Install the C4-D

This page has been updated on the 11 April 2011.

Insert the SIM card

Caution: Disable the SIM security (pin code) with a cell phone before using it with the C4-D.

1. Open the top cover
2. Place the SIM card
3. Push the SIM forward

Note: Make sure the gold contacts of the SIM card are face down. Then gently slide the SIM card completely into the holder. The angled corner of the SIM card should be inserted as shown. Improperly inserting the SIM will result in the C4-D not recognising the SIM card.

Where to place

GPS antenna

The GPS antenna must be mounted on a location with a clear line of sight. Best results are usually obtained by mounting it outside but if you opt for interior mounting beware of electromagnetic interference and metallic parts. For instance it can be mounted in the dash or the “A” pillar panel.

Note: Do not place the GPS antenna in/on the dash if the vehicle has a solar reflective wind shield.


The best location for the C4-D is inside the dashboard or embedded in the console area so as to make it as inaccessible to thieves as possible.

Cabling and wiring

MicroFIT pin out definition

Signal C4-D pin out Direction Grey DB9 Pin out (for CAN)
VBAT power 18 Input
Ground power 17 Ground
Ignition 16 In
Alarm 15 In
1-Wire N 14 In/Out
1-Wire P 13 In/Out
RS232_RTS1 12 Out
RS232_CTS1 11 In
RS232_RXD1 10 In
RS232_TXD1 9 Out
Ground 8 Ground 5
Input 1 / K-Line 7 In
Input 2 6 In
Input 3 5 In
RS232_RXD2 / CAN HIGH 4 In 3
RS232_TXD2 / CAN LOW 3 Out 2
Output 1 2 Out
Output 2 1 Out

Cable description

Wrapper Wire color and description
Red DB9 Black [COM1]
Brown → Ground RS232
Yellow → TX – RS232
Orange → RX – RS232
Red → CTS RS232
White → RTS RS232

DB9 Grey [COM3]
Brown → Ground RS232
Green → RX – RS232 / CAN HIGH
Blue → TX – RS232 / CAN LOW
Grey → 1Wire
Black → 1Wire

Blue Grey → Output 1 (ground)
White → Output 2 (ground)
Purple → Input 3 (positive)
Blue → Input 2 (ground)
Green → Input 1 (ground) / K-Line (provides 6V)
Orange → Input 4/Alarm (ground)

Black Red → Permanent positive (8-30 V)
Black → Ground (battery)
White → Ignition

Connection steps

Mobile Devices recommends you connect the device directly to the external power supply and to add a fuse (2A) on the permanent positive.

  1. Connect the black wire (black wrapper) to the Ground.
  2. Connect the red wire (black wrapper) to the 12/24V DC power.
  3. Connect the white wire (black wrapper) to the ignition.
  4. Tape and insulate any loose unconnected wires.


  • Turn car ignition off before making connections.
  • Inputs must be free.
  • Use a common ground point for all ground wires.
  • Define the best wiring if a circuit breaker is installed.
  • Tape and insulate the GPS antenna connector.

Control the installation

To check if the device is properly installed, check the front LEDs.

  • LED1 (Green color) – External power
    This LED should be ON and solid.
    • If OFF the C4-D is not connected to an external power source.
  • LED2 (Orange color) – System status
    This LED should be ON and solid.
    • If OFF but the LED 1 is green the C4-D is sleeping.
  • LED3 (Green color) – GPRS status
    This LED should blink slowly 3 seconds ON, 3 seconds OFF.
    • If OFF, the device is restarting or the modem is not started.
    • If OFF 3 sec and ON shortly the C4-D can not connect to the GPRS network. If so check the SIM card and the APN.
  • LED4 (Orange color) – GPS status
    This LED should blink 3 sec ON, 3 sec OFF.
    • If OFF, the device is restarting or the GPS module is not started.
    • If OFF 3 sec and ON shortly the C4-D can not fix the GPS. If so check antenna and the GPS parameters.