How to Dump N67 Memory Contents

If you have an Alfa Romeo 145, 146, 155, 164, GTV or Spider and you need to add an extra remote key to operate the central locking then you will need a password to unlock the receiver. This password is usually on the back of the Alfa Romeo CODE CARD.

The module appears to be manufactured by TRW Sipea. The model number is listed as TRW MS 3244-C 7549. If you have a board similar to this these instructions and the decoder listed here can probably be used.

Code card
Alfa Romeo CODE CARD

If you have lost the CODE CARD then you will need to dump the contents of the memory from the N67 module. To do this you will need to:

  1. Remove the N67 from the car
  2. Attach an EEPROM reader using a test clip
  3. Read the contents of the EEPROM and save it
  4. Decode the contents of the EEPROM using the decoder
  5. Plug the N67 back into the car, and enter the decoded unlock code

Before you get started make sure you have:

Removing the N67 from the car

The N67 is located behind the cabin lights. In order to remove it you will need to carefully use a flat headed screwdriver to pry the unit open using a notch on the right of the unit. From here you can disconnect the lights and put these to one side.

Two hex headed cap screws should now be visible. Undo these and the whole plastic frame should drop down. Carefully unplug the N67 from the wires. Now using a Phillips screwdriver (PH1) flip over the unit and undo the 3 screws. This will give you the PCB (printed circuit board) in a small plastic box. You can remove the PCB by very carefully prying back the plastic clips.

Attach an EEPROM reader using a test clip

N67 pcb
N67 PCB with 93LC46B serial EEPROM highlighted

Attach the test clip to the 93LC46B highlighted in a red circle in the PCB figure. The SOIC package can be difficult to get a good connection. If it is not connected well then it will not be possible to read from the memory. To verify it is seated properly a continuity check can be done with a multimeter to each pin.

To check the continuity each wire coming from the test clip must be probed to the correct place on the board (it is not possible to probe the chip directly as the test clip covers all of it). If there is continuity for all of the pins listed then it will be possible to read the memory. Follow the figure with the PCB traces highlighted in colour.

N67 pcb highlighted
N67 PCB with 93LC46B traces highlighted in colour.

Connect the test leads to the EEPROM reader. Pin 1 is marked Pink in the diagram, 4 blue, 5 green and 8 yellow. Ensure the software detects the EEPROM reader hardware. Configure it to read an 93LC46B and then read the EEPROM.

If the dump is all 0's, or F's then you have a connection problem. Go back and ensure there is proper continuity. Provided it looks successful save the dump.

Decode the contents of the EEPROM using the

Upload the saved dump to the decoder. Make a note of the unlock codes.

Plug the N67 back into the car, and enter the decoded unlock code

Clip the N67 PCB back into the plastic case and screw this case into the rest of the plastic frame. Connect the N67 back to the cars harness and then screw the frame to the roof using the hex headed bolts. Now connect the light unit back to the harness and insert the left side into the frame first and gently push into place

The memory needs to be opened to program a new key. It can be opened as follows:

  1. press the button on receiver (small hole next to LED) for approximately 2 seconds; LED will flash for the whole time in which the button is pressed;
  2. release button; after approximately 2 seconds the LED will flash once indicating the possibility to enter the first digit of the password.
  3. press the button of the receiver the number of times corresponding to the first figure of the password (for example if the Password is press 5 times). Each time the button is pressed the LED lights up briefly to confirm;
  4. after approximately 2 seconds from the last press on the button (the fifth in the example) the led will flash again to ask for the next figure.
  5. proceed as described above for all the four figures. It should be noted that when the password (see example) contains a "0" there is no need to press the button, simply wait for the next request.

When the Password hase been entered, the LED will behave as follows:

A new key can now be added to the unit:

  1. press and hold receiver button on the ceiling light. The LED will flash
  2. keeping the receiver button pushed, press the key's transmitter button. The LED of the key's transmitter must flash once;
  3. the LED on the receiver will light continuously indicating that the code has been memorised: the button on the receiver can now be released.

If you don't know the unlock code for the new key now is a good time to find out by repeating the entire how-to to get the new memory dump.