Mitsubishi Trium: Secret Codes and Tricks for All Vintage Models — Complete Guide 2026

This is the definitive guide to Mitsubishi Trium secret codes for vintage phones. Mitsubishi — the Japanese electronics giant — produced GSM phones for the European market between 1997 and 2003 under the Trium brand (Trium = Tri-band + UM = Universal Mobile). The Mitsubishi code system is unique compared to other brands — it uses two distinct families: codes with hold * for the standard Trium series, and codes with hold C for the MTD30 model. This guide includes the very rare Net Monitor codes, the engineering secret menu and verified network unlock procedures.


How the Mitsubishi Trium Code System Works — Read First

Mitsubishi Trium uses two access methods:

Standard Trium series (MT30, MT20D, MT060, M230, M250, MT360, Eclipse, Neptune):

  • Hold * then type the number → code activates

MTD30 model (specific):

  • Hold C then type the number → code activates

Brand name note: "Trium" was Mitsubishi's European brand for GSM phones. In Japan the same phones were sold under different names. When Mitsubishi exited the mobile phone market in 2003-2004, Trium models immediately became collector's items.


Universal Mitsubishi Trium Codes — Standard Series (hold *)

Code Function
*#06# Display IMEI code
*#0000# Language reset — restores the language set by the distributor
Hold * + 5806 Software version — firmware version
Hold * + 5807 Software version — variant (slightly different display)
Hold * + 5472 Data cable test mode
Hold * + 4329 NETMONITOR enable/disable — toggle network monitor
Hold * + 621342 NETMONITOR 2 enable/disable — second network monitor toggle
Hold * + 3926 Immediate shutdown

The Mitsubishi Trium Net Monitor — What It Shows and How to Use It

The Net Monitor is the most important and interesting code on the Trium series. Activated with:

Activation: hold * then type 4329

The Net Monitor shows in real time:

  • Cell ID — identifier of the GSM cell the phone is connected to
  • LAC (Location Area Code)
  • MCC (Mobile Country Code) — identifies the country
  • MNC (Mobile Network Code) — identifies the operator
  • Signal strength in dBm — much more precise than graphic bars
  • RF channel being used

Deactivation: hold * + 4329 again (it's a toggle).

The second Net Monitor (621342) shows additional parameters or a different view of the same data — useful for comparison.


Mitsubishi Trium Network Unlock — Full Procedure

Main method (all Trium models):

  1. Switch the phone off
  2. Remove the SIM card
  3. Switch the phone on without SIM
  4. Hold * and without releasing type 787292 (or 787295 on some models)
  5. The hidden menu "Unlock Network" appears
  6. Select YES
  7. Enter the NCK unlock code
  8. Phone is now unlocked

Variant: some models use 787292, others 787295. If one doesn't work, try the other.

Alternative SP lock method (very old firmware only):

**04*PIN*PIN*PIN# — this trick works only on Trium phones with very old firmware (generally pre-2000). It exploits a firmware bug that interpreted the PIN change as a reset of the SP lock counter. On updated firmware this bug is fixed and the code no longer has this effect.


Mitsubishi Trium MT30 (M5) — Full Secret Codes

The Mitsubishi Trium MT30 (1999-2000) was one of the first Trium GSM phones — compact design, monochrome screen, excellent battery life. Also called "M5" in internal technical documents.

IMEI: *#06#

Language reset: *#0000#

Software version: hold * + 5806

Net Monitor: hold * + 4329

Network unlock: hold * + 787292 (without SIM) → YES → NCK

EFR: *3370# / #3370#

MT30 collector note: The MT30 was the first Trium with an internal antenna — unusual for the time. The software version code shows the build date which allows identifying first series (1999) from later versions (2000-2001).

👉 View Mitsubishi Trium MT30 available at Infosate


Mitsubishi Trium MT20D — Secret Codes

The Mitsubishi Trium MT20D (1999) was the entry-level Trium model — small display but extremely rugged.

IMEI: *#06# | Language: *#0000# | SW version: hold * + 5806

Net Monitor: hold * + 4329 | EFR: *3370# / #3370#

Network unlock: hold * + 787292 (without SIM) → YES → NCK


Mitsubishi Trium MT060 (M6, Mystral) — Full Secret Codes

The Mitsubishi Trium MT060 (2000-2001), also called "M6" or "Mystral", was the MT30 successor — larger display, more modern design.

IMEI: *#06# | Language: *#0000# | SW version: hold * + 5806

Net Monitor 1: hold * + 4329 | Net Monitor 2: hold * + 621342

Data cable test mode: hold * + 5472 | EFR: *3370# / #3370#

Network unlock: hold * + 787292 (without SIM) → YES → NCK


Mitsubishi Trium M230 (Mars) — Full Secret Codes

The Mitsubishi Trium M230 / Mars (2001) was the most popular Trium in Europe — elegant design, colour display, polyphonic ringtones. It was also the best-selling model of the entire Trium range.

IMEI: *#06#

Language reset: *#0000#

Software version: hold * + 5806

Net Monitor: hold * + 4329

Net Monitor 2: hold * + 621342

Network unlock: hold * + 787292 (without SIM) → YES → NCK

EFR: *3370# / #3370#

Half Rate: *4720# / #4720#

M230 Mars collector note: The Mars was the Trium that brought colour displays to the series. The transition from monochrome to colour is visible by comparing firmware versions using the hold * + 5806 code.

👉 View Mitsubishi Trium M230 Mars available at Infosate


Mitsubishi Trium M250 (Neptune) — Secret Codes

The Mitsubishi Trium M250 / Neptune (2001) was the mid-range model — positioned between the Mars and Eclipse.

IMEI: *#06# | Language: *#0000# | SW: hold * + 5806

Net Monitor: hold * + 4329 | EFR: *3370# | Network unlock: hold * + 787292


Mitsubishi Trium MT360 (Aura) — Secret Codes

The Mitsubishi Trium MT360 / Aura (2002) was one of the last Trium models — modern design, advanced colour display, MMS support.

IMEI: *#06# | Language: *#0000# | SW: hold * + 5806

Net Monitor: hold * + 4329 | EFR: *3370# | Network unlock: hold * + 787292


Mitsubishi Trium Eclipse MT450 — Full Secret Codes

The Mitsubishi Trium Eclipse MT450 (2002) was the Trium flagship — the most elegant and advanced, with integrated camera.

IMEI: *#06#

Language reset: *#0000#

Software version: hold * + 5806

Net Monitor: hold * + 4329

Net Monitor 2: hold * + 621342

Network unlock: hold * + 787292 (without SIM) → YES → NCK

EFR: *3370# / #3370#

Eclipse collector note: The most sought-after Trium by collectors for its design and advanced specs. The NCK unlock code is IMEI-specific — calculated from the IMEI using the Mitsubishi algorithm.

👉 View Mitsubishi Trium Eclipse available at Infosate


Mitsubishi MTD30 — Secret Codes (Different C System!)

The Mitsubishi MTD30 uses a completely different code system from the rest of the Trium series — instead of hold *, it uses hold C:

IMEI: *#06#

Code Function
Hold C + 379 Monitor Mode
Hold C + 987 Secret menu
Hold C + 597 Version number
Hold C + 499 Phase 1 and 2
Hold C + 179 Warm start (soft reboot)
Hold C + 999 Immediate shutdown
Hold C + 787090 Unlock menu

MTD30 network unlock: hold C + 787090 → YES → NCK

Important MTD30 difference: The MTD30 is based on a completely different hardware platform from the rest of the Trium series. For this reason it uses the C key instead of * for special codes. All hold * + XXXX codes from the standard Trium series do NOT work on the MTD30.

MTD30 Monitor Mode: the code hold C + 379 activates the Monitor Mode — equivalent to the Net Monitor but specific to the MTD30 platform. Shows Cell ID, LAC, signal strength and network parameters.


Getting the NCK Code for Your Mitsubishi Trium

The Mitsubishi NCK code is calculated from the phone's IMEI using the specific Mitsubishi algorithm. No universal code exists. Available from online unlocking services by providing the IMEI.

How many attempts do I have? Vintage Trium phones generally allow 5-10 attempts. After exceeding attempts, "Contact provider" appears permanently.


Universal GSM Codes — Valid for All Mitsubishi Trium GSM

PIN and PUK management:

  • Change PIN: **04*[old]*[new]*[new]#
  • Change PIN2: **042*[old]*[new]*[new]#
  • Unlock with PUK: **05*[PUK]*[new PIN]*[new PIN]#

Call forwarding:

Code Function
##002# Cancel all call forwarding
##004# Cancel conditional forwarding
*#21# Check unconditional forwarding
*#61# Check "no answer" forwarding
*#62# Check "not reachable" forwarding
*#67# Check "busy" forwarding
**21*[number]# Activate unconditional forwarding

Call barring (default password 0000):

  • *33*(password)# → bar outgoing calls
  • *353*(password)# → bar incoming calls
  • *43# / #43# → activate/deactivate call waiting

EFR and Half Rate:

  • *3370# → enable Enhanced Full Rate (better audio)
  • #3370# → disable EFR
  • *4720# → enable Half Rate (battery saving)
  • #4720# → disable Half Rate

Frequently Asked Questions

What does "Trium" mean in the brand name? "Trium" is a combination of "TRI" (Tri-band GSM 900/1800/1900) and "UM" (Universal Mobile) — a branding choice that emphasised the phone's tri-band capabilities, advanced for the era.

Why does the MTD30 use hold C instead of hold *? The MTD30 is based on a completely different hardware platform from the rest of the Trium series. The C key corresponds to the Clear/Cancel button on the keyboard — Mitsubishi used this key as the engineering access point for this specific platform.

Does the **04*PIN*PIN*PIN# code really unlock the SP lock? Only on Trium phones with very old firmware (generally pre-2000). It exploits a firmware bug that interpreted the PIN change as a SP lock counter reset. On updated firmware this bug has been fixed and the code no longer has this effect.

Did Mitsubishi exit the mobile phone market? Yes — Mitsubishi announced its withdrawal from the European mobile phone market in 2002-2003. The decision was similar to Panasonic's — inability to compete with Nokia, Sony Ericsson and Samsung. Trium models remaining unsold quickly became collector's items.

What's the difference between the Net Monitor (4329) and Net Monitor 2 (621342)? Both show GSM network parameters but with different layouts and potentially different sets of data. Net Monitor 1 tends to show the primary network parameters (Cell ID, LAC, signal strength). Net Monitor 2 may show additional information about neighbouring cells and alternative network parameters. Both are toggle functions — the same code activates and deactivates.


Original Vintage Mitsubishi Trium at Infosate

At Infosate you'll find a selection of original vintage Mitsubishi Trium phones — MT30, M230 Mars, M250 Neptune, Eclipse MT450 and other iconic models of the Japanese brand, all verified before shipping.

👉 Explore the Mitsubishi collection at Infosate

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