MRT-2275 — Vehicle Installation GuideUpdated 18 hours ago

miTrail MRT-2275 — Vehicle Installation Guide

Install the miTrail MRT-2275 GPS tracker in cars, SUVs, and light trucks. This guide covers wiring, mounting, LED status, and quick checks for a fast, foolproof setup.

1) What’s Included

MRT-2275 tracker (waterproof, IP67-class enclosure).
8‑wire installation harness (user cable) with power, I/O, and RS‑232 leads

Key wire colors and functions

Red

Power input 8–32V DC (battery+)

Black

Ground to vehicle chassis

White

Ignition input, positive trigger (ACC/RUN)

Yellow

Digital input, negative trigger (optional)

Blue

Digital output1, open‑drain low‑side, 150mA max with latch (optional)

Green

Digital output2, open‑drain low‑side, 150mA max (optional)

Violet

RS‑232 TXD (advanced)

Grey

RS‑232 RXD (advanced)

2) Before You Begin

Park safely, ignition OFF, and identify a fused constant +12V/+24V source and a clean bare‑metal chassis ground point.
Choose a hidden mounting location with the device “top” facing up toward the sky under plastic trim, avoiding solid metal directly above for best GNSS signal.
The SIM is pre-installed and PIN-disabled; no SIM handling is needed.

3) Step-by-Step Installation

Step 1 — Connect Power and Ground

Red → fused constant battery+ (supports 8–32V; suitable for 12V/24V systems without a transformer).
Black → solid chassis ground on bare metal (not painted hardware).

What to expect: The device powers on automatically when external power is applied; if external power is removed it runs on the internal backup battery and will report before powering down when depleted.

Quick check: Tug-test connections and verify the fuse is installed near the power source per automotive best practice.

Step 2 — Connect Ignition Sense (Recommended)

White → a circuit that is +12V/+24V only when the key is in ACC/RUN (radio ACC is acceptable).

Why: Enables active reporting when ignition is ON and power saving when OFF.

Quick check: Key to ACC/RUN: White shows 5.0–32V (Active); Key OFF: 0–3V or open (Inactive).

Step 3 — LED Status Check

After power-up, observe LEDs:

CEL (cellular): fast flash = searching; slow flash = registered; solid ON = SIM PIN required (should not occur with pre-installed SIM).
GPS: fast flash = searching satellites; solid ON = GPS fix; OFF = GPS chip powered off.

Typical flash timing references for GV75 series: fast ≈100ms ON/200ms OFF; slow ≈200ms ON/1000ms OFF (behavior may vary by firmware).

Allow several minutes with some sky view for the first GPS fix.

Step 4 — Final Mount and Tidy-Up

Once CEL shows network registration (slow flash) and GPS has fixed at least once (solid), secure the device at the planned location with top facing up under plastic trim.

Loom and secure the harness away from sharp edges, heat, and moving parts; reinstall trims.

Technical Notes (For Installers)

Operating voltage: 8–32V DC; designed for 12V/24V vehicles without external transformers.
Ignition input (White): positive trigger; Active 5.0–32V; Inactive 0–3V/open.
Digital input (Yellow): negative trigger; Active 0–0.8V; Inactive 1.7–32V/open.
Digital outputs (Blue latched, Green standard): open-drain low-side, 0.15A max sink each; pull-up/load to ≤32V; latch persists across restarts when main and backup power present; outputs internally pulled up to PWR by a diode so no external flyback diode is needed for inductive loads.
RS‑232 interface: valid RS‑232 levels ±3V to ±15V; −3V to +3V invalid; +3V to +15V corresponds to TTL logic 0, −3V to −15V to TTL logic 1.
LEDs: CEL/GPS/PWR definitions per GV75 series; fast and slow flash timing as typical references above.

Was this article helpful?

Yes