.
  • Use of SBD services is now permitted when no SIM card is present in the handset. (Note: Mobile-Terminated SBD messages are not supported on the Iridium Extreme handset.)
  • Other minor changes (read the instructions document).


  • Calls to the emergency services number “000” are now are permitted when no SIM card is present in the handset.
  • Fixed an issue where sending an SMS at the same time that an SMS was being received would cause an error.
  • Corrected indication of units of distance (meter vs kilometer) in Location Based Services reporting message.
  • Access to the functionality of the AT commands CLIP and CLIR was added to the Intelligent Peripheral protocol.
  • Fixed condition that prevented retrieval of the SIM ICCID using the Intelligent Peripheral protocol.
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